American Journal of Epidemiology

BLOEM, MARTIN W.; WEDEL, MICHEL; EGGER, ROBBERT J.; SPEEK, ANDRIES J.; CHUSILP, KUSUMA; SAOWAKONTHA, SASTRI; SCHREURS, W. H. P.

doi: 10.1093/oxfordjournals.aje.a115231pmid: 2786327

An epidemiologic survey of the prevalence of xerophthalmia and vitamin A deficiency was conducted in May and June 1985 in a multistage random sample of 1,772 children 1–8 years of age from 16 rural villages and the capital city of the Sakon Nakhon province in northeastern Thailand. Data of clinical eye examinations were available for 92% (n = 903) of the eligible children aged 1–5 years (n = 982); history of night blindness was obtained from a reliable source from 93% (n = 1,644) of the whole sample; and biochemical data were available for 60% (1,060) of the children examined. The distribution of clinical signs of xerophthalmia and serum retinol levels differed between the rural and urban areas. In the urban area, no signs of xerophthalmia or deficient serum retinol levels were found in the preschool children examined. The prevalence of night blindness in the rural area was 1.3% in children aged 1–5 years (95% confidence interval (Cl) 0.7–1.9); Bltot's spots were seen in 0.4% (95% Cl 0.1–1.0); 12.7% (95% Cl 9.9–15.5) showed deficient serum retinol levels (<0.35μmol/liter). Of the children aged 1–8 years, 9.6% (95% Cl 7.8–11.4) showed deficient serum retinol levels. In the rural area, the prevalence of night blindness, Bitot's spots, and deficient serum retinol levels indicates a problem of public health importance according to World Health Organization criteria.

KARAGAS, MARGARET R.; WEISS, NOEL S.; STRADER, CLIFTON H.; DALING, JANET R.

doi: 10.1093/oxfordjournals.aje.a115232pmid: 2543215

The possibility that intrascrotal temperature is involved in the etiology of testicular cancer was investigated through a population-based case-control study conducted in western Washington State. A total of 323 men with germ cell tumors of the testis diagnosed between 1977 and 1984 and 658 randomly selected controls were interviewed with regard to type of shorts worn, use of long underwear, heat-resistant clothing, and hot tubs or saunas, and a history of vancocele. No association was found between testicular cancer and having worn tight-fitting underwear (jockey shorts) or having worn heat-resistant clothing on the job. A 50% increase in risk was observed for men who typically wore long underwear for more than three months out of the year, but this association was within the limits of chance given no true association. A smaller fraction of the men with cancer than controls had used a hot tub or sauna in the preceding five years, but the size of the case-control difference was not related to the frequency of use. The relative risk associated with a history of physician-diagnosed varicocele was 1.8 (95% confidence interval 0.9–3.4). There was little difference between men with seminomas and those with other germ cell tumors regarding any of the above exposures. Taken in aggregate, these results provide little or no support for the hypothesis that intermittent intrascrotal temperature elevation, to the degree encountered by US men today, plays a role in the etiology of germ cell testicular cancer. The possibility that risk increases after a continuous temperature increase, such as might result from a vancocele, needs to be evaluated further.

CRIQUI, MICHAEL H.; BROWNER, DEIRDRE; FRONEK, ARNOST; KLAUBER, MELVILLE R.; COUGHLIN, STEVEN S.; BARRETT-CONNOR, ELIZABETH; GABRIEL, SAM

doi: 10.1093/oxfordjournals.aje.a115233pmid: 2786328

The authors used noninvasive techniques, including flow velocity by Doppler ultrasound, to accurately assess and distinguish between large and small vessel peripheral arterial disease in a population study in southern California, 1978–1981. In 565 men and women aged 38–82 years, there were 69 cases of large vessel peripheral arterial disease, 19 of which were severe, and 90 cases of isolated small vessel peripheral arterial disease. In cross-sectional multivariate analysis in men, large vessel peripheral arterial disease was significantly associated with age, pack-years of cigarettes smoked, systolic blood pressure, fasting plasma glucose, and marginally with obesity. Similar analysis in women revealed significant associations only for age and systolic blood pressure, although the associations for pack-years of cigarettes, obesity, and low density lipoprotein cholesterol were suggestive. By contrast, isolated small vessel peripheral arterial disease was not significantly associated with any of the major cardiovascular disease risk factors, including two measures of carbohydrate metabolism, fasting plasma glucose and glycosylated hemoglobin. These findings, coupled with our earlier report that large vessel peripheral arterial disease but not isolated small vessel peripheral arterial disease was independently predictive of subsequent mortality, suggest that large vessel peripheral arterial disease and isolated small vessel peripheral arterial disease are epidemiologically, as well as pathophysiologically, distinct entities.

