Unravelling innervation of pancreatic isletsHampton, Rollie F.; Jimenez-Gonzalez, Maria; Stanley, Sarah A.
doi: 10.1007/s00125-022-05691-9pmid: 35348820
The central and peripheral nervous systems play critical roles in regulating pancreatic islet function and glucose metabolism. Over the last century, in vitro and in vivo studies along with examination of human pancreas samples have revealed the structure of islet innervation, investigated the contribution of sympathetic, parasympathetic and sensory neural pathways to glucose control, and begun to determine how the structure and function of pancreatic nerves are disrupted in metabolic disease. Now, state-of-the art techniques such as 3D imaging of pancreatic innervation and targeted in vivo neuromodulation provide further insights into the anatomy and physiological roles of islet innervation. Here, we provide a summary of the published work on the anatomy of pancreatic islet innervation, its roles, and evidence for disordered islet innervation in metabolic disease. Finally, we discuss the possibilities offered by new technologies to increase our knowledge of islet innervation and its contributions to metabolic regulation.Graphical abstract[graphic not available: see fulltext]
Elevated cerebrospinal fluid glucose levels and diabetes mellitus are associated with activation of the neurotoxic polyol pathwayTigchelaar, Celien; van Zuylen, Mark L.; Hulst, Abraham H.; Preckel, Benedikt; van Beek, André P.; Kema, Ido P.; Hermanides, Jeroen; Absalom, Anthony R.
doi: 10.1007/s00125-022-05693-7pmid: 35380232
Aims/hypothesisDuring hyperglycaemia, some glucose bypasses glycolysis and is metabolised via the potentially neurotoxic polyol pathway, in which glucose is metabolised to sorbitol and fructose. Increased polyol concentrations have been demonstrated in the cerebrospinal fluid (CSF) of neurological patients with and without diabetes mellitus. However, polyol levels in patients without evident neurological abnormalities have not been investigated so far. The aim of this study was to determine CSF polyol concentrations in patients without major neurological disease with normal or elevated CSF glucose concentrations.MethodsThis observational cohort study used CSF and plasma analyses, as well as clinical data, from 30 participants of the Anaesthetic Biobank of Cerebrospinal Fluid study. Biomaterial was collected from adult patients scheduled for elective surgery under spinal anaesthesia. CSF polyol concentrations were measured by GC/flame ionisation detector in ten patients with normal CSF glucose levels (group 1), ten patients with elevated CSF glucose levels (group 2) and ten patients with elevated CSF glucose levels and type 2 diabetes (group 3). We compared the concentrations of plasma glucose, CSF glucose, sorbitol and fructose, and CSF polyol/glucose ratios between the three groups, and determined the correlation between plasma glucose levels and CSF glucose, sorbitol and fructose levels.ResultsGroups 2 and 3 had significantly higher CSF fructose levels compared with group 1 (p=0.036 and p<0.001, respectively). Group 3 showed significant differences compared with groups 1 and 2 for CSF sorbitol (p<0.001 and 0.036, respectively). Moreover, patients with diabetes had a significantly higher CSF sorbitol/glucose ratio compared with patients without diabetes. There was a strong positive correlation between plasma glucose and CSF glucose, sorbitol and fructose. Finally, age, sex, CSF/plasma albumin ratio and preoperative cognitive function scores were significantly correlated with plasma glucose and CSF glucose, sorbitol and fructose levels.Conclusions/interpretationHyperglycaemia causes a proportional increase in polyol concentrations in CSF of patients without major neurological disease. Furthermore, this study provides the first indication of upregulation of the cerebral polyol pathway in patients with diabetes without evident neurological abnormalities.Graphical abstract[graphic not available: see fulltext]
Sleep deprivation prevents counterregulatory adaptation to recurrent hypoglycaemiaMeyhöfer, Svenja; Dembinski, Katharina; Schultes, Bernd; Born, Jan; Wilms, Britta; Lehnert, Hendrik; Hallschmid, Manfred; Meyhöfer, Sebastian M.
