The Effect of Testosterone on Cardiovascular Biomarkers in the Testosterone Trials

The Effect of Testosterone on Cardiovascular Biomarkers in the Testosterone Trials Abstract Context Studies of the possible cardiovascular risk of testosterone treatment are inconclusive. Objective To determine the effect of testosterone treatment on cardiovascular biomarkers in older men with low testosterone. Design Double-blind, placebo-controlled trial. Setting Twelve academic medical centers in the United States. Participants In all, 788 men ≥65 years old with an average of two serum testosterone levels <275 ng/dL who were enrolled in The Testosterone Trials. Intervention Testosterone gel, the dose adjusted to maintain the testosterone level in the normal range for young men, or placebo gel for 12 months. Main Outcome Measures Serum markers of cardiovascular risk, including lipids and markers of glucose metabolism, fibrinolysis, inflammation, and myocardial damage. Results Compared with placebo, testosterone treatment significantly decreased total cholesterol (adjusted mean difference, −6.1 mg/dL; P < 0.001), high-density lipoprotein cholesterol (adjusted mean difference, −2.0 mg/dL; P < 0.001), and low-density lipoprotein cholesterol (adjusted mean difference, −2.3 mg/dL; P = 0.051) from baseline to month 12. Testosterone also slightly but significantly decreased fasting insulin (adjusted mean difference, −1.7 µIU/mL; P = 0.02) and homeostatic model assessment‒insulin resistance (adjusted mean difference, −0.6; P = 0.03). Testosterone did not change triglycerides, d-dimer, C-reactive protein, interleukin 6, troponin, glucose, or hemoglobin A1c levels more than placebo. Conclusions and Relevance Testosterone treatment of 1 year in older men with low testosterone was associated with small reductions in cholesterol and insulin but not with other glucose markers, markers of inflammation or fibrinolysis, or troponin. The clinical importance of these findings is unclear and requires a larger trial of clinical outcomes. The effect of testosterone treatment on cardiovascular risk is uncertain. Some retrospective studies using electronic medical records have reported more cardiovascular adverse events in men taking testosterone than in men not taking it, but others have not (1–4). These studies all have the limitations of not being controlled for diagnosis or treatment. One clinical trial of testosterone in frail older men was stopped early because more cardiovascular adverse events occurred in men taking testosterone than in men taking placebo (5), but another similar trial reported few adverse cardiovascular events (6). Meta-analyses of clinical trials have generally not shown more adverse cardiovascular events in men taking testosterone than in men taking placebo, but none of the individual trials was designed prospectively to capture these events (7, 8). The Testosterone Trials (TTrials) were a group of seven coordinated trials involving 788 men to determine the efficacy of raising the serum testosterone levels of men ≥65 years of age to normal levels for young men for 1 year (9). Although the numbers of men who experienced major cardiovascular adverse events were similar in the two treatment arms in all men in the TTrials (10), testosterone treatment was associated with a greater increase in noncalcified coronary artery plaque volume by computed tomographic angiography in the 138 men who participated in the Cardiovascular Trial (11). If testosterone does affect cardiovascular risk, it might do so by altering any one of several cardiovascular risk factors, such as lipids, glucose metabolism, coagulation, and inflammation. We therefore measured several biomarkers of cardiovascular risk at baseline and after 3 and 12 months of treatment in all men participating in the TTrials. Methods Study design The TTrials were a coordinated group of seven double-blind placebo-controlled trials designed to evaluate the efficacy of testosterone treatment in men ≥65 years of age who had age-related low testosterone levels (9). To participate in the TTrials, a man had to qualify for at least one of the three main trials (Sexual Function, Physical Function, and Vitality). Those who qualified could also participate in any of the other trials if they met the respective entry criteria. The participants were allocated to receive testosterone or placebo gel for 1 year. This report describes the serum levels of cardiovascular biomarkers at baseline and months 3 and 12 in all men participating in the TTrials. The institutional review boards of the 12 participating sites approved the TTrials protocols. Before trial-related procedures were conducted, all participants provided written informed consent. An independent Data and Safety Monitoring Board oversaw participant safety and trial conduct. Participants The inclusion and exclusion criteria have been published (9). In brief, men were included who were ≥65 years of age, had serum testosterone levels that averaged <275 ng/dL in two morning samples, and had subjective and objective evidence of sexual dysfunction, physical dysfunction, and/or reduced vitality. Men were excluded if they were at moderate or high risk for prostate cancer; had a myocardial infarction within the previous 3 months; or had a blood pressure level >160 mm Hg systolic or 100 mm Hg diastolic, serum creatinine level >2.2 mg/dL, or a hemoglobin A1c (HbA1c) value >8.5%. Men who were taking medications to control blood pressure or serum lipid levels were not excluded. Testosterone treatment Men were allocated to receive either testosterone as a 1% gel in a pump bottle (testosterone gel, AndroGel; AbbVie, North Chicago, IL) or similar placebo gel in a double-blind fashion for 1 year. The initial dose of testosterone was 5 g a day. The dose was adjusted to keep the serum concentration within the normal range for young men on the basis of measurement in a central laboratory (Quest Clinical Trials, Valencia, CA) at months 1, 2, 3, 6, and 9. To maintain the blind, when the dose was changed in a man taking testosterone, the dose was also changed in a man taking placebo. Assessments Blood for cardiovascular biomarkers was drawn fasting in the morning at baseline and at months 3 and 12; serum was stored at −80°C. Biomarker assays were performed at the Laboratory for Clinical Biochemistry Research, University of Vermont, with the exception of the troponin I assay, which was performed at the University of Minnesota. Samples from the same participant were assayed in the same batch. Clinical variables were measured at baseline and months 3, 6, 9, and 12. Lipid assays Lipid assays included total cholesterol [interassay coefficient of variation (CV) range, 1.45% to 2.33%], high-density lipoprotein (HDL) cholesterol (interassay CV range, 1.69% to 2.26%), and triglycerides (interassay CV range, 1.95% to 2.57%) using enzymatic colorimetric assays (Cobas Integra 400; Roche Diagnostics, Indianapolis, IN). Low-density lipoprotein (LDL) cholesterol was calculated using the Friedewald formula when the triglyceride concentration was <400 mg/dL. Glucose, insulin, and HbA1c assays Glucose concentration was determined using a hexokinase method (Cobas Integra 400, Roche Diagnostics) (interassay CV range, 2.24% to 4.55%). Insulin was measured by electrochemiluminescence immunoassay (Elecsys 2010; Roche Diagnostics) (interassay CV range, 2.39% to 2.78%). HbA1c was measured in frozen whole blood samples by turbidimetric inhibition immunoassay (Tina-quant HgA1C Gen 2 Whole Blood application, Cobas Integra 400; Roche Diagnostics) (interassay CV range, 1.63% to 3.25%). Assays of markers of inflammation C-reactive protein (CRP) was measured using a high-sensitivity particle enhanced immunonephelometric assay (BN II nephelometer; Siemens, Inc., Deerfield, IL) (interassay CV range, 3.32% to 4.64%). Interleukin (IL)-6 was measured by electrochemiluminescence immunoassay (Meso Scale Diagnostics, Rockville, MD) (interassay CV range, 8.14% to 11.95%). d-dimer and troponin assays d -dimer was measured using an immunoturbidimetric assay (STA-R Evolution, Diagnostica Stago, Parsippany, NJ) (interassay CV range, 2.73% to 20.14%). Troponin I was measured using a high-sensitivity immunoassay (ARCHITECT STAT high-sensitive troponin I assay; Abbott Laboratories, Abbott Park, IL). Statistical analyses The effects of testosterone were assessed using random effects models for longitudinal data. The models included visit time as a categorical variable and a single main effect for treatment and were adjusted for baseline values of each biomarker and all balancing variables used in the allocation procedure: study site, indicator variables of participation in each primary efficacy trial, baseline testosterone concentration (≤ or > 200 ng/dL), age (≤ or > 75 years), use of antidepressants, and use of phosphodiesterase-5 inhibitors. All participants who had at least one postbaseline value were included in the intent-to-treat analysis. We performed additional analyses of lipid markers excluding men who were not taking lipid-lowering medications at baseline but initiated them during the study; we also performed separate analyses of metabolic markers excluding men taking antidiabetic medications. Significance was assessed through the two-sided Wald test and confidence interval for the treatment effect. The treatment effect denotes the average difference in response by treatment arm across all visits (baseline and months 3 and 12). No adjustments were made for multiple testing. Results Participants and clinical measures TTrials enrollment was 788 men at 12 sites. The mean age at baseline was 72 years. Relatively high percentages were obese and had comorbid conditions, such as diabetes and hypertension, but the two treatment arms were well balanced for these conditions and related medications (Table 1). Testosterone treatment