Phenotypic and genotypic differences between Indian and Scandinavian women with gestational diabetes mellitus.

OBJECTIVE: Gestational diabetes mellitus (GDM) is a transient form of diabetes characterized by impaired insulin secretion and action during pregnancy. Population-based differences in prevalence exist which could be explained by phenotypic and genetic differences. The aim of this study was to examine these differences in pregnant women from Punjab, India and Scandinavia. METHODS: Eighty-five GDM/T2D loci in European and/or Indian populations from previous studies were assessed for association with GDM based on Swedish GDM criteria in 4018 Punjabi Indian and 507 Swedish pregnant women. Selected loci were replicated in Scandinavian cohorts, Radiel (N = 398, Finnish) and STORK/STORK-G (N = 780, Norwegian). RESULTS: Punjabi Indian women had higher GDM prevalence, lower insulin secretion and better insulin sensitivity than Swedish women. There were significant frequency differences of GDM/T2D risk alleles between both populations. rs7178572 at HMG20A, previously associated with GDM in South Indian and European women, was replicated in North Indian women. The T2D risk SNP rs11605924 in the CRY2 gene was associated with increased GDM risk in Scandinavian but decreased GDM risk in Punjabi Indian women. No other overlap was seen between GDM loci in both populations. CONCLUSIONS: Gestational diabetes mellitus is more common in Indian than Swedish women, which partially can be attributed to differences in insulin secretion and action. There was marked heterogeneity in the GDM phenotypes between the populations which could only partially be explained by genetic differences.

Insulin secretion and action in North Indian women during pregnancy.

AIM: The relative roles(s) of impaired insulin secretion vs. insulin resistance in the development of gestational diabetes mellitus depend upon multiple risk factors and diagnostic criteria. Here, we explored their relative contribution to gestational diabetes as defined by the WHO 1999 (GDM1999) and adapted WHO 2013 (GDM2013) criteria, excluding the 1-h glucose value, in a high-risk Indian population from Punjab. METHODS: Insulin secretion (HOMA2-B) and insulin action (HOMA2-IR) were assessed in 4665 Indian women with or without gestational diabetes defined by the GDM1999 or adapted GDM2013 criteria. RESULTS: Gestational diabetes defined using both criteria was associated with decreased insulin secretion compared with pregnant women with normal glucose tolerance. Women with gestational diabetes defined by the adapted GDM2013, but not GDM1999 criteria, were more insulin resistant than pregnant women with normal glucose tolerance, and furthermore displayed lower insulin secretion than GDM1999 women. Urban habitat, illiteracy, high age and low BMI were independently associated with reduced insulin secretion, whereas Sikh religion, increasing age and BMI, as well as a family history of diabetes were independently associated with increased insulin resistance. CONCLUSIONS: Gestational diabetes risk factors influence insulin secretion and action in North Indian women in a differential manner. Gestational diabetes classified using the adapted GDM2013 compared with GDM1999 criteria is associated with more severe impairments of insulin secretion and action.

Effects of 12 weeks' treatment with a proton pump inhibitor on insulin secretion, glucose metabolism and markers of cardiovascular risk in patients with type 2 diabetes: a randomised double-blind prospective placebo-controlled study.

AIMS/HYPOTHESIS: Recent studies suggest that proton pump inhibitor treatment may increase insulin secretion and improve glucose metabolism in type 2 diabetes. In a randomised double-blind prospective placebo-controlled 2 × 2 factorial study, we examined the effect of esomeprazole on insulin secretion, HbA(1c) and cardiovascular risk factors in type 2 diabetes. METHODS: Forty-one patients with type 2 diabetes using dietary control or oral glucose-lowering treatment were randomised to receive add-on esomeprazole 40 mg (n = 20) or placebo (n = 21) for 12 weeks. Randomisation was carried out prior to inclusion on the basis of a computer-generated random-number list. The allocation sequence was concealed in sealed envelopes from the researcher enrolling and assessing participants. The study was undertaken at Steno Diabetes Center, Gentofte, Denmark. The primary outcome was change in AUC for insulin levels during a meal test. Secondary outcomes were the levels of HbA(1c) and biochemical markers of cardiovascular risk, including lipids, coagulation factors, inflammation markers, markers of endothelial function and 24 h ambulatory BP measurements. RESULTS: Forty-one participants were analysed. In the esomeprazole-treated group the AUC for insulin did not change (before vs after treatment: 28,049 ± 17,659 vs 27,270 ± 32,004 pmol/l × min (p = 0.838). In the placebo group AUC for insulin decreased from 27,392 ± 14,348 pmol/l × min to 22,938 ± 11,936 pmol/l × min (p = 0.002). Esomeprazole treatment (n = 20) caused a ninefold increase in the AUC for gastrin. HbA(1c) increased from 7.0 ± 0.6% (53 ± 5 mmol/mol) to 7.3 ± 0.8% (56 ± 6 mmol/mol) in the esomeprazole-treated group and from 7.0 ± 0.6% (53 ± 5 mmol/mol) to 7.4 ± 0.8% (57 ± 6 mmol/mol) in the placebo group (n = 21) (p for difference in change >0.05). Except for BP, there were no differences between the groups in the markers of cardiovascular risk (p > 0.05). Monitoring of 24 h ambulatory BP showed a significant decrease in daytime systolic BP, daytime diastolic BP and 24 h diastolic BP in the placebo group (p < 0.05). No change in BP was seen in the patients treated with esomeprazole. CONCLUSIONS/INTERPRETATION: Treatment with esomeprazole over 12 weeks did not improve insulin secretion, glycaemic control or cardiovascular disease biomarkers in patients with type 2 diabetes.