CAULEY, JANE A.; GUTAI, JAMES P.; KULLER, LEWIS H.; LEDONNE, DOROTHEA; POWELL, JOHN G.

doi: 10.1093/oxfordjournals.aje.a115234pmid: 2729251

Serum sex hormones may be related to the risk of several diseases in postmenopausal women. In the current report, the authors examined the epidemiology of serum sex hormones in 176 healthy, white postmenopausal women (mean age 58 years) recruited from the metropolitan Pittsburgh, Pennsylvania, area. The data were collected during 1982–1983; none of the women were on estrogen replacement therapy. Serum concentrations of estrone, estradiol, testosterone, and androstenedione were measured by a combination of extraction, column chromatography, and radiolmmunoassay. Neither age nor time since menopause was a significant predictor of sex hormones. The degree of obesity was a major determinant of estrone and estradiol. The estrone levels of obese women were about 40% higher than the levels of nonobese women. There was a weak relation between obesity and the androgens. Cigarette smokers had significantly higher levels of androstenedione than nonsmokers, with little difference in serum estrogens between smokers and nonsmokers. Both estrone and estradiol levels tended to decline with increasing alcohol consumption. Physical activity was an independent predictor of serum estrone. More active women had lower levels of estrone. There was a positive relation of muscle strength with estrogen levels. The data suggest interesting relations between environmental and lifestyle factors and serum sex hormones. These environmental and lifestyle factors are potentially modifiable and, hence, if associations between sex hor mones and disease exist, modification of these factors could affect disease risks.

MATTHEWS, KAREN A.; KELSEY, SHERYL F.; MEILAHN, ELAINE N.; MULLER, LEWIS H.; WING, RENA R.

doi: 10.1093/oxfordjournals.aje.a115235pmid: 2729252

Epidemiologic investigations have shown that low socioeconomic status is related to ischemic coronary heart disease mortality in men and women as well as to major risk factors for coronary heart disease, predominantly in men. The present study investigated the associations between educational attainment and biologic and behavioral risk factors for coronary heart disease in a community sample of 2,138 middle-aged women residing in Allegheny County, Pennsylvania. The women were contacted between 1983 and 1985 to determine eligibility for a study of risk factor changes during the penmenopausal period. Eligibility criteria included age 42 to 50 years, premenopausal status, diastolic blood pressure <100 mmHg, and nonuse of medications known to influence risk factors. Among the 541 eligible participants, the less education the women reported, the more atherogenic was their risk factor profile, including higher systolic blood pressure, low density lipoprotein (LDL) cholesterol, apolipoprotein B, triglycerides, fasting and two-hour glucose values, two-hour insulin values, body mass indices, and lower high density lipoprotein (HDL) cholesterol and HDL/LDL ratio; the more often they reported being cigarette smokers, taking little physical exercise, and consuming alcohol less than one day a week; the more often they reported on standardized psychologic tests being Type B, angry, pessimistic, depressed, and dissatisfied with paid work, and having little social support and self-esteem (all p values <0.01). Similar associations were obtained between educational attainment and risk factors reported by the 1,588 nonparticipants during the telephone screening interview. These results suggest many biologic and behavioral factors by which women with little education are at elevated risk for coronary heart disease. To the extent that advanced education protects women against coronary heart disease, a potentially important public health intervention for women is education.

BLAIR, STEVEN N.; KANNEL, WILLIAM B.; KOHL, HAROLD W.; GOODYEAR, NANCY; WILSON, PETER W. F.

doi: 10.1093/oxfordjournals.aje.a115236pmid: 2729253

Studies on physical activity, physical fitness, and health have been hampered because of invalid, unreliable, or impractical measures of physical activity. This report examines the validity of sedentary traits (resting tachycardia, obesity, and low vital capacity) as predictors of physical fitness as assessed by a maximal treadmill exercise test. Study participants were women (n = 3,94.3) and men (n = 15,627) with at least one visit to the Cooper Clinic in Dallas, Texas. Association of the sedentary traits with physical fitness was examined by multiple regression analyses. Sedentary traits were associated with physical fitness in all age and sex groups, accounting for 12–40% of the variance in treadmill time. When smoking, a simple physical activity index, and sedentary traits were included in a model to predict physical fitness, R2 values ranged from 0.20 to 0.53 in women and 0.45 to 0.61 in men and were significant at p < 0.0001. These models account for approximately twice as much variance in physical fitness as has been reported previously. The addition of sedentary traits measurements to a simple physical activity index provides a valid estimate of physical fitness in epidemiologic studies.

VOLLMER, WILLIAM M.; MCCAMANT, LYNN E.; JOHNSON, LARRY R.; BUIST, A. SONIA

doi: 10.1093/oxfordjournals.aje.a115237pmid: 2729254

Numerous studies have documented the effects of smoking and reduced pulmonary function on all-cause mortality. The effects of respiratory symptoms are less well studied. This paper examines the joint effects of respiratory symptoms, lung function, and smoking using 11-year mortality data on 698 subjects aged 25 years and older. Copies of death certificates were obtained for all 120 confirmed deaths, and cause of death was coded by a nosologist using the rules of the international Classification of Diseases, Ninth Revision. Symptoms of cough/phlegm, wheeze, and dyspnea were significantly associated with all-cause mortality in separate univanate analyses. On a cause-specific basis, these associations appeared to hold for chronic obstructive pulmonary disease, lung cancer, and vascular disease. Further analysis indicated that, for both smokers and nonsmokers, the presence of chronic cough and/or sputum production was related to mortality only in the presence of wheezing. In addition, among smokers, the presence of both cough/phlegm and wheeze was significantly associated with mortality only among subjects with low initial lung function. Although the limited number of deaths and the nonrandom nature of the cohort limit the generalizability of our findings, it seems clear, based on these results and other published studies, that symptoms of cough, phlegm, and/or wheeze have important adverse health implications even in the absence of smoking and reduced lung function. More studies using common methodological approaches are needed.