increased the serum testosterone concentration from unequivocally low at baseline to midnormal for young men by month 3 and maintained it at that level through month 12 (10). Compared with placebo, testosterone treatment did not significantly change weight (adjusted difference, 0.28 kg; P = 0.18), body mass index (adjusted difference, 0.09 kg/m2; P = 0.21), or waist/hip ratio (adjusted difference, 0.002; P = 0.46) (Table 2). Table 1. Characteristics of Participants at Baseline Characteristic  Treatment   Testosterone (n = 394)  Placebo (n = 394)  Demographics       Age, y  72 ± 5.7  72 ± 5.8   Height, cm  175 ± 7.1  175 ± 7.0   Weight, kg  95 ± 13.1  95 ± 14.0   BMI, kg/m2  31 ± 3.6  31 ± 3.5   BMI >30 kg/m2 (%)  251 (63.7%)  246 (62.4%)   Waist/hip ratio  1.0 ± 0.1  1.0 ± 0.1  Concomitant conditions       Diabetes, %  148 (37.6%)  144 (36.5%)   Hypertension, %  286 (72.6%)  279 (70.8%)   History of myocardial infarction  53 (13.5%)  63 (16.0%)   History of stroke  16 (4.1%)  17 (4.3%)  Medications       Antidiabetics  130 (33.0%)  131 (33.2%)   Lipid-lowering drugs  274 (69.5%)  273 (69.3%)  Characteristic  Treatment   Testosterone (n = 394)  Placebo (n = 394)  Demographics       Age, y  72 ± 5.7  72 ± 5.8   Height, cm  175 ± 7.1  175 ± 7.0   Weight, kg  95 ± 13.1  95 ± 14.0   BMI, kg/m2  31 ± 3.6  31 ± 3.5   BMI >30 kg/m2 (%)  251 (63.7%)  246 (62.4%)   Waist/hip ratio  1.0 ± 0.1  1.0 ± 0.1  Concomitant conditions       Diabetes, %  148 (37.6%)  144 (36.5%)   Hypertension, %  286 (72.6%)  279 (70.8%)   History of myocardial infarction  53 (13.5%)  63 (16.0%)   History of stroke  16 (4.1%)  17 (4.3%)  Medications       Antidiabetics  130 (33.0%)  131 (33.2%)   Lipid-lowering drugs  274 (69.5%)  273 (69.3%)  Values are mean ± standard deviation or no. (%). Abbreviation: BMI, body mass index. View Large Table 2. Clinical Measures Measure  Testosterone   Placebo   Difference in Change Over Timea (95% CI)  P Value  Baseline (n)  Month 3 (n)  Month 6 (n)  Month 9 (n)  Month 12 (n)  Baseline (n)  Month 3 (n)  Month 6 (n)  Month 9 (n)  Month 12 (n)  Weight, kg  94.8 ± 13.1 (394)  95.4 ± 12.9 (374)  94.6 ± 13.1 (367)  94.6 ± 12.9 (356)  94.1 ± 13.3 (367)  94.8 ± 14.0 (394)  94.7 ± 14.0 (371)  94.1 ± 14.1 (349)  93.5 ± 14.0 (341)  93.4 ± 14.1 (353)  0.28 (−0.13, 0.69)  0.18  BMI, kg/m2  31.0 ± 3.6 (394)  31.2 ± 3.6 (374)  30.9 ± 3.6 (367)  30.9 ± 3.6 (356)  30.8 ± 3.6 (367)  31.0 ± 3.6 (394)  30.9 ± 3.5 (371)  30.8 ± 3.6 (349)  30.7 ± 3.6 (341)  30.7 ± 3.7 (353)  0.09 (−0.05, 0.24)  0.21  Waist/hip ratio  1.0 ± 0.1 (394)  1.0 ± 0.1 (373)  1.0 ± 0.1 (367)  1.0 ± 0.1 (356)  1.0 ± 0.1 (366)  1.0 ± 0.1 (394)  1.0 ± 0.1 (369)  1.0 ± 0.1 (349)  1.0 ± 0.1 (342)  1.0 ± 0.1 (353)  −0.002 (−0.006, 0.003)  0.46  Measure  Testosterone   Placebo   Difference in Change Over Timea (95% CI)  P Value  Baseline (n)  Month 3 (n)  Month 6 (n)  Month 9 (n)  Month 12 (n)  Baseline (n)  Month 3 (n)  Month 6 (n)  Month 9 (n)  Month 12 (n)  Weight, kg  94.8 ± 13.1 (394)  95.4 ± 12.9 (374)  94.6 ± 13.1 (367)  94.6 ± 12.9 (356)  94.1 ± 13.3 (367)  94.8 ± 14.0 (394)  94.7 ± 14.0 (371)  94.1 ± 14.1 (349)  93.5 ± 14.0 (341)  93.4 ± 14.1 (353)  0.28 (−0.13, 0.69)  0.18  BMI, kg/m2  31.0 ± 3.6 (394)  31.2 ± 3.6 (374)  30.9 ± 3.6 (367)  30.9 ± 3.6 (356)  30.8 ± 3.6 (367)  31.0 ± 3.6 (394)  30.9 ± 3.5 (371)  30.8 ± 3.6 (349)  30.7 ± 3.6 (341)  30.7 ± 3.7 (353)  0.09 (−0.05, 0.24)  0.21  Waist/hip ratio  1.0 ± 0.1 (394)  1.0 ± 0.1 (373)  1.0 ± 0.1 (367)  1.0 ± 0.1 (356)  1.0 ± 0.1 (366)  1.0 ± 0.1 (394)  1.0 ± 0.1 (369)  1.0 ± 0.1 (349)  1.0 ± 0.1 (342)  1.0 ± 0.1 (353)  −0.002 (−0.006, 0.003)  0.46  Values are means ± standard number (number). Abbreviations: BMI, body mass index; CI, confidence interval. a Average over all observations, adjusting for balancing factors and baseline value. Positive values mean men in the testosterone arm increased more or decreased less than men in the placebo arm; negative values mean men in the placebo arm increased more or decreased less than men in the testosterone arm. View Large Lipids Serum concentrations of lipids (Table 3) were evaluated for all men and then separately for men who were either consistently taking or not taking lipid-lowering drugs during the 12 months of treatment. Levels at baseline were slightly lower in men in the testosterone arm (total cholesterol, 161.9 mg/dL; HDL cholesterol, 44.5 mg/dL; LDL cholesterol, 87.9 mg/dL) than in men in the placebo arm (total cholesterol, 167.8 mg/dL; HDL cholesterol, 45.5 mg/dL; LDL cholesterol, 91.8 mg/dL). Lipid levels decreased during the 12 months of treatment in both treatment arms. Adjusting for baseline levels and balancing factors, the men treated with testosterone had a reduction in total cholesterol that was 6.1 mg/dL greater than men treated with placebo (P < 0.001). Reductions in HDL cholesterol (adjusted difference, −2.0 mg/dL; P < 0.001) and in non‒HDL cholesterol (adjusted difference, −4.2; P = 0.005) were also greater in men treated with testosterone than in men treated with placebo. Change in LDL cholesterol was marginally greater in the testosterone arm; the adjusted difference in change was 2.3 mg/dL (P = 0.051). Reductions in triglyceride values were not significantly associated with treatment assignment. Table 3. Serum Concentrations of Lipids Assay  Testosterone   Placebo   Difference in Change Over Time (95% CI)a  P Value  Baseline (n)  Month 3 (n)  Month 12 (n)  Baseline (n)  Month 3 (n)  Month 12 (n)  Cholesterol, mg/dL  161.9 ± 37.1 (369)  153.7 ± 35.1 (367)  154.9 ± 32.3 (346)  167.8 ± 33.8 (369)  164.5 ± 36.5 (367)  164.6 ± 34.6 (333)  −6.1 (−8.9, −3.3)  <0.001  HDL cholesterol, mg/dL  44.5 ± 12.7 (369)  41.8 ± 12.2 (367)  43.1 ± 12.6 (346)  45.5 ± 14.4 (369)  44.8 ± 13.3 (367)  45.3 ± 13.1 (333)  −2.0 (−2.9, −1.0)  <0.001  Non‒HDL cholesterol, mg/dL  117.4 ± 37.2 (369)  111.9 ± 34.7 (367)  111.8 ± 31.9 (346)  122.2 ± 35.2 (369)  119.7 ± 37.1 (367)  119.3 ± 35.4 (333)  −4.2 (−7.1, −1.3)  0.005  LDL cholesterol, mg/dL  87.9 ± 28.9 (363)  84.0 ± 28.2 (360)  84.9 ± 27.7 (341)  91.8 ± 29.6 (360)  89.1 ± 30.5 (363)  89.7 ± 27.8 (325)  −2.3 (−4.6, 0.01)  0.051  Cholesterol/HDL ratio  3.9 ± 2.1 (369)  4.0 ± 1.5 (367)  3.9 ± 1.6 (346)  4.0 ± 1.4 (369)  4.0 ± 1.4 (367)  3.9 ± 1.4 (333)  0.02 (−0.1, 0.2)  0.81  Triglycerides, mg/dL  150.1 ± 149.3 (369)  145.6 ± 136.0 (367)  140.7 ± 142.6 (346)  153.4 ± 84.3 (369)  151.3 ± 81.2 (367)  145.1 ± 77.5 (333)  −4.0 (−14.7, 6.8)  0.47  Assay  Testosterone   Placebo   Difference in Change Over Time (95% CI)a  P Value  Baseline (n)  Month 3 (n)  Month 12 (n)  Baseline (n)  Month 3 (n)  Month 12 (n)  Cholesterol, mg/dL  161.9 ± 37.1 (369)  153.7 ± 35.1 (367)  154.9 ± 32.3 (346)  167.8 ± 33.8 (369)  164.5 ± 36.5 (367)  164.6 ± 34.6 (333)  −6.1 (−8.9, −3.3)  <0.001  HDL cholesterol, mg/dL  44.5 ± 12.7 (369)  41.8 ± 12.2 (367)  43.1 ± 12.6 (346)  45.5 ± 14.4 (369)  44.8 ± 13.3 (367)  45.3 ± 13.1 (333)  −2.0 (−2.9, −1.0)  <0.001  Non‒HDL cholesterol, mg/dL  117.4 ± 37.2 (369)  111.9 ± 34.7 (367)  111.8 ± 31.9 (346)  122.2 ± 35.2 (369)  119.7 ± 37.1 (367)  119.3 ± 35.4 (333)  −4.2 (−7.1, −1.3)  0.005  LDL cholesterol, mg/dL  87.9 ± 28.9 (363)  84.0 ± 28.2 (360)  84.9 ± 27.7 (341)  91.8 ± 29.6 (360)  89.1 ± 30.5 (363)  89.7 ± 27.8 (325)  −2.3 (−4.6, 0.01)  0.051  Cholesterol/HDL ratio  3.9 ± 2.1 (369)  4.0 ± 1.5 (367)  3.9 ± 1.6 (346)  4.0 ± 1.4 (369)  4.0 ± 1.4 (367)  3.9 ± 1.4 (333)  0.02 (−0.1, 0.2)  0.81  Triglycerides, mg/dL  150.1 ± 149.3 (369)  145.6 ± 136.0 (367)  140.7 ± 142.6 (346)  153.4 ± 84.3 (369)  151.3 ± 81.2 (367)  145.1 ± 77.5 (333)  −4.0 (−14.7, 6.8)  0.47  Values are means ± standard deviation and (number of participants). Abbreviation: CI, confidence interval. a Average over all observations, adjusting for balancing factors and baseline value. Positive values mean men in the testosterone arm increased more or decreased less than men in the placebo arm; negative values mean men in the placebo arm increased more or decreased less than men in the testosterone arm. View Large Eleven men in the testosterone arm and four in the placebo arm initiated lipid-lowering medication after baseline. To assess the effect of these medication changes, we performed an analysis excluding these 15 men; the results changed minimally. Markers of glucose metabolism We evaluated markers that reflect glucose metabolism (Table 4) in all men and separately in men who were not taking medications for diabetes during the trial. Mean levels were similar in the two treatment groups at baseline [fasting glucose, 114.4 vs 116.0 mg/dL; fasting insulin, 18.6 vs 18.1 μU/mL; homeostatic model assessment‒insulin resistance (HOMA-IR), 5.8 vs 5.9; and HbA1c, 6.3% vs 6.3% in the testosterone and placebo arms, respectively]. Changes from baseline in these markers were small in both groups, but some differences in the changes between treatment arms were statistically significant (glucose, 1.3 vs 2.2 mg/dL; adjusted difference, −1.5 mg/dL; P = 0.30; insulin, −1.8 vs −0.7 μU/mL; adjusted difference, −1.7 μU/mL; P = 0.02; HOMA-IR, 0.3 vs −0.2; adjusted difference, −0.6; P = 0.03; and HbA1c, 0.0% vs 0.1%; adjusted difference −0.07%; P = 0.09 for men in the testosterone group vs the placebo group, respectively). Evaluation of these markers in men not taking antidiabetic medications showed no statistically significant effect of testosterone. Table 4. Markers of Glucose Metabolism Assay  Testosterone   Placebo   Difference in Change Over Timea 
(95% CI)  P Value  Baseline (n)  Month 3 (n)  Month 12 (n)  Baseline (n)  Month 3 (n)  Month 12 (n)  Glucose, mg/dL  114.4 ± 28.2 (369)  113.6 ± 32.4 (367)  115.7 ± 30.9 (346)  116.0 ± 27.8 (369)  116.1 ± 29.1 (367)  118.2 ± 35.2 (333)  −1.5 (−4.3, 1.3)  0.30  Insulin, µU/mL  19.6 ± 19.0 (367)  17.3 ± 12.5 (365)  17.9 ± 13.6 (342)  17.5 ± 12.2 (364)  19.2 ± 14.8 (365)  19.3 ± 14.9 (330)  −1.7 (−3.1, −0.3)  0.02  HOMA-IRb  5.8 ± 6.3 (367)  5.1 ± 4.6 (365)  5.5 ± 6.4 (342)  5.8 ± 6.0 (364)  5.9 ± 6.2 (365)  5.6 ± 5.5 (330)  −0.6 (−1.2, −0.1)  0.03  HbA1c,c%  6.3 ± 0.8 (249)  —  6.3 ± 0.9 (250)  6.3 ± 0.8 (243)  —  6.4 ± 1.0 (242)  −0.07 (−0.2, 0.01)  0.09  Assay  Testosterone   Placebo   Difference in Change Over Timea 