The thrifty phenotype hypothesis revisited.

Twenty years ago, Hales and Barker along with their co-workers published some of their pioneering papers proposing the 'thrifty phenotype hypothesis' in Diabetologia (4;35:595-601 and 3;36:62-67). Their postulate that fetal programming could represent an important player in the origin of type 2 diabetes, the metabolic syndrome and cardiovascular disease (CVD) was met with great scepticism.More recently, their observations have been confirmed and expanded in many epidemiological and animal experimental studies, and human integrative physiological studies have provided insights into some of the underlying molecular mechanisms. Type 2 diabetes is a multiple-organ disease, and developmental programming, with its idea of organ plasticity, is a plausible hypothesis for a common basis for the widespread organ dysfunctions in type 2 diabetes and the metabolic syndrome. Only two among the 45 known type 2 diabetes susceptibility genes are associated with low birthweight, indicating that the association between low birthweight and type 2 diabetes is mainly non-genetic. Prevention programmes targeting adult lifestyle factors seems unable to stop the global propagation of type 2 diabetes, and intensive glucose control is inadequate to reduce the excess CVD mortality in type 2 diabetic patients. Today, the thrifty phenotype hypothesis has been established as a promising conceptual framework for a more sustainable intergenerational prevention of type 2 diabetes.

Effects of short-term high-fat overfeeding on genome-wide DNA methylation in the skeletal muscle of healthy young men.

AIMS/HYPOTHESIS: Energy-dense diets that are high in fat are associated with a risk of metabolic diseases. The underlying molecular mechanisms could involve epigenetics, as recent data show altered DNA methylation of putative type 2 diabetes candidate genes in response to high-fat diets. We examined the effect of a short-term high-fat overfeeding (HFO) diet on genome-wide DNA methylation patterns in human skeletal muscle. METHODS: Skeletal muscle biopsies were obtained from 21 healthy young men after ingestion of a short-term HFO diet and a control diet, in a randomised crossover setting. DNA methylation was measured in 27,578 CpG sites/14,475 genes using Illumina's Infinium Bead Array. Candidate gene expression was determined by quantitative real-time PCR. RESULTS: HFO introduced widespread DNA methylation changes affecting 6,508 genes (45%), with a maximum methylation change of 13.0 percentage points. The HFO-induced methylation changes were only partly and non-significantly reversed after 6-8 weeks. Alterations in DNA methylation levels primarily affected genes involved in inflammation, the reproductive system and cancer. Few gene expression changes were observed and these had poor correlation to DNA methylation. CONCLUSIONS/INTERPRETATION: The genome-wide DNA methylation changes induced by the short-term HFO diet could have implications for our understanding of transient epigenetic regulation in humans and its contribution to the development of metabolic diseases. The slow reversibility suggests a methylation build-up with HFO, which over time may influence gene expression levels.

The disposition index: adjustment for peripheral vs. hepatic insulin sensitivity?

The assessment of pancreatic beta cell function in humans is challenging because of a complex interplay between insulin secretion, insulin sensitivity and hepatic insulin extraction. Simplified, the relationship between insulin secretion and insulin sensitivity can be described by an approximate hyperbola with the product of the two variables being constant for individuals with the same degree of glucose tolerance (the disposition index). Strengths and limitations of the disposition index have been widely debated in the literature. In this review we will focus on another and until recently unrecognized dimension of the disposition index, namely the issue of adjusting insulin secretion for hepatic versus peripheral insulin sensitivity. An underlying assumption of this issue is that the liver as compared to muscle plays a different role in the regulation of in vivo insulin secretion.

The T allele of rs7903146 TCF7L2 is associated with impaired insulinotropic action of incretin hormones, reduced 24 h profiles of plasma insulin and glucagon, and increased hepatic glucose production in young healthy men.