PUENTE, ANTONIO DEL; KNOWLER, WILLIAM C.; PETTITT, DAVID J.; BENNETT, PETER H.

doi: 10.1093/oxfordjournals.aje.a115238pmid: 2786329

A longitudinal epidemiologic study has been conducted to estimate the incidence and prevalence of rheumatoid arthritis in an American Indian population, the Pima and Papago Indians of Arizona. Clinical, serologic, and radiologic data were collected during biennial examinations of subjects aged 20 years or more during the period 1967–1986. Rheumatoid arthritis was diagnosed by criteria for the active and the inactive disease. Age-adjusted to the 1980 US population at least 20 years of age, the prevalence of classical and definite rheumatoid arthritis in 1984 was 5.3% (3.23% in males and 6.95% in females), a rate appreciably higher than that reported in studies in Rochester, Minnesota, and in Hiroshima and Nagasaki, Japan. Among Pimas, during the study period, 70 incident cases of rheumatoid arthritis occurred. The age-adjusted incidence rate was 42.2 cases per 10,000 person-years (29.7 in males and 51.8 in females), 10.3 times as high as the age-adjusted rate in Rochester (4.1/10,000 person-years), and 5.7 times as high as in Japan (7.4/10,000 person-years). Rates generally increased with age. No secular trend was found. On the basis of both prevalence and incidence data, this study confirms that rheumatoid arthritis does not have uniform occurrence in different populations. This has to be taken into account in the search for the factors related to the differences in risk of disease.

KLOTZ, JUDITH B.; PETIX, JULIE R.; ZAGRANISKI, REBECCA T.

doi: 10.1093/oxfordjournals.aje.a115239pmid: 2729255

A historical cohort mortality study was conducted in three neighborhoods of Essex County, New Jersey, to investigate the mortality patterns of persons who had inhabited 45 homes documented to be contaminated by radon gas emanating from radium processing waste. Residency history and vital status were collected for 752 persons, comprising 91% of the subjects enumerated who had resided in the index homes for at least one year during the years 1923–1983. Standardized mortality ratios (SMR) were used to compare the death rates of the study group with the death rates of the United States and New Jersey. While there were no statistically significant excesses of lung cancer for the cohort or its subgroups, an elevated mortality rate for lung cancer was found for white males in the comparison of lung cancer mortality rates in the United States (SMR = 1.5, 95% confidence interval (Cl) 0.7–2.7) and New Jersey (SMR = 1.7, 95% Cl 0.8–3.2). No excess of lung cancer was observed in females or nonwhites. The small size of the cohort and the inability to collect smoking histories or complete occupational data limited the study. Nevertheless, the degree of excess lung cancer among white males was in agreement with both the attributable and relative risk estimates per unit of exposure derived for radon from mining studies.

BERTAZZI, PIER ALBERTO; ZOCCHETTI, CARLO; PESATORI, ANGELA C.; GUERCILENA, STEFANO; SANARICO, MAURIZIO; RADICE, LAURA

doi: 10.1093/oxfordjournals.aje.a115240pmid: 2729256

In 1976, an accidental explosion in a plant near Seveso, Italy, caused the contamination of a populated area by 2,3,7,8-tetrachlorodibenzo-p-dloxin (TCDD). The area was subdivided into three zones (A, B, and R) having decreasing mean levels of TCDD soil contamination. This study examines the mortality between 1976 and 1986 among the subjects, aged 20–74 years, who were resident In the area since the accident (n = 556 in zone A, n = 3,920 in zone B, n = 26,227 in zone R). Subjects' exposure was classified by residence. A referent cohort of 167,391 subjects who lived in the immediate surroundings was concurrently examined. Vital status ascertainment was successful for over 99% of the subjects. Increased mortality from cardiovascular causes was found; incident-related stressors were considered more relevant to increased mortality than was TCDD exposure. Mortality from several cancers was elevated. The increases in billary cancer (females), brain cancer, and lymphatic and hemopoietlc neoplasms (particularly leukemia in males) did not appear to result from chance, confounding, or information/comparison bias. However, no definite patterns related to exposure classification were apparent. Merely suggestive increases in soft tissue tumors and melanoma were also noted. Liver and breast cancer mortality tended to be below expectations. Interpretation is hampered by the short observation period, small number of deaths from certain causes, and poor exposure definition. Further research is in progress.