(95% CI)  P Value  Baseline (n)  Month 3 (n)  Month 12 (n)  Baseline (n)  Month 3 (n)  Month 12 (n)  Glucose, mg/dL  114.4 ± 28.2 (369)  113.6 ± 32.4 (367)  115.7 ± 30.9 (346)  116.0 ± 27.8 (369)  116.1 ± 29.1 (367)  118.2 ± 35.2 (333)  −1.5 (−4.3, 1.3)  0.30  Insulin, µU/mL  19.6 ± 19.0 (367)  17.3 ± 12.5 (365)  17.9 ± 13.6 (342)  17.5 ± 12.2 (364)  19.2 ± 14.8 (365)  19.3 ± 14.9 (330)  −1.7 (−3.1, −0.3)  0.02  HOMA-IRb  5.8 ± 6.3 (367)  5.1 ± 4.6 (365)  5.5 ± 6.4 (342)  5.8 ± 6.0 (364)  5.9 ± 6.2 (365)  5.6 ± 5.5 (330)  −0.6 (−1.2, −0.1)  0.03  HbA1c,c%  6.3 ± 0.8 (249)  —  6.3 ± 0.9 (250)  6.3 ± 0.8 (243)  —  6.4 ± 1.0 (242)  −0.07 (−0.2, 0.01)  0.09  Values are means ± standard deviation and (number of participants). Abbreviations: CI, confidence interval; HOMA-IR, homeostatic model assessment of insulin resistance. a Average over all observations, adjusting for balancing factors and baseline value. Positive values mean men in the testosterone arm increased more or decreased less than men in the placebo arm; negative values mean men in the placebo arm increased more or decreased less than men in the testosterone arm. b HOMA-IR calculated as glucose × insulin/22.5. c Collection of blood for HbA1c did not begin until after the trial was under way, so the n is smaller for this parameter. View Large Other markers We also measured d-dimer as a marker of fibrolysis, CRP and IL-6 as markers of inflammation, and troponin as a marker of myocardial damage (Table 5). All showed similar mean baseline values (d-dimer, 0.7 vs 0.7 mg/L; CRP, 3.5 vs 3.5 mg/L; IL-6, 1.9 vs 2.0 pg/mL; troponin, 7.6 vs 9.1 ng/L in the testosterone and placebo groups, respectively). Mean changes from baseline were small and were similar between the testosterone and placebo groups (d-dimer, 0.1 vs 0.1 mg/L; adjusted difference, 0.01; P = 0.69; CRP, −0.7 vs −0.1 mg/L; adjusted difference, −0.6 mg/L; P = 0.11; IL-6, 0.9 vs 0.2 pg/mL; adjusted difference, 0.2 pg/mL; P = 0.67; and troponin, 2.4 vs 0.1 ng/mL; adjusted difference, 0.9 mg/L; P = 0.37). Table 5. Other Markers Assay  Testosterone   Placebo   Difference in Change Over Timea (95% CI)  P Value  Baseline (n)  Month 3 (n)  Month 12 (n)  Baseline (n)  Month 3 (n)  Month 12 (n)  d-dimer, mg/L  0.7 ± 0.6 (370)  0.8 ± 1.2 (367)  0.8 ± 0.6 (351)  0.7 ± 0.6 (367)  0.8 ± 0.7 (364)  0.8 ± 0.8 (333)  0.01 (−0.1, 0.1)  0.69  CRP, mg/L  3.5 ± 9.4 (363)  3.4 ± 6.2 (363)  2.8 ± 3.8 (347)  3.5 ± 5.6 (363)  3.9 ± 9.1 (362)  3.4 ± 7.4 (332)  −0.60 (−1.3, 0.1)  0.11  Il-6, pg/mL  1.9 ± 5.8 (372)  2.0 ± 1.9 (371)  2.8 ± 18.3 (352)  2.0 ± 2.4 (371)  2.2 ± 2.9 (367)  2.2 ± 3.0 (336)  0.2 (−0.6, 0.9)  0.67  Troponin, ng/mL  7.6 ± 7.4 317)  9.1 ± 9.7 (316)  10.0 ± 15.0 (262)  9.1 ± 18.3 (307)  9.4 ± 17.4 (327)  9.2 ± 19.1 (278)  0.9 (−1.1, 2.9)  0.37  Assay  Testosterone   Placebo   Difference in Change Over Timea (95% CI)  P Value  Baseline (n)  Month 3 (n)  Month 12 (n)  Baseline (n)  Month 3 (n)  Month 12 (n)  d-dimer, mg/L  0.7 ± 0.6 (370)  0.8 ± 1.2 (367)  0.8 ± 0.6 (351)  0.7 ± 0.6 (367)  0.8 ± 0.7 (364)  0.8 ± 0.8 (333)  0.01 (−0.1, 0.1)  0.69  CRP, mg/L  3.5 ± 9.4 (363)  3.4 ± 6.2 (363)  2.8 ± 3.8 (347)  3.5 ± 5.6 (363)  3.9 ± 9.1 (362)  3.4 ± 7.4 (332)  −0.60 (−1.3, 0.1)  0.11  Il-6, pg/mL  1.9 ± 5.8 (372)  2.0 ± 1.9 (371)  2.8 ± 18.3 (352)  2.0 ± 2.4 (371)  2.2 ± 2.9 (367)  2.2 ± 3.0 (336)  0.2 (−0.6, 0.9)  0.67  Troponin, ng/mL  7.6 ± 7.4 317)  9.1 ± 9.7 (316)  10.0 ± 15.0 (262)  9.1 ± 18.3 (307)  9.4 ± 17.4 (327)  9.2 ± 19.1 (278)  0.9 (−1.1, 2.9)  0.37  Values are means ± standard deviation and (number of participants). Abbreviation: CI, confidence interval. a Average over all observations, adjusting for balancing factors and baseline value. Positive values mean men in the testosterone arm increased more or decreased less than men in the placebo arm; negative values mean men in the placebo arm increased more or decreased less than men in the testosterone arm. View Large Because testosterone treatment was associated with a greater increase in coronary artery plaque volume in the 138 men who participated in the Cardiovascular Trial (11), we repeated all the analyses of the effects of testosterone in just the 138 men who participated in the Cardiovascular Trial. The results in these 138 men were similar to the results in all TTrials participants. Discussion In the TTrials, raising the serum testosterone concentrations of men ≥65 years of age who had low baseline testosterone values to normal levels for young men for 1 year did not affect weight, body mass index, or waist/hip ratio but slightly decreased serum concentrations of total, HDL, and LDL cholesterol. The total cholesterol/HDL cholesterol ratio was not altered. Testosterone treatment also slightly decreased markers of insulin resistance but did not change fasting glucose or HbA1c levels. Testosterone treatment did not appreciably change markers of inflammation, fibrinolysis, or myocardial damage. Prior trials of the effects of injectable testosterone esters on serum lipid levels in hypogonadal men have also demonstrated small reductions in serum total, HDL cholesterol, and LDL cholesterol levels (12). Meta-analyses of testosterone trials that included variable entry criteria for participants, routes of administration, and doses have shown inconsistent effects on cholesterol (8, 13). In a double-blind crossover study of injectable testosterone vs placebo in 24 hypogonadal men with type 2 diabetes, testosterone treatment was associated with improved insulin sensitivity and glycated hemoglobin levels (14), but meta-analyses have generally not reported an effect of testosterone on glucose metabolism (8). Several studies have shown no clear effects of testosterone treatment on various inflammatory markers (15–17). Compared with the effect of statin drugs on lowering LDL cholesterol, the effect of testosterone in this trial was quite small. Statin drugs, in doses used clinically, lower LDL cholesterol by 10 to 80 mg/dL (18) compared with the mean reduction of 2.3 mg/dL associated with testosterone treatment in this trial. Compared with the effect of statin drugs raising HDL cholesterol level, the effect of testosterone on lowering HDL cholesterol level is similar. Statin drugs, in doses used clinically, raise HDL cholesterol by 2 to 3 mg/dL (19), similar in magnitude to the reduction of 2.0 mg/dL associated with testosterone treatment in this trial. Ingestion of 17-alkylated androgens, which are abused by athletes, decreases HDL cholesterol much more than testosterone itself (20). The results presented here are important because of the many strengths of the TTrials, including the large number of participants, the placebo-controlled design, raising the median serum testosterone level from unequivocally low to midnormal for young men, and the excellent participant retention. One limitation of this trial is that the results apply only to older men with low testosterone. Another limitation is that all of the cardiovascular markers assessed were surrogates and not clinical outcomes. Yet another limitation is that we did not assess the function of the lipoproteins, such as the effect of HDL on cholesterol transport (21). The clinical significance of the decreases in cholesterol levels is uncertain because both LDL and HDL cholesterol levels fell, both to small degrees, and insulin and HOMA-IR levels fell but only slightly. In the 138 men in the TTrials who underwent computed tomography angiography at baseline and month 12, testosterone treatment was associated with a greater increase in noncalcified coronary artery plaque volume than placebo treatment, yet in all TTrials participants, a similar number of men (seven) in each treatment arm experienced major adverse cardiovascular events (10). A trial of a much larger number of men treated for a much longer time is necessary to determine whether testosterone treatment of hypogonadal men affects clinical cardiovascular risk. We concluded that raising the serum testosterone levels of men ≥65 years of age with low testosterone to normal levels for young men slightly decreased their serum cholesterol and insulin levels, but the clinical significance of these small decreases is unknown. Abbreviations: CRP C-reactive protein CV coefficient of variation HbA1c hemoglobin A1c HDL high-density lipoprotein HOMA-IR homeostatic model assessment‒insulin resistance IL interleukin LDL low-density lipoprotein TTrials Testosterone Trials. Acknowledgments Financial Support: The Testosterone Trials were supported by a grant from the National Institute on Aging, National Institutes of Health (U01 AG030644) (to P.J.S.), supplemented by funds from the National Heart, Lung and Blood Institute, National Institute of Neurologic Diseases and Stroke, and National Institute of Child Health and Human Development. AbbVie (formerly Solvay and Abbott Laboratories) generously provided funding, AndroGel, and placebo gel. UAB Diabetes Research and Training Center (DRCT), Grant DK-079626 from the National Institute for Diabetes, Digestive and Kidney Diseases, National Institutes of Health (to C.E.L.); funding for the Rancho Bernardo Study has been supported by National Institutes of Health/National Institute on Aging grants AG07181 and AG028507 and the National Institute of Diabetes and Digestive and Kidney Diseases, Grants DK31801 (to E.B.