doi: 10.1007/s00125-022-05702-9pmid: 35445819
Aims/hypothesisAttenuated counterregulation after recurrent hypoglycaemia is a major complication of diabetes treatment. As there is previous evidence for the relevance of sleep in metabolic control, we assessed the acute contribution of sleep to the counterregulatory adaptation to recurrent hypoglycaemia.MethodsWithin a balanced crossover design, 15 healthy, normal-weight male participants aged 18–35 years underwent three hyperinsulinaemic–hypoglycaemic clamps with a glucose nadir of 2.5 mmol/l, under two experimental conditions, sleep and sleep deprivation. Participants were exposed to two hypoglycaemic episodes, followed by a third hypoglycaemic clamp after one night of regular 8 h sleep vs sleep deprivation. The counterregulatory response of relevant hormones (glucagon, growth hormone [GH], ACTH, cortisol, adrenaline [epinephrine] and noradrenaline [norepinephrine]) was measured, and autonomic and neuroglycopenic symptoms were assessed.ResultsSleep deprivation compared with sleep dampened the adaptation to recurrent hypoglycaemia for adrenaline (p=0.004), and this pattern also emerged in an overall analysis including adrenaline, GH and glucagon (p=0.064). After regular sleep, the counterregulatory responses of adrenaline (p=0.005), GH (p=0.029) and glucagon (p=0.009) were attenuated during the 3rd clamp compared with the 1st clamp, but were preserved after sleep deprivation (all p>0.225). Neuroglycopenic and autonomic symptoms during the 3rd clamp compared with the 1st clamp were likewise reduced after sleep (p=0.005 and p=0.019, respectively). In sleep deprivation, neuroglycopenic symptoms increased (p=0.014) and autonomic symptoms were unchanged (p=0.859).Conclusions/interpretationThe counterregulatory adaptation to recurrent hypoglycaemia is compromised by sleep deprivation between hypoglycaemic episodes, indicating that sleep is essential for the formation of a neurometabolic memory, and may be a potential target of interventions to treat hypoglycaemia unawareness syndrome.Graphical abstract[graphic not available: see fulltext]
Paternal eNOS deficiency in mice affects glucose homeostasis and liver glycogen in male offspring without inheritance of eNOS deficiency itselfHocher, Berthold; Lu, Yong-Ping; Reichetzeder, Christoph; Zhang, Xiaoli; Tsuprykov, Oleg; Rahnenführer, Jan; Xie, Li; Li, Jian; Hu, Liang; Krämer, Bernhard K.; Hasan, Ahmed A.
doi: 10.1007/s00125-022-05700-xpmid: 35488925
Aims/hypothesisIt was shown that maternal endothelial nitric oxide synthase (eNOS) deficiency causes fatty liver disease and numerically lower fasting glucose in female wild-type offspring, suggesting that parental genetic variants may influence the offspring’s phenotype via epigenetic modifications in the offspring despite the absence of a primary genetic defect. The aim of the current study was to analyse whether paternal eNOS deficiency may cause the same phenotype as seen with maternal eNOS deficiency.MethodsHeterozygous (+/−) male eNOS (Nos3) knockout mice or wild-type male mice were bred with female wild-type mice. The phenotype of wild-type offspring of heterozygous male eNOS knockout mice was compared with offspring from wild-type parents.ResultsGlobal sperm DNA methylation decreased and sperm microRNA pattern altered substantially. Fasting glucose and liver glycogen storage were increased when analysing wild-type male and female offspring of +/− eNOS fathers. Wild-type male but not female offspring of +/− eNOS fathers had increased fasting insulin and increased insulin after glucose load. Analysing candidate genes for liver fat and carbohydrate metabolism revealed that the expression of genes encoding glucocorticoid receptor (Gr; also known as Nr3c1) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Pgc1a; also known as Ppargc1a) was increased while DNA methylation of Gr exon 1A and Pgc1a promoter was decreased in the liver of male wild-type offspring of +/− eNOS fathers. The endocrine pancreas in wild-type offspring was not affected.Conclusions/interpretationOur study suggests that paternal genetic defects such as eNOS deficiency may alter the epigenome of the sperm without transmission of the paternal genetic defect itself. In later life wild-type male offspring of +/− eNOS fathers developed increased fasting insulin and increased insulin after glucose load. These effects are associated with increased Gr and Pgc1a gene expression due to altered methylation of these genes.Graphical abstract[graphic not available: see fulltext]
Early vs late histological confirmation of coeliac disease in children with new-onset type 1 diabetesKamrath, Clemens; Tittel, Sascha R.; Dunstheimer, Desiree; Fröhlich-Reiterer, Elke; Freff, Markus; Böttcher, Claudia; Scheffler, Nadine; Lenze, Stefanie; Gericke, Elke; Thiele, Susanne; Holl, Reinhard W.