AIMS/HYPOTHESIS: We studied the physiological, metabolic and hormonal mechanisms underlying the elevated risk of type 2 diabetes in carriers of TCF7L2 gene. METHODS: We undertook genotyping of 81 healthy young Danish men for rs7903146 of TCF7L2 and carried out various beta cell tests including: 24 h glucose, insulin and glucagon profiles; OGTT; mixed meal test; IVGTT; hyperglycaemic clamp with co-infusion of glucagon-like peptide (GLP)-1 or glucose-dependent insulinotropic polypeptide (GIP); and a euglycaemic-hyperinsulinaemic clamp combined with glucose tracer infusion to study hepatic and peripheral insulin action. RESULTS: Carriers of the T allele were characterised by reduced 24 h insulin concentrations (p < 0.05) and reduced insulin secretion relative to glucose during a mixed meal test (beta index: p < 0.003), but not during an IVGTT. This was further supported by reduced late-phase insulinotropic action of GLP-1 (p = 0.03) and GIP (p = 0.07) during a 7 mmol/l hyperglycaemic clamp. Secretion of GLP-1 and GIP during the mixed meal test was normal. Despite elevated hepatic glucose production, carriers of the T allele had significantly reduced 24 h glucagon concentrations (p < 0.02) suggesting altered alpha cell function. CONCLUSIONS/INTERPRETATION: Elevated hepatic glucose production and reduced insulinotropic effect of incretin hormones contribute to an increased risk of type 2 diabetes in carriers of the rs7903146 risk T allele of TCF7L2.

Leukocyte telomere length is associated with elevated plasma glucose and HbA1c in young healthy men independent of birth weight.

Telomeres are protein-bound regions of repetitive nucleotide sequences (TTAGGG) at the end of human chromosomes, and their length is a marker of cellular aging. Intrauterine growth restriction is associated with shorter blood cell telomeres at birth and individuals with type 2 diabetes have shorter telomeres. Individuals with a low birth weight (LBW) have an increased risk of metabolic disease and type 2 diabetes. Therefore, we aimed to investigate the relationship between birth weight and telomere length and the association between birth weight, telomere length and cardiometabolic phenotype in adulthood. Young, healthy men with LBW (n = 55) and normal birth weight (NBW) (n = 65) were examined including blood pressure, blood samples and body composition. Leukocyte telomere length was determined using a high-throughput qPCR method. The LBW men were more insulin resistant as determined by the HOMA-IR index. There was no difference in telomere length between LBW and NBW subjects. When adjusting for birth weight and cohort effect, significant negative associations between telomere length and fasting glucose (P = 0.003) and HbA1c (P = 0.0008) were found. In conclusion, no significant difference in telomere length was found between LBW and NBW men. The telomere length was negatively associated with glucose concentrations and HbA1c levels within the normal non-diabetic range independent of birth weight.

Effects of 12 weeks of treatment with fermented milk on blood pressure, glucose metabolism and markers of cardiovascular risk in patients with type 2 diabetes: a randomised double-blind placebo-controlled study.

OBJECTIVE: Studies have indicated a blood pressure (BP)-lowering effect of milk-derived peptides in non-diabetic individuals, but the cardiometabolic effects of such peptides in patients with type 2 diabetes (T2D) are not known. We investigated the effect of milk fermented with Lactobacillus helveticus on BP, glycaemic control and cardiovascular risk factors in T2D. DESIGN: A randomised, double-blinded, prospective, placebo-controlled study. METHODS: In one arm of a factorial study design, 41 patients with T2D were randomised to receive 300 ml milk fermented with L. helveticus (Cardi04 yogurt) (n=23) or 300 ml artificially acidified milk (placebo yogurt) (n=18) for 12 weeks. BPs were measured over 24-h, and blood samples were collected in the fasting state and during a meal test before and after the intervention. RESULTS: Cardi04 yogurt did not reduce 24-h, daytime or nighttime systolic or diastolic BPs compared with placebo (P>0.05). Daytime and 24-h heart rate (HR) were significantly reduced in the group treated by Cardi04 yogurt compared with the placebo group (P<0.05 for both). There were no differences in HbA1c, plasma lipids, C-reactive protein, plasminogen activator inhibitor-1, tumour necrosis factor alpha, tissue-type plasminogen activator: Ag, and von Willebrand factor: Ag between the groups. The change in fasting blood glucose concentration differed significantly between the two groups with a larger increase in the placebo group (P<0.05). CONCLUSIONS: Ingestion of milk fermented with L. helveticus compared with placebo for 12 weeks did not significantly reduce BP in patients with T2D. Our finding of lower HRs and fasting plasma glucose levels in T2D patients during ingestion of fermented milk needs further validation.

Effect of taurine treatment on insulin secretion and action, and on serum lipid levels in overweight men with a genetic predisposition for type II diabetes mellitus.