-C.), T32-DK007571 (to R.S.S.), and U01-AG030644 (main) and 5 R01 AG37679 (bone) (to J.A.C.). T.M.G. is the recipient of Academic Leadership Award K07AG043587 from the National Institute on Aging. The Yale Field Center is partially supported by the Claude D. Pepper Older Americans Independence Center (Grant P30AG021342). A.M.M. was supported by Department of Veterans Affairs Puget Sound Health Care System Grant U01-AG030644. Clinical Trial Information: ClinicalTrials.gov no. NCT00799617 (registered 1 December 2008). Disclosure Summary: E.R.M. reports grants from Clarus Pharmaceuticals and AbbVie. Outside the submitted work, S.S.E. reports grants from the National Institutes of Health (NIH) and from AbbVie, Inc, and during the conduct of the study, grants from AbbVie, Inc. Outside the submitted work, C.E.L. reports grants from the NIH and grants from AbbVie. During the conduct of the study, N.K.W. reports grants from Alnylam Pharmaceuticals, grants and personal fees from Gilead Sciences, grants from the NHLBI, grants from Pfizer, grants from the Society for Women's Health Research, personal fees from Amgen, personal fees from AstraZeneca, and personal fees from Merck. Outside the submitted work, M.J.B. reports grants from the NIH and during the conduct of the study, grants from General Electric. Outside the submitted work, E.B.-C. has nothing to disclose. R.S.S. reports grants from The Bone Trial of the Testosterone Trial during the conduct of the study, grants and other from Clarus, grants from Lipesene, and grants and other from Antares. Outside the submitted work, A.S.-S. reports grants from the National Institute on Aging and from AbbVie during the conduct of the study. S.B. reports grants from the NIA during the conduct of the study and grants and personal fees from AbbVie, grants and personal fees from Lilly, grants from Transition Therapeutics, and grants and personal fees from Regeneron outside the submitted work. In addition, S.B. has a patent free testosterone calculator pending and has equity interest in FPT, LLC. J.A.C. has nothing to disclose. J.P.C. has nothing to disclose. G.R.C. reports personal fees from AbbVie, Clarus Therapeutics, Endo Pharma, Ferring, Lilly, Merck, Pfizer, and Repros Therapeutics. Outside the submitted work, K.E.E. reports grants from the National Institute on Aging. During the conduct of the study, T.M.G. reports grants from the National Institute on Aging. During the course of the study, A.M.M. reports personal fees from AbbVie, Endo, Lilly, Lipocine, Clarus, and AYTU. Outside the submitted work, M.E.M. reports grants from the NIH, grants from Abbott Laboratories, and during the conduct of the study, personal fees from AbbVie (Abbott Laboratories), personal fees from Eli Lilly & Co., and personal fees from Pfizer. Outside the submitted work, X.H. has nothing to disclose. D.C. has nothing to disclose. P.J.S. reports grants from the National Institute on Aging and NIH and grants and nonfinancial support from AbbVie (formerly Solvay and Abbott Laboratories) during the conduct of the study. M.R.L., M.P., and P.E.P. have nothing to disclose. References 1. Finkle WD, Greenland S, Ridgeway GK, Adams JL, Frasco MA, Cook MB, Fraumeni JF, Jr, Hoover RN. Increased risk of non-fatal myocardial infarction following testosterone therapy prescription in men. PLoS One . 2014; 9( 1): e85805. Google Scholar CrossRef Search ADS PubMed  2. Vigen R, O’Donnell CI, Barón AE, Grunwald GK, Maddox TM, Bradley SM, Barqawi A, Woning G, Wierman ME, Plomondon ME, Rumsfeld JS, Ho PM. Association of testosterone therapy with mortality, myocardial infarction, and stroke in men with low testosterone levels. JAMA . 2013; 310( 17): 1829– 1836. Google Scholar CrossRef Search ADS PubMed  3. Baillargeon J, Urban RJ, Kuo YF, Ottenbacher KJ, Raji MA, Du F, Lin YL, Goodwin JS. Risk of myocardial infarction in older men receiving testosterone therapy. Ann Pharmacother . 2014; 48( 9): 1138– 1144. Google Scholar CrossRef Search ADS PubMed  4. Shores MM, Smith NL, Forsberg CW, Anawalt BD, Matsumoto AM. Testosterone treatment and mortality in men with low testosterone levels. J Clin Endocrinol Metab . 2012; 97( 6): 2050– 2058. Google Scholar CrossRef Search ADS PubMed  5. Basaria S, Coviello AD, Travison TG, Storer TW, Farwell WR, Jette AM, Eder R, Tennstedt S, Ulloor J, Zhang A, Choong K, Lakshman KM, Mazer NA, Miciek R, Krasnoff J, Elmi A, Knapp PE, Brooks B, Appleman E, Aggarwal S, Bhasin G, Hede-Brierley L, Bhatia A, Collins L, LeBrasseur N, Fiore LD, Bhasin S. Adverse events associated with testosterone administration. N Engl J Med . 2010; 363( 2): 109– 122. Google Scholar CrossRef Search ADS PubMed  6. Srinivas-Shankar U, Roberts SA, Connolly MJ, O’Connell MD, Adams JE, Oldham JA, Wu FC. Effects of testosterone on muscle strength, physical function, body composition, and quality of life in intermediate-frail and frail elderly men: a randomized, double-blind, placebo-controlled study. J Clin Endocrinol Metab . 2010; 95( 2): 639– 650. Google Scholar CrossRef Search ADS PubMed  7. Fernández-Balsells MM, Murad MH, Lane M, Lampropulos JF, Albuquerque F, Mullan RJ, Agrwal N, Elamin MB, Gallegos-Orozco JF, Wang AT, Erwin PJ, Bhasin S, Montori VM. Clinical review 1: adverse effects of testosterone therapy in adult men: a systematic review and meta-analysis. J Clin Endocrinol Metab . 2010; 95( 6): 2560– 2575. Google Scholar CrossRef Search ADS PubMed  8. Haddad RM, Kennedy CC, Caples SM, Tracz MJ, Boloña ER, Sideras K, Uraga MV, Erwin PJ, Montori VM. Testosterone and cardiovascular risk in men: a systematic review and meta-analysis of randomized placebo-controlled trials. Mayo Clin Proc . 2007; 82( 1): 29– 39. Google Scholar CrossRef Search ADS PubMed  9. Snyder PJ, Ellenberg SS, Cunningham GR, Matsumoto AM, Bhasin S, Barrett-Connor E, Gill TM, Farrar JT, Cella D, Rosen RC, Resnick SM, Swerdloff RS, Cauley JA, Cifelli D, Fluharty L, Pahor M, Ensrud KE, Lewis CE, Molitch ME, Crandall JP, Wang C, Budoff MJ, Wenger NK, Mohler ER, Bild DE, Cook NL, Keaveny TM, Kopperdahl DL, Lee D, Schwartz AV, Storer TW, Ershler WB, Roy CN, Raffel LJ, Romashkan S, Hadley E. The Testosterone Trials: seven coordinated trials of testosterone treatment in elderly men. Clin Trials . 2014; 11( 3): 362– 375. Google Scholar CrossRef Search ADS PubMed  10. Snyder PJ, Bhasin S, Cunningham GR, Matsumoto AM, Stephens-Shields AJ, Cauley JA, Gill TM, Barrett-Connor E, Swerdloff RS, Wang C, Ensrud KE, Lewis CE, Farrar JT, Cella D, Rosen RC, Pahor M, Crandall JP, Molitch ME, Cifelli D, Dougar D, Fluharty L, Resnick SM, Storer TW, Anton S, Basaria S, Diem SJ, Hou X, Mohler ER III, Parsons JK, Wenger NK, Zeldow B, Landis JR, Ellenberg SS; Testosterone Trials Investigators. Effects of testosterone treatment in older men. N Engl J Med . 2016; 374( 7): 611– 624. Google Scholar CrossRef Search ADS PubMed  11. Budoff MJ, Ellenberg SS, Lewis CE, Mohler ER III, Wenger NK, Bhasin S, Barrett-Connor E, Swerdloff RS, Stephens-Shields A, Cauley JA, Crandall JP, Cunningham GR, Ensrud KE, Gill TM, Matsumoto AM, Molitch ME, Nakanishi R, Nezarat N, Matsumoto S, Hou X, Basaria S, Diem SJ, Wang C, Cifelli D, Snyder PJ. Testosterone treatment and coronary artery plaque volume in older men with low testosterone. JAMA . 2017; 317( 7): 708– 716. Google Scholar CrossRef Search ADS PubMed  12. Whitsel EA, Boyko EJ, Matsumoto AM, Anawalt BD, Siscovick DS. Intramuscular testosterone esters and plasma lipids in hypogonadal men: a meta-analysis. Am J Med . 2001; 111( 4): 261– 269. Google Scholar CrossRef Search ADS PubMed  13. Isidori AM, Giannetta E, Greco EA, Gianfrilli D, Bonifacio V, Isidori A, Lenzi A, Fabbri A. Effects of testosterone on body composition, bone metabolism and serum lipid profile in middle-aged men: a meta-analysis. Clin Endocrinol (Oxf) . 2005; 63( 3): 280– 293. Google Scholar CrossRef Search ADS PubMed  14. Kapoor D, Goodwin E, Channer KS, Jones TH. Testosterone replacement therapy improves insulin resistance, glycaemic control, visceral adiposity and hypercholesterolaemia in hypogonadal men with type 2 diabetes. Eur J Endocrinol . 2006; 154( 6): 899– 906. Google Scholar CrossRef Search ADS PubMed  15. Ng MK, Liu PY, Williams AJ, Nakhla S, Ly LP, Handelsman DJ, Celermajer DS. Prospective study of effect of androgens on serum inflammatory markers in men. Arterioscler Thromb Vasc Biol . 2002; 22( 7): 1136– 1141. Google Scholar CrossRef Search ADS PubMed  16. Malkin CJ, Pugh PJ, Jones RD, Kapoor D, Channer KS, Jones TH. The effect of testosterone replacement on endogenous inflammatory cytokines and lipid profiles in hypogonadal men. J Clin Endocrinol Metab . 2004; 89( 7): 3313– 3318. Google Scholar CrossRef Search ADS PubMed  17. Nakhai-Pour HR, Grobbee DE, Emmelot-Vonk MH, Bots ML, Verhaar HJ, van der Schouw YT. Oral testosterone supplementation and chronic low-grade inflammation in elderly men: a 26-week randomized, placebo-controlled trial. Am Heart J . 2007; 154( 6): 1228.e1– e7. Google Scholar CrossRef Search ADS   18. Jones PH, Davidson MH, Stein EA, Bays HE, McKenney JM, Miller E, Cain VA, Blasetto JW; STELLAR Study Group. Comparison of the efficacy and safety of rosuvastatin versus atorvastatin, simvastatin, and pravastatin across doses (STELLAR* Trial). Am J Cardiol . 2003; 92( 2): 152– 160. Google Scholar CrossRef Search ADS PubMed  19. Barter PJ, Brandrup-Wognsen G, Palmer MK, Nicholls SJ. Effect of statins on HDL-C: a complex process unrelated to changes in LDL-C: analysis of the VOYAGER Database. J Lipid Res . 2010; 51( 6): 1546– 1553. Google Scholar CrossRef Search ADS PubMed  20. Thompson PD, Cullinane EM, Sady SP, Chenevert C, Saritelli AL, Sady MA, Herbert PN. Contrasting effects of testosterone and stanozolol on serum lipoprotein levels. JAMA . 1989; 261( 8): 1165– 1168. Google Scholar CrossRef Search ADS PubMed  21. Rader DJ, Hovingh GK. HDL and cardiovascular disease. Lancet . 2014; 384( 9943): 618– 625. Google Scholar CrossRef Search ADS PubMed  Copyright © 2018 Endocrine Society http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Clinical Endocrinology and Metabolism Oxford University Press