doi: 10.1007/s00125-022-05701-wpmid: 35488926
AimScreening for coeliac disease in asymptomatic children with new-onset type 1 diabetes is controversial. The aim of this study was to analyse whether the confirmation of coeliac disease in children with new-onset type 1 diabetes and positive screening results can be postponed.MethodsThis was a multicentre population-based cohort study based on the German/Austrian/Swiss/Luxembourgian Prospective Diabetes Follow-up Registry (Diabetes Patienten Verlaufsdokumentation [DPV]). Participants aged ≤18 years diagnosed with type 1 diabetes between 1995 and June 2021 and with elevated IgA tissue transglutaminase antibodies (anti-tTGA) at diabetes onset on screening for coeliac disease were included. We compared outcomes of participants with a diabetes duration of more than 1 year between those in whom coeliac disease was confirmed histologically within the first 6 months and those in whom coeliac disease was confirmed between 6 and 36 months after diabetes diagnosis.ResultsOf 92,278 children and adolescents with a diagnosis of type 1 diabetes, 26,952 (29.2%) had documented anti-tTGA data at diabetes onset. Of these, 2340 (8.7%) had an elevated anti-tTGA level. Individuals who screened positive were younger (median age 9.0 vs 9.8 years, p<0.001) and more often female (53.1% vs 44.4%, p<0.001). A total of 533 participants (22.8% of those who screened positive) had a documented biopsy, of whom 444 had documented histological confirmation of coeliac disease. Of 411 participants with biopsy-proven coeliac disease within the first 36 months of diabetes and follow-up data, histological confirmation was performed in 264 (64.2%) within the first 6 months and in 147 (35.8%) between 6 and 36 months after diabetes onset. At follow-up (median diabetes duration 5.3 years and 5.1 years, respectively), estimated median HbA1c levels (62.8 mmol/mol vs 62.2 mmol/mol [7.9% vs 7.8%]), cardiovascular risk markers (lipids, rate of microalbuminuria, blood pressure), rates of acute diabetes complications (diabetic ketoacidosis, severe hypoglycaemia) and the proportions of participants reaching anti-tTGA levels within the normal range did not differ between groups. Participants with delayed histological confirmation of coeliac disease showed no negative effects on growth or weight gain during the observation period.ConclusionsOur study suggests that the histological confirmation of coeliac disease in asymptomatic individuals with new-onset type 1 diabetes could be postponed.Graphical abstract[graphic not available: see fulltext]
Incident cardiovascular disease by clustering of favourable risk factors in type 1 diabetes: the EURODIAB Prospective Complications StudySoulimane, Soraya; Balkau, Beverley; Vogtschmidt, Yakima D.; Toeller, Monika; Fuller, John H.; Soedamah-Muthu, Sabita S.
doi: 10.1007/s00125-022-05698-2pmid: 35411407
AimsThe aim of this prospective study was to examine CVD risk reduction in type 1 diabetes (1) for people with favourable cardiovascular health metrics and (2) by clustering of these metrics.MethodsData from 2313 participants from the EURODIAB Prospective Complications Study were analysed. All had type 1 diabetes (51% men, mean ± SD age 32 ± 9 years). Seven cardiovascular health metrics were studied—smoking, BMI, physical activity, a diet score, total cholesterol/HDL-cholesterol ratio, combined systolic and diastolic BP and HbA1c—divided into favourable/less favourable categories. Cox proportional hazards models were used to calculate HRs (95% CIs) of incident CVD for each metric. Clusters were made by scoring each individual by the number of favourable metrics.ResultsA total of 163 people developed incident CVD during a mean ± SD follow-up of 7.2 ± 1.3 years. Participants with more favourable HbA1c levels of <57 mmol/mol (<7.4%) had a 37% significantly lower CVD risk than those with a less favourable HbA1c (HR [95% CI] 0.63 [0.44, 0.91]), and participants with a more favourable BP (systolic BP <112 mmHg and diastolic BP <70 mmHg) had a 44% significantly lower CVD risk than participants in the less favourable BP group (HR [95% CI] 0.56 [0.34, 0.92]). There was a dose–response relation with a lower HR observed with greater clustering of more favourable metrics: people with four or more favourable metrics had an HR of 0.37 (95% CI 0.18, 0.76), adjusted for sex and age at diabetes diagnosis, compared with those with no favourable metrics.Conclusions/interpretationLow HbA1c and low BP were protective cardiovascular health metrics in our study of people with type 1 diabetes. Targeting all cardiovascular health metrics could be more effective in preventing CVD than targeting single metrics.Graphical abstract[graphic not available: see fulltext]