Loading next page...
 
/lp/ou_press/the-effect-of-testosterone-on-cardiovascular-biomarkers-in-the-KmwVz7fNQO
Publisher
Endocrine Society
Copyright
Copyright © 2018 Endocrine Society
ISSN
0021-972X
eISSN
1945-7197
D.O.I.
10.1210/jc.2017-02243
Publisher site
See Article on Publisher Site

Abstract

Abstract Context Studies of the possible cardiovascular risk of testosterone treatment are inconclusive. Objective To determine the effect of testosterone treatment on cardiovascular biomarkers in older men with low testosterone. Design Double-blind, placebo-controlled trial. Setting Twelve academic medical centers in the United States. Participants In all, 788 men ≥65 years old with an average of two serum testosterone levels <275 ng/dL who were enrolled in The Testosterone Trials. Intervention Testosterone gel, the dose adjusted to maintain the testosterone level in the normal range for young men, or placebo gel for 12 months. Main Outcome Measures Serum markers of cardiovascular risk, including lipids and markers of glucose metabolism, fibrinolysis, inflammation, and myocardial damage. Results Compared with placebo, testosterone treatment significantly decreased total cholesterol (adjusted mean difference, −6.1 mg/dL; P < 0.001), high-density lipoprotein cholesterol (adjusted mean difference, −2.0 mg/dL; P < 0.001), and low-density lipoprotein cholesterol (adjusted mean difference, −2.3 mg/dL; P = 0.051) from baseline to month 12. Testosterone also slightly but significantly decreased fasting insulin (adjusted mean difference, −1.7 µIU/mL; P = 0.02) and homeostatic model assessment‒insulin resistance (adjusted mean difference, −0.6; P = 0.03). Testosterone did not change triglycerides, d-dimer, C-reactive protein, interleukin 6, troponin, glucose, or hemoglobin A1c levels more than placebo. Conclusions and Relevance Testosterone treatment of 1 year in older men with low testosterone was associated with small reductions in cholesterol and insulin but not with other glucose markers, markers of inflammation or fibrinolysis, or troponin. The clinical importance of these findings is unclear and requires a larger trial of clinical outcomes. The effect of testosterone treatment on cardiovascular risk is uncertain. Some retrospective studies using electronic medical records have reported more cardiovascular adverse events in men taking testosterone than in men not taking it, but others have not (1–4). These studies all have the limitations of not being controlled for diagnosis or treatment. One clinical trial of testosterone in frail older men was stopped early because more cardiovascular adverse events occurred in men taking testosterone than in men taking placebo (5), but another similar trial reported few adverse cardiovascular events (6). Meta-analyses of clinical trials have generally not shown more adverse cardiovascular events in men taking testosterone than in men taking placebo, but none of the individual trials was designed prospectively to capture these events (7, 8). The Testosterone Trials (TTrials) were a group of seven coordinated trials involving 788 men to determine the efficacy of raising the serum testosterone levels of men ≥65 years of age to normal levels for young men for 1 year (9). Although the numbers of men who experienced major cardiovascular adverse events were similar in the two treatment arms in all men in the TTrials (10), testosterone treatment was associated with a greater increase in noncalcified coronary artery plaque volume by computed tomographic angiography in the 138 men who participated in the Cardiovascular Trial (11). If testosterone does affect cardiovascular risk, it might do so by altering any one of several cardiovascular risk factors, such as lipids, glucose metabolism, coagulation, and inflammation. We therefore measured several biomarkers of cardiovascular risk at baseline and after 3 and 12 months of treatment in all men participating in the TTrials. Methods Study design The TTrials were a coordinated group of seven double-blind placebo-controlled trials designed to evaluate the efficacy of testosterone treatment in men ≥65 years of age who had age-related low testosterone levels (9). To participate in the TTrials, a man had to qualify for at least one of the three main trials (Sexual Function, Physical Function, and Vitality). Those who qualified could also participate in any of the other trials if they met the respective entry criteria. The participants were allocated to receive testosterone or placebo gel for 1 year. This report describes the serum levels of cardiovascular biomarkers at baseline and months 3 and 12 in all men participating in the TTrials. The institutional review boards of the 12 participating sites approved the TTrials protocols. Before trial-related procedures were conducted, all participants provided written informed consent. An independent Data and Safety Monitoring Board oversaw participant safety and trial conduct. Participants The inclusion and exclusion criteria have been published (9). In brief, men were included who were ≥65 years of age, had serum testosterone levels that averaged <275 ng/dL in two morning samples, and had subjective and objective evidence of sexual dysfunction, physical dysfunction, and/or reduced vitality. Men were excluded if they were at moderate or high risk for prostate cancer; had a myocardial infarction within the previous 3 months; or had a blood pressure level >160 mm Hg systolic or 100 mm Hg diastolic, serum creatinine level >2.2 mg/dL, or a hemoglobin A1c (HbA1c) value >8.5%. Men who were taking medications to control blood pressure or serum lipid levels were not excluded. Testosterone treatment Men were allocated to receive either testosterone as a 1% gel in a pump bottle (testosterone gel, AndroGel; AbbVie, North Chicago, IL) or similar placebo gel in a double-blind fashion for 1 year. The initial dose of testosterone was 5 g a day. The dose was adjusted to keep the serum concentration within the normal range for young men on the basis of measurement in a central laboratory (Quest Clinical Trials, Valencia, CA) at months 1, 2, 3, 6, and 9. To maintain the blind, when the dose was changed in a man taking testosterone, the dose was also changed in a man taking placebo. Assessments Blood for cardiovascular biomarkers was drawn fasting in the morning at baseline and at months 3 and 12; serum was stored at −80°C. Biomarker assays were performed at the Laboratory for Clinical Biochemistry Research, University of Vermont, with the exception of the troponin I assay, which was performed at the University of Minnesota. Samples from the same participant were assayed in the same batch. Clinical variables were measured at baseline and months 3, 6, 9, and 12. Lipid assays Lipid assays included total cholesterol [interassay coefficient of variation (CV) range, 1.45% to 2.33%], high-density lipoprotein (HDL) cholesterol (interassay CV range, 1.69% to 2.26%), and triglycerides (interassay CV range, 1.95% to 2.57%) using enzymatic colorimetric assays (Cobas Integra 400; Roche Diagnostics, Indianapolis, IN). Low-density lipoprotein (LDL) cholesterol was calculated using the Friedewald formula when the triglyceride concentration was <400 mg/dL. Glucose, insulin, and HbA1c assays Glucose concentration was determined using a hexokinase method (Cobas Integra 400, Roche Diagnostics) (interassay CV range, 2.24% to 4.55%). Insulin was measured by electrochemiluminescence immunoassay (Elecsys 2010; Roche Diagnostics) (interassay CV range, 2.39% to 2.78%). HbA1c was measured in frozen whole blood samples by turbidimetric inhibition immunoassay (Tina-quant HgA1C Gen 2 Whole Blood application, Cobas Integra 400; Roche Diagnostics) (interassay CV range, 1.63% to 3.25%). Assays of markers of inflammation C-reactive protein (CRP) was measured using a high-sensitivity particle enhanced immunonephelometric assay (BN II nephelometer; Siemens, Inc., Deerfield, IL) (interassay CV range, 3.32% to 4.64%). Interleukin (IL)-6 was measured by electrochemiluminescence immunoassay (Meso Scale Diagnostics, Rockville, MD) (interassay CV range, 8.14% to 11.95%). d-dimer and troponin assays d -dimer was measured using an immunoturbidimetric assay (STA-R Evolution, Diagnostica Stago, Parsippany, NJ) (interassay CV range, 2.73% to 20.14%). Troponin I was measured using a high-sensitivity immunoassay (ARCHITECT STAT high-sensitive troponin I assay; Abbott Laboratories, Abbott Park, IL). Statistical analyses The effects of testosterone were assessed using random effects models for longitudinal data. The models included visit time as a categorical variable and a single main effect for treatment and were adjusted for baseline values of each biomarker and all balancing variables used in the allocation procedure: study site, indicator variables of participation in each primary efficacy trial, baseline testosterone concentration (≤ or > 200 ng/dL), age (≤ or > 75 years), use of antidepressants, and use of phosphodiesterase-5 inhibitors. All participants who had at least one postbaseline value were included in the intent-to-treat analysis. We performed additional analyses of lipid markers excluding men who were not taking lipid-lowering medications at baseline but initiated them during the study; we also performed separate analyses of metabolic markers excluding men taking antidiabetic medications. Significance was assessed through the two-sided Wald test and confidence interval for the treatment effect. The treatment effect denotes the average difference in response by treatment arm across all visits (baseline and months 3 and 12). No adjustments were made for multiple testing. Results Participants and clinical measures TTrials enrollment was 788 men at 12 sites. The mean age at baseline was 72 years. Relatively high percentages were obese and had comorbid conditions, such as diabetes and hypertension, but the two treatment arms were well balanced for these conditions and related medications (Table 1). Testosterone treatment increased the serum testosterone concentration from unequivocally low at baseline to midnormal for young men by month 3 and maintained it at that level through month 12 (10). Compared with placebo, testosterone treatment did not significantly change weight (adjusted difference, 0.28 kg; P = 0.18), body mass index (adjusted difference, 0.09 kg/m2; P = 0.21), or waist/hip ratio (adjusted difference, 0.002; P = 0.46) (Table 2). Table 1. Characteristics of Participants at Baseline Characteristic  Treatment   Testosterone (n = 394)  Placebo (n = 394)  Demographics       Age, y  72 ± 5.7  72 ± 5.8   Height, cm  175 ± 7.1  175 ± 7.0   Weight, kg  95 ± 13.1  95 ± 14.0   BMI, kg/m2  31 ± 3.6  31 ± 3.5   BMI >30 kg/m2 (%)  251 (63.7%)  246 (62.4%)   Waist/hip ratio  1.0 ± 0.1  1.0 ± 0.1  Concomitant conditions       Diabetes, %  148 (37.6%)  144 (36.5%)   Hypertension, %  286 (72.6%)  279 (70.8%)   History of myocardial infarction  53 (13.5%)  63 (16.0%)   History of stroke  16 (4.1%)  17 (4.3%)  Medications       Antidiabetics  130 (33.0%)  131 (33.2%)   Lipid-lowering drugs  274 (69.5%)  273 (69.3%)  Characteristic  Treatment   Testosterone (n = 394)  Placebo (n = 394)  Demographics       Age, y  72 ± 5.7  72 ± 5.8   Height, cm  175 ± 7.1  175 ± 7.0   Weight, kg  95 ± 13.1  95 ± 14.0   BMI, kg/m2  31 ± 3.6  31 ± 3.5   BMI >30 kg/m2 (%)  251 (63.7%)  246 (62.4%)   Waist/hip ratio  1.0 ± 0.1  1.0 ± 0.1  Concomitant conditions       Diabetes, %  148 (37.6%)  144 (36.5%)   Hypertension, %  286 (72.6%)  279 (70.8%)   History of myocardial infarction  53 (13.5%)  63 (16.0%)   History of stroke  16 (4.1%)  17 (4.3%)  Medications       Antidiabetics  130 (33.0%)  131 (33.2%)   Lipid-lowering drugs  274 (69.5%)  273 (69.3%)  Values are mean ± standard deviation or no. (%). Abbreviation: BMI, body mass index. View Large Table 2. Clinical Measures Measure  Testosterone   Placebo   Difference in Change Over Timea (95% CI)  P Value  Baseline (n)  Month 3 (n)  Month 6 (n)  Month 9 (n)  Month 12 (n)  Baseline (n)  Month 3 (n)  Month 6 (n)  Month 9 (n)  Month 12 (n)  Weight, kg  94.8 ± 13.1 (394)  95.4 ± 12.9 (374)  94.6 ± 13.1 (367)  94.6 ± 12.9 (356)  94.1 ± 13.3 (367)  94.8 ± 14.0 (394)  94.7 ± 14.0 (371)  94.1 ± 14.1 (349)  93.5 ± 14.0 (341)  93.4 ± 14.1 (353)  0.28 (−0.13, 0.69)  0.18  BMI, kg/m2  31.0 ± 3.6 (394)  31.2 ± 3.6 (374)  30.9 ± 3.6 (367)  30.9 ± 3.6 (356)  30.8 ± 3.6 (367)  31.0 ± 3.6 (394)  30.9 ± 3.5 (371)  30.8 ± 3.6 (349)  30.7 ± 3.6 (341)  30.7 ± 3.7 (353)  0.09 (−0.05, 0.24)  0.21  Waist/hip ratio  1.0 ± 0.1 (394)  1.0 ± 0.1 (373)  1.0 ± 0.1 (367)  1.0 ± 0.1 (356)  1.0 ± 0.1 (366)  1.0 ± 0.1 (394)  1.0 ± 0.1 (369)  1.0 ± 0.1 (349)  1.0 ± 0.1 (342)  1.0 ± 0.1 (353)  −0.002 (−0.006, 0.003)  0.46  Measure  Testosterone   Placebo   Difference in Change Over Timea (95% CI)  P Value  Baseline (n)  Month 3 (n)  Month 6 (n)  Month 9 (n)  Month 12 (n)  Baseline (n)  Month 3 (n)  Month 6 (n)  Month 9 (n)  Month 12 (n)  Weight, kg  94.8 ± 13.1 (394)  95.4 ± 12.9 (374)  94.6 ± 13.1 (367)  94.6 ± 12.9 (356)  94.1 ± 13.3 (367)  94.8 ± 14.0 (394)  94.7 ± 14.0 (371)  94.1 ± 14.1 (349)  93.5 ± 14.0 (341)  93.4 ± 14.1 (353)  0.28 (−0.13, 0.69)  0.18  BMI, kg/m2  31.0 ± 3.6 (394)  31.2 ± 3.6 (374)  30.9 ± 3.6 (367)  30.9 ± 3.6 (356)  30.8 ± 3.6 (367)  31.0 ± 3.6 (394)  30.9 ± 3.5 (371)  30.8 ± 3.6 (349)  30.7 ± 3.6 (341)  30.7 ± 3.7 (353)  0.09 (−0.05, 0.24)  0.21  Waist/hip ratio  1.0 ± 0.1 (394)  1.0 ± 0.1 (373)  1.0 ± 0.1 (367)  1.0 ± 0.1 (356)  1.0 ± 0.1 (366)  1.0 ± 0.1 (394)  1.0 ± 0.1 (369)  1.0 ± 0.1 (349)  1.0 ± 0.1 (342)  1.0 ± 0.1 (353)  −0.002 (−0.006, 0.003)  0.46  Values are means ± standard number (number). Abbreviations: BMI, body mass index; CI, confidence interval. a Average over all observations, adjusting for balancing factors and baseline value. Positive values mean men in the testosterone arm increased more or decreased less than men in the placebo arm; negative values mean men in the placebo arm increased more or decreased less than men in the testosterone arm. View Large Lipids Serum concentrations of lipids (Table 3) were evaluated for all men and then separately for men who were either consistently taking or not taking lipid-lowering drugs during the 12 months of treatment. Levels at baseline were slightly lower in men in the testosterone arm (total cholesterol, 161.9 mg/dL; HDL cholesterol, 44.5 mg/dL; LDL cholesterol, 87.9 mg/dL) than in men in the placebo arm (total cholesterol, 167.8 mg/dL; HDL cholesterol, 45.5 mg/dL; LDL cholesterol, 91.8 mg/dL). Lipid levels decreased during the 12 months of treatment in both treatment arms. Adjusting for baseline levels and balancing factors, the men treated with testosterone had a reduction in total cholesterol that was 6.1 mg/dL greater than men treated with placebo (P < 0.001). Reductions in HDL cholesterol (adjusted difference, −2.0 mg/dL; P < 0.001) and in non‒HDL cholesterol (adjusted difference, −4.2; P = 0.005) were also greater in men treated with testosterone than in men treated with placebo. Change in LDL cholesterol was marginally greater in the testosterone arm; the adjusted difference in change was 2.3 mg/dL (P = 0.051). Reductions in triglyceride values were not significantly associated with treatment assignment. Table 3. Serum Concentrations of Lipids Assay  Testosterone   Placebo   Difference in Change Over Time (95% CI)a  P Value  Baseline (n)  Month 3 (n)  Month 12 (n)  Baseline (n)  Month 3 (n)  Month 12 (n)  Cholesterol, mg/dL  161.9 ± 37.1 (369)  153.7 ± 35.1 (367)  154.9 ± 32.3 (346)  167.8 ± 33.8 (369)  164.5 ± 36.5 (367)  164.6 ± 34.6 (333)  −6.1 (−8.9, −3.3)  <0.001  HDL cholesterol, mg/dL  44.5 ± 12.7 (369)  41.8 ± 12.2 (367)  43.1 ± 12.6 (346)  45.5 ± 14.4 (369)  44.8 ± 13.3 (367)  45.3 ± 13.1 (333)  −2.0 (−2.9, −1.0)  <0.001  Non‒HDL cholesterol, mg/dL  117.4 ± 37.2 (369)  111.9 ± 34.7 (367)  111.8 ± 31.9 (346)  122.2 ± 35.2 (369)  119.7 ± 37.1 (367)  119.3 ± 35.4 (333)  −4.2 (−7.1, −1.3)  0.005  LDL cholesterol, mg/dL  87.9 ± 28.9 (363)  84.0 ± 28.2 (360)  84.9 ± 27.7 (341)  91.8 ± 29.6 (360)  89.1 ± 30.5 (363)  89.7 ± 27.8 (325)  −2.3 (−4.6, 0.01)  0.051  Cholesterol/HDL ratio  3.9 ± 2.1 (369)  4.0 ± 1.5 (367)  3.9 ± 1.6 (346)  4.0 ± 1.4 (369)  4.0 ± 1.4 (367)  3.9 ± 1.4 (333)  0.02 (−0.1, 0.2)  0.81  Triglycerides, mg/dL  150.1 ± 149.3 (369)  145.6 ± 136.0 (367)  140.7 ± 142.6 (346)  153.4 ± 84.3 (369)  151.3 ± 81.2 (367)  145.1 ± 77.5 (333)  −4.0 (−14.7, 6.8)  0.47  Assay  Testosterone   Placebo   Difference in Change Over Time (95% CI)a  P Value  Baseline (n)  Month 3 (n)  Month 12 (n)  Baseline (n)  Month 3 (n)  Month 12 (n)  Cholesterol, mg/dL  161.9 ± 37.1 (369)  153.7 ± 35.1 (367)  154.9 ± 32.3 (346)  167.8 ± 33.8 (369)  164.5 ± 36.5 (367)  164.6 ± 34.6 (333)  −6.1 (−8.9, −3.3)  <0.001  HDL cholesterol, mg/dL  44.5 ± 12.7 (369)  41.8 ± 12.2 (367)  43.1 ± 12.6 (346)  45.5 ± 14.4 (369)  44.8 ± 13.3 (367)  45.3 ± 13.1 (333)  −2.0 (−2.9, −1.0)  <0.001  Non‒HDL cholesterol, mg/dL  117.4 ± 37.2 (369)  111.9 ± 34.7 (367)  111.8 ± 31.9 (346)  122.2 ± 35.2 (369)  119.7 ± 37.1 (367)  119.3 ± 35.4 (333)  −4.2 (−7.1, −1.3)  0.005  LDL cholesterol, mg/dL  87.9 ± 28.9 (363)  84.0 ± 28.2 (360)  84.9 ± 27.7 (341)  91.8 ± 29.6 (360)  89.1 ± 30.5 (363)  89.7 ± 27.8 (325)  −2.3 (−4.6, 0.01)  0.051  Cholesterol/HDL ratio  3.9 ± 2.1 (369)  4.0 ± 1.5 (367)  3.9 ± 1.6 (346)  4.0 ± 1.4 (369)  4.0 ± 1.4 (367)  3.9 ± 1.4 (333)  0.02 (−0.1, 0.2)  0.81  Triglycerides, mg/dL  150.1 ± 149.3 (369)  145.6 ± 136.0 (367)  140.7 ± 142.6 (346)  153.4 ± 84.3 (369)  151.3 ± 81.2 (367)  145.1 ± 77.5 (333)  −4.0 (−14.7, 6.8)  0.47  Values are means ± standard deviation and (number of participants). Abbreviation: CI, confidence interval. a Average over all observations, adjusting for balancing factors and baseline value. Positive values mean men in the testosterone arm increased more or decreased less than men in the placebo arm; negative values mean men in the placebo arm increased more or decreased less than men in the testosterone arm. View Large Eleven men in the testosterone arm and four in the placebo arm initiated lipid-lowering medication after baseline. To assess the effect of these medication changes, we performed an analysis excluding these 15 men; the results changed minimally. Markers of glucose metabolism We evaluated markers that reflect glucose metabolism (Table 4) in all men and separately in men who were not taking medications for diabetes during the trial. Mean levels were similar in the two treatment groups at baseline [fasting glucose, 114.4 vs 116.0 mg/dL; fasting insulin, 18.6 vs 18.1 μU/mL; homeostatic model assessment‒insulin resistance (HOMA-IR), 5.8 vs 5.9; and HbA1c, 6.3% vs 6.3% in the testosterone and placebo arms, respectively]. Changes from baseline in these markers were small in both groups, but some differences in the changes between treatment arms were statistically significant (glucose, 1.3 vs 2.2 mg/dL; adjusted difference, −1.5 mg/dL; P = 0.30; insulin, −1.8 vs −0.7 μU/mL; adjusted difference, −1.7 μU/mL; P = 0.02; HOMA-IR, 0.3 vs −0.2; adjusted difference, −0.6; P = 0.03; and HbA1c, 0.0% vs 0.1%; adjusted difference −0.07%; P = 0.09 for men in the testosterone group vs the placebo group, respectively). Evaluation of these markers in men not taking antidiabetic medications showed no statistically significant effect of testosterone. Table 4. Markers of Glucose Metabolism Assay  Testosterone   Placebo   Difference in Change Over Timea 
(95% CI)  P Value  Baseline (n)  Month 3 (n)  Month 12 (n)  Baseline (n)  Month 3 (n)  Month 12 (n)  Glucose, mg/dL  114.4 ± 28.2 (369)  113.6 ± 32.4 (367)  115.7 ± 30.9 (346)  116.0 ± 27.8 (369)  116.1 ± 29.1 (367)  118.2 ± 35.2 (333)  −1.5 (−4.3, 1.3)  0.30  Insulin, µU/mL  19.6 ± 19.0 (367)  17.3 ± 12.5 (365)  17.9 ± 13.6 (342)  17.5 ± 12.2 (364)  19.2 ± 14.8 (365)  19.3 ± 14.9 (330)  −1.7 (−3.1, −0.3)  0.02  HOMA-IRb  5.8 ± 6.3 (367)  5.1 ± 4.6 (365)  5.5 ± 6.4 (342)  5.8 ± 6.0 (364)  5.9 ± 6.2 (365)  5.6 ± 5.5 (330)  −0.6 (−1.2, −0.1)  0.03  HbA1c,c%  6.3 ± 0.8 (249)  —  6.3 ± 0.9 (250)  6.3 ± 0.8 (243)  —  6.4 ± 1.0 (242)  −0.07 (−0.2, 0.01)  0.09  Assay  Testosterone   Placebo   Difference in Change Over Timea 
(95% CI)  P Value  Baseline (n)  Month 3 (n)  Month 12 (n)  Baseline (n)  Month 3 (n)  Month 12 (n)  Glucose, mg/dL  114.4 ± 28.2 (369)  113.6 ± 32.4 (367)  115.7 ± 30.9 (346)  116.0 ± 27.8 (369)  116.1 ± 29.1 (367)  118.2 ± 35.2 (333)  −1.5 (−4.3, 1.3)  0.30  Insulin, µU/mL  19.6 ± 19.0 (367)  17.3 ± 12.5 (365)  17.9 ± 13.6 (342)  17.5 ± 12.2 (364)  19.2 ± 14.8 (365)  19.3 ± 14.9 (330)  −1.7 (−3.1, −0.3)  0.02  HOMA-IRb  5.8 ± 6.3 (367)  5.1 ± 4.6 (365)  5.5 ± 6.4 (342)  5.8 ± 6.0 (364)  5.9 ± 6.2 (365)  5.6 ± 5.5 (330)  −0.6 (−1.2, −0.1)  0.03  HbA1c,c%  6.3 ± 0.8 (249)  —  6.3 ± 0.9 (250)  6.3 ± 0.8 (243)  —  6.4 ± 1.0 (242)  −0.07 (−0.2, 0.01)  0.09  Values are means ± standard deviation and (number of participants). Abbreviations: CI, confidence interval; HOMA-IR, homeostatic model assessment of insulin resistance. a Average over all observations, adjusting for balancing factors and baseline value. Positive values mean men in the testosterone arm increased more or decreased less than men in the placebo arm; negative values mean men in the placebo arm increased more or decreased less than men in the testosterone arm. b HOMA-IR calculated as glucose × insulin/22.5. c Collection of blood for HbA1c did not begin until after the trial was under way, so the n is smaller for this parameter. View Large Other markers We also measured d-dimer as a marker of fibrolysis, CRP and IL-6 as markers of inflammation, and troponin as a marker of myocardial damage (Table 5). All showed similar mean baseline values (d-dimer, 0.7 vs 0.7 mg/L; CRP, 3.5 vs 3.5 mg/L; IL-6, 1.9 vs 2.0 pg/mL; troponin, 7.6 vs 9.1 ng/L in the testosterone and placebo groups, respectively). Mean changes from baseline were small and were similar between the testosterone and placebo groups (d-dimer, 0.1 vs 0.1 mg/L; adjusted difference, 0.01; P = 0.69; CRP, −0.7 vs −0.1 mg/L; adjusted difference, −0.6 mg/L; P = 0.11; IL-6, 0.9 vs 0.2 pg/mL; adjusted difference, 0.2 pg/mL; P = 0.67; and troponin, 2.4 vs 0.1 ng/mL; adjusted difference, 0.9 mg/L; P = 0.37). Table 5. Other Markers Assay  Testosterone   Placebo   Difference in Change Over Timea (95% CI)  P Value  Baseline (n)  Month 3 (n)  Month 12 (n)  Baseline (n)  Month 3 (n)  Month 12 (n)  d-dimer, mg/L  0.7 ± 0.6 (370)  0.8 ± 1.2 (367)  0.8 ± 0.6 (351)  0.7 ± 0.6 (367)  0.8 ± 0.7 (364)  0.8 ± 0.8 (333)  0.01 (−0.1, 0.1)  0.69  CRP, mg/L  3.5 ± 9.4 (363)  3.4 ± 6.2 (363)  2.8 ± 3.8 (347)  3.5 ± 5.6 (363)  3.9 ± 9.1 (362)  3.4 ± 7.4 (332)  −0.60 (−1.3, 0.1)  0.11  Il-6, pg/mL  1.9 ± 5.8 (372)  2.0 ± 1.9 (371)  2.8 ± 18.3 (352)  2.0 ± 2.4 (371)  2.2 ± 2.9 (367)  2.2 ± 3.0 (336)  0.2 (−0.6, 0.9)  0.67  Troponin, ng/mL  7.6 ± 7.4 317)  9.1 ± 9.7 (316)  10.0 ± 15.0 (262)  9.1 ± 18.3 (307)  9.4 ± 17.4 (327)  9.2 ± 19.1 (278)  0.9 (−1.1, 2.9)  0.37  Assay  Testosterone   Placebo   Difference in Change Over Timea (95% CI)  P Value  Baseline (n)  Month 3 (n)  Month 12 (n)  Baseline (n)  Month 3 (n)  Month 12 (n)  d-dimer, mg/L  0.7 ± 0.6 (370)  0.8 ± 1.2 (367)  0.8 ± 0.6 (351)  0.7 ± 0.6 (367)  0.8 ± 0.7 (364)  0.8 ± 0.8 (333)  0.01 (−0.1, 0.1)  0.69  CRP, mg/L  3.5 ± 9.4 (363)  3.4 ± 6.2 (363)  2.8 ± 3.8 (347)  3.5 ± 5.6 (363)  3.9 ± 9.1 (362)  3.4 ± 7.4 (332)  −0.60 (−1.3, 0.1)  0.11  Il-6, pg/mL  1.9 ± 5.8 (372)  2.0 ± 1.9 (371)  2.8 ± 18.3 (352)  2.0 ± 2.4 (371)  2.2 ± 2.9 (367)  2.2 ± 3.0 (336)  0.2 (−0.6, 0.9)  0.67  Troponin, ng/mL  7.6 ± 7.4 317)  9.1 ± 9.7 (316)  10.0 ± 15.0 (262)  9.1 ± 18.3 (307)  9.4 ± 17.4 (327)  9.2 ± 19.1 (278)  0.9 (−1.1, 2.9)  0.37  Values are means ± standard deviation and (number of participants). Abbreviation: CI, confidence interval. a Average over all observations, adjusting for balancing factors and baseline value. Positive values mean men in the testosterone arm increased more or decreased less than men in the placebo arm; negative values mean men in the placebo arm increased more or decreased less than men in the testosterone arm. View Large Because testosterone treatment was associated with a greater increase in coronary artery plaque volume in the 138 men who participated in the Cardiovascular Trial (11), we repeated all the analyses of the effects of testosterone in just the 138 men who participated in the Cardiovascular Trial. The results in these 138 men were similar to the results in all TTrials participants. Discussion In the TTrials, raising the serum testosterone concentrations of men ≥65 years of age who had low baseline testosterone values to normal levels for young men for 1 year did not affect weight, body mass index, or waist/hip ratio but slightly decreased serum concentrations of total, HDL, and LDL cholesterol. The total cholesterol/HDL cholesterol ratio was not altered. Testosterone treatment also slightly decreased markers of insulin resistance but did not change fasting glucose or HbA1c levels. Testosterone treatment did not appreciably change markers of inflammation, fibrinolysis, or myocardial damage. Prior trials of the effects of injectable testosterone esters on serum lipid levels in hypogonadal men have also demonstrated small reductions in serum total, HDL cholesterol, and LDL cholesterol levels (12). Meta-analyses of testosterone trials that included variable entry criteria for participants, routes of administration, and doses have shown inconsistent effects on cholesterol (8, 13). In a double-blind crossover study of injectable testosterone vs placebo in 24 hypogonadal men with type 2 diabetes, testosterone treatment was associated with improved insulin sensitivity and glycated hemoglobin levels (14), but meta-analyses have generally not reported an effect of testosterone on glucose metabolism (8). Several studies have shown no clear effects of testosterone treatment on various inflammatory markers (15–17). Compared with the effect of statin drugs on lowering LDL cholesterol, the effect of testosterone in this trial was quite small. Statin drugs, in doses used clinically, lower LDL cholesterol by 10 to 80 mg/dL (18) compared with the mean reduction of 2.3 mg/dL associated with testosterone treatment in this trial. Compared with the effect of statin drugs raising HDL cholesterol level, the effect of testosterone on lowering HDL cholesterol level is similar. Statin drugs, in doses used clinically, raise HDL cholesterol by 2 to 3 mg/dL (19), similar in magnitude to the reduction of 2.0 mg/dL associated with testosterone treatment in this trial. Ingestion of 17-alkylated androgens, which are abused by athletes, decreases HDL cholesterol much more than testosterone itself (20). The results presented here are important because of the many strengths of the TTrials, including the large number of participants, the placebo-controlled design, raising the median serum testosterone level from unequivocally low to midnormal for young men, and the excellent participant retention. One limitation of this trial is that the results apply only to older men with low testosterone. Another limitation is that all of the cardiovascular markers assessed were surrogates and not clinical outcomes. Yet another limitation is that we did not assess the function of the lipoproteins, such as the effect of HDL on cholesterol transport (21). The clinical significance of the decreases in cholesterol levels is uncertain because both LDL and HDL cholesterol levels fell, both to small degrees, and insulin and HOMA-IR levels fell but only slightly. In the 138 men in the TTrials who underwent computed tomography angiography at baseline and month 12, testosterone treatment was associated with a greater increase in noncalcified coronary artery plaque volume than placebo treatment, yet in all TTrials participants, a similar number of men (seven) in each treatment arm experienced major adverse cardiovascular events (10). A trial of a much larger number of men treated for a much longer time is necessary to determine whether testosterone treatment of hypogonadal men affects clinical cardiovascular risk. We concluded that raising the serum testosterone levels of men ≥65 years of age with low testosterone to normal levels for young men slightly decreased their serum cholesterol and insulin levels, but the clinical significance of these small decreases is unknown. Abbreviations: CRP C-reactive protein CV coefficient of variation HbA1c hemoglobin A1c HDL high-density lipoprotein HOMA-IR homeostatic model assessment‒insulin resistance IL interleukin LDL low-density lipoprotein TTrials Testosterone Trials. Acknowledgments Financial Support: The Testosterone Trials were supported by a grant from the National Institute on Aging, National Institutes of Health (U01 AG030644) (to P.J.S.), supplemented by funds from the National Heart, Lung and Blood Institute, National Institute of Neurologic Diseases and Stroke, and National Institute of Child Health and Human Development. AbbVie (formerly Solvay and Abbott Laboratories) generously provided funding, AndroGel, and placebo gel. UAB Diabetes Research and Training Center (DRCT), Grant DK-079626 from the National Institute for Diabetes, Digestive and Kidney Diseases, National Institutes of Health (to C.E.L.); funding for the Rancho Bernardo Study has been supported by National Institutes of Health/National Institute on Aging grants AG07181 and AG028507 and the National Institute of Diabetes and Digestive and Kidney Diseases, Grants DK31801 (to E.B.-C.), T32-DK007571 (to R.S.S.), and U01-AG030644 (main) and 5 R01 AG37679 (bone) (to J.A.C.). T.M.G. is the recipient of Academic Leadership Award K07AG043587 from the National Institute on Aging. The Yale Field Center is partially supported by the Claude D. Pepper Older Americans Independence Center (Grant P30AG021342). A.M.M. was supported by Department of Veterans Affairs Puget Sound Health Care System Grant U01-AG030644. Clinical Trial Information: ClinicalTrials.gov no. NCT00799617 (registered 1 December 2008). Disclosure Summary: E.R.M. reports grants from Clarus Pharmaceuticals and AbbVie. Outside the submitted work, S.S.E. reports grants from the National Institutes of Health (NIH) and from AbbVie, Inc, and during the conduct of the study, grants from AbbVie, Inc. Outside the submitted work, C.E.L. reports grants from the NIH and grants from AbbVie. During the conduct of the study, N.K.W. reports grants from Alnylam Pharmaceuticals, grants and personal fees from Gilead Sciences, grants from the NHLBI, grants from Pfizer, grants from the Society for Women's Health Research, personal fees from Amgen, personal fees from AstraZeneca, and personal fees from Merck. Outside the submitted work, M.J.B. reports grants from the NIH and during the conduct of the study, grants from General Electric. Outside the submitted work, E.B.-C. has nothing to disclose. R.S.S. reports grants from The Bone Trial of the Testosterone Trial during the conduct of the study, grants and other from Clarus, grants from Lipesene, and grants and other from Antares. Outside the submitted work, A.S.-S. reports grants from the National Institute on Aging and from AbbVie during the conduct of the study. S.B. reports grants from the NIA during the conduct of the study and grants and personal fees from AbbVie, grants and personal fees from Lilly, grants from Transition Therapeutics, and grants and personal fees from Regeneron outside the submitted work. In addition, S.B. has a patent free testosterone calculator pending and has equity interest in FPT, LLC. J.A.C. has nothing to disclose. J.P.C. has nothing to disclose. G.R.C. reports personal fees from AbbVie, Clarus Therapeutics, Endo Pharma, Ferring, Lilly, Merck, Pfizer, and Repros Therapeutics. Outside the submitted work, K.E.E. reports grants from the National Institute on Aging. During the conduct of the study, T.M.G. reports grants from the National Institute on Aging. During the course of the study, A.M.M. reports personal fees from AbbVie, Endo, Lilly, Lipocine, Clarus, and AYTU. Outside the submitted work, M.E.M. reports grants from the NIH, grants from Abbott Laboratories, and during the conduct of the study, personal fees from AbbVie (Abbott Laboratories), personal fees from Eli Lilly & Co., and personal fees from Pfizer. Outside the submitted work, X.H. has nothing to disclose. D.C. has nothing to disclose. P.J.S. reports grants from the National Institute on Aging and NIH and grants and nonfinancial support from AbbVie (formerly Solvay and Abbott Laboratories) during the conduct of the study. M.R.L., M.P., and P.E.P. have nothing to disclose. References 1. Finkle WD, Greenland S, Ridgeway GK, Adams JL, Frasco MA, Cook MB, Fraumeni JF, Jr, Hoover RN. Increased risk of non-fatal myocardial infarction following testosterone therapy prescription in men. PLoS One . 2014; 9( 1): e85805. Google Scholar CrossRef Search ADS PubMed  2. Vigen R, O’Donnell CI, Barón AE, Grunwald GK, Maddox TM, Bradley SM, Barqawi A, Woning G, Wierman ME, Plomondon ME, Rumsfeld JS, Ho PM. Association of testosterone therapy with mortality, myocardial infarction, and stroke in men with low testosterone levels. JAMA . 2013; 310( 17): 1829– 1836. Google Scholar CrossRef Search ADS PubMed  3. Baillargeon J, Urban RJ, Kuo YF, Ottenbacher KJ, Raji MA, Du F, Lin YL, Goodwin JS. Risk of myocardial infarction in older men receiving testosterone therapy. Ann Pharmacother . 2014; 48( 9): 1138– 1144. Google Scholar CrossRef Search ADS PubMed  4. Shores MM, Smith NL, Forsberg CW, Anawalt BD, Matsumoto AM. Testosterone treatment and mortality in men with low testosterone levels. J Clin Endocrinol Metab . 2012; 97( 6): 2050– 2058. Google Scholar CrossRef Search ADS PubMed  5. Basaria S, Coviello AD, Travison TG, Storer TW, Farwell WR, Jette AM, Eder R, Tennstedt S, Ulloor J, Zhang A, Choong K, Lakshman KM, Mazer NA, Miciek R, Krasnoff J, Elmi A, Knapp PE, Brooks B, Appleman E, Aggarwal S, Bhasin G, Hede-Brierley L, Bhatia A, Collins L, LeBrasseur N, Fiore LD, Bhasin S. Adverse events associated with testosterone administration. N Engl J Med . 2010; 363( 2): 109– 122. Google Scholar CrossRef Search ADS PubMed  6. Srinivas-Shankar U, Roberts SA, Connolly MJ, O’Connell MD, Adams JE, Oldham JA, Wu FC. Effects of testosterone on muscle strength, physical function, body composition, and quality of life in intermediate-frail and frail elderly men: a randomized, double-blind, placebo-controlled study. J Clin Endocrinol Metab . 2010; 95( 2): 639– 650. Google Scholar CrossRef Search ADS PubMed  7. Fernández-Balsells MM, Murad MH, Lane M, Lampropulos JF, Albuquerque F, Mullan RJ, Agrwal N, Elamin MB, Gallegos-Orozco JF, Wang AT, Erwin PJ, Bhasin S, Montori VM. Clinical review 1: adverse effects of testosterone therapy in adult men: a systematic review and meta-analysis. J Clin Endocrinol Metab . 2010; 95( 6): 2560– 2575. Google Scholar CrossRef Search ADS PubMed  8. Haddad RM, Kennedy CC, Caples SM, Tracz MJ, Boloña ER, Sideras K, Uraga MV, Erwin PJ, Montori VM. Testosterone and cardiovascular risk in men: a systematic review and meta-analysis of randomized placebo-controlled trials. Mayo Clin Proc . 2007; 82( 1): 29– 39. Google Scholar CrossRef Search ADS PubMed  9. Snyder PJ, Ellenberg SS, Cunningham GR, Matsumoto AM, Bhasin S, Barrett-Connor E, Gill TM, Farrar JT, Cella D, Rosen RC, Resnick SM, Swerdloff RS, Cauley JA, Cifelli D, Fluharty L, Pahor M, Ensrud KE, Lewis CE, Molitch ME, Crandall JP, Wang C, Budoff MJ, Wenger NK, Mohler ER, Bild DE, Cook NL, Keaveny TM, Kopperdahl DL, Lee D, Schwartz AV, Storer TW, Ershler WB, Roy CN, Raffel LJ, Romashkan S, Hadley E. The Testosterone Trials: seven coordinated trials of testosterone treatment in elderly men. Clin Trials . 2014; 11( 3): 362– 375. Google Scholar CrossRef Search ADS PubMed  10. Snyder PJ, Bhasin S, Cunningham GR, Matsumoto AM, Stephens-Shields AJ, Cauley JA, Gill TM, Barrett-Connor E, Swerdloff RS, Wang C, Ensrud KE, Lewis CE, Farrar JT, Cella D, Rosen RC, Pahor M, Crandall JP, Molitch ME, Cifelli D, Dougar D, Fluharty L, Resnick SM, Storer TW, Anton S, Basaria S, Diem SJ, Hou X, Mohler ER III, Parsons JK, Wenger NK, Zeldow B, Landis JR, Ellenberg SS; Testosterone Trials Investigators. Effects of testosterone treatment in older men. N Engl J Med . 2016; 374( 7): 611– 624. Google Scholar CrossRef Search ADS PubMed  11. Budoff MJ, Ellenberg SS, Lewis CE, Mohler ER III, Wenger NK, Bhasin S, Barrett-Connor E, Swerdloff RS, Stephens-Shields A, Cauley JA, Crandall JP, Cunningham GR, Ensrud KE, Gill TM, Matsumoto AM, Molitch ME, Nakanishi R, Nezarat N, Matsumoto S, Hou X, Basaria S, Diem SJ, Wang C, Cifelli D, Snyder PJ. Testosterone treatment and coronary artery plaque volume in older men with low testosterone. JAMA . 2017; 317( 7): 708– 716. Google Scholar CrossRef Search ADS PubMed  12. Whitsel EA, Boyko EJ, Matsumoto AM, Anawalt BD, Siscovick DS. Intramuscular testosterone esters and plasma lipids in hypogonadal men: a meta-analysis. Am J Med . 2001; 111( 4): 261– 269. Google Scholar CrossRef Search ADS PubMed  13. Isidori AM, Giannetta E, Greco EA, Gianfrilli D, Bonifacio V, Isidori A, Lenzi A, Fabbri A. Effects of testosterone on body composition, bone metabolism and serum lipid profile in middle-aged men: a meta-analysis. Clin Endocrinol (Oxf) . 2005; 63( 3): 280– 293. Google Scholar CrossRef Search ADS PubMed  14. Kapoor D, Goodwin E, Channer KS, Jones TH. Testosterone replacement therapy improves insulin resistance, glycaemic control, visceral adiposity and hypercholesterolaemia in hypogonadal men with type 2 diabetes. Eur J Endocrinol . 2006; 154( 6): 899– 906. Google Scholar CrossRef Search ADS PubMed  15. Ng MK, Liu PY, Williams AJ, Nakhla S, Ly LP, Handelsman DJ, Celermajer DS. Prospective study of effect of androgens on serum inflammatory markers in men. Arterioscler Thromb Vasc Biol . 2002; 22( 7): 1136– 1141. Google Scholar CrossRef Search ADS PubMed  16. Malkin CJ, Pugh PJ, Jones RD, Kapoor D, Channer KS, Jones TH. The effect of testosterone replacement on endogenous inflammatory cytokines and lipid profiles in hypogonadal men. J Clin Endocrinol Metab . 2004; 89( 7): 3313– 3318. Google Scholar CrossRef Search ADS PubMed  17. Nakhai-Pour HR, Grobbee DE, Emmelot-Vonk MH, Bots ML, Verhaar HJ, van der Schouw YT. Oral testosterone supplementation and chronic low-grade inflammation in elderly men: a 26-week randomized, placebo-controlled trial. Am Heart J . 2007; 154( 6): 1228.e1– e7. Google Scholar CrossRef Search ADS   18. Jones PH, Davidson MH, Stein EA, Bays HE, McKenney JM, Miller E, Cain VA, Blasetto JW; STELLAR Study Group. Comparison of the efficacy and safety of rosuvastatin versus atorvastatin, simvastatin, and pravastatin across doses (STELLAR* Trial). Am J Cardiol . 2003; 92( 2): 152– 160. Google Scholar CrossRef Search ADS PubMed  19. Barter PJ, Brandrup-Wognsen G, Palmer MK, Nicholls SJ. Effect of statins on HDL-C: a complex process unrelated to changes in LDL-C: analysis of the VOYAGER Database. J Lipid Res . 2010; 51( 6): 1546– 1553. Google Scholar CrossRef Search ADS PubMed  20. Thompson PD, Cullinane EM, Sady SP, Chenevert C, Saritelli AL, Sady MA, Herbert PN. Contrasting effects of testosterone and stanozolol on serum lipoprotein levels. JAMA . 1989; 261( 8): 1165– 1168. Google Scholar CrossRef Search ADS PubMed  21. Rader DJ, Hovingh GK. HDL and cardiovascular disease. Lancet . 2014; 384( 9943): 618– 625. Google Scholar CrossRef Search ADS PubMed  Copyright © 2018 Endocrine Society

Journal

Journal of Clinical Endocrinology and MetabolismOxford University Press

Published: Feb 1, 2018

There are no references for this article.

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches

$49/month

Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.

$588

$360/year

billed annually
Start Free Trial

14-day Free Trial