BACKGROUND: The prevalence of type 2 diabetes mellitus (T2DM) is increasing with an epidemic growth rate. Animal studies with taurine supplementation have shown increased insulin secretion and action, suggesting that taurine supplementation may have a potential to prevent T2DM. OBJECTIVE: To assess the effect of taurine treatment on insulin secretion and action, and on plasma lipid levels in overweight men with a positive history of T2DM. DESIGN: 20 nondiabetic subjects were included in a double-blinded, randomized, crossover study, receiving a daily supplementation of 1.5 g taurine or placebo for two periods of 8 weeks. The subjects were overweight first-degree relatives of T2DM patients. An intravenous glucose tolerance test (IVGTT) was used to measure first-phase insulin secretory response, and a euglycemic hyperinsulinemic clamp was used to determine peripheral insulin action. RESULTS: Mean plasma taurine concentration was 39 +/- 7 (s.d.) micromol/l after placebo and 131 +/- 62 micromol/l after taurine intervention (P < 0.0001). There was no significant difference after taurine intervention compared to placebo in incremental insulin response (Insincr.) neither during the IVGTT, nor in insulin-stimulated glucose disposal during the clamp. Insulin secretion, adjusted for insulin sensitivity, was also unchanged. There was no significant effect of taurine supplementation on blood lipid levels as well. CONCLUSION: Daily supplementation with 1.5 g taurine for 8 weeks had no effect on insulin secretion or sensitivity, or on blood lipid levels. These findings in persons with an increased risk of T2DM are in contrast to those from animal studies, and do not support the assumption that dietary supplementation with taurine can be used to prevent the development of T2DM.

[Cognitive functions and school achievement of children who were treated for acute lymphatic leukemia at a young age]. / Cognitieve functies en schoolprestaties van kinderen, die op jonge leeftijd werden behandeld voor acute lymfatische leukemie.

Neuropsychologic tests were performed in 40 children with acute lymphoblastic leukemia. They all had been treated at a young age with systemic chemotherapy, cranial irradiation and intrathecal methotrexate. The test results showed a high risk for learning disabilities. Visual motor integration problems were present early after cessation of treatment, but most cognitive defects became apparent about 2 years after stopping therapy. At that time 23% (9/40) of the children required special school types and 30% (12/40) needed additional help within their residential school. Problems with arithmetic were most prominent. Future study of patients who did not receive prophylactic irradiation of the brain will help to clarify the potential causative role of cranial irradiation in these cognitive defects.

Increased nocturnal fat oxidation in young healthy men with low birth weight: results from 24-h whole-body respiratory chamber measurements.

OBJECTIVE: Low birth weight (LBW), a marker of disturbed fetal growth, is associated with adiposity and increased risk of type 2 diabetes (T2D). The aim of the study was to investigate whether LBW is associated with changes in 24-h energy expenditure (EE) and/or substrate utilization rates, potentially contributing to the development of adiposity and/or T2D compared to matched control subjects. MATERIALS/METHODS: Forty-six young, healthy men were included in the study; 20 with LBW (≤ 10th percentile) and 26 control subjects with normal birth weight (NBW) (50th-90th percentile). The subjects were fed a weight maintenance diet and 24-h energy expenditure (EE), respiratory quotient (RQ), and substrate oxidation were assessed in a respiratory chamber. RESULTS: No differences in 24-h EE, RQ or substrate oxidation were observed between LBW and controls. Interestingly, the LBW group exhibited lower nocturnal RQ compared to controls (0.81 ± 0.01 vs. 0.85 ± 0.01 (mean ± SE), P = 0.01), and hence higher nocturnal fat oxidation (2.55 ± 0.13 vs. 2.09 ± 0.12 kJ/min (mean ± SE), P = 0.02). CONCLUSIONS: Young LBW men do not exhibit reductions in 24-h EE. However, LBW subjects display increased nocturnal fat oxidation at the expense of reduced glucose oxidation. We speculate that this may be associated with insufficient capability to retain fat in subcutaneous adipose tissue after meals during day time, with an increased rate of nocturnal and morning lipolysis, and potentially with subtle elevations of gluconeogenesis and of fasting glucose levels in the LBW subjects.

Programming of adipose tissue miR-483-3p and GDF-3 expression by maternal diet in type 2 diabetes.

Nutrition during early mammalian development permanently influences health of the adult, including increasing the risk of type 2 diabetes and coronary heart disease. However, the molecular mechanisms underlying such programming are poorly defined. Here we demonstrate that programmed changes in miRNA expression link early-life nutrition to long-term health. Specifically, we show that miR-483-3p is upregulated in adipose tissue from low-birth-weight adult humans and prediabetic adult rats exposed to suboptimal nutrition in early life. We demonstrate that manipulation of miR-483-3p levels in vitro substantially modulates the capacity of adipocytes to differentiate and store lipids. We show that some of these effects are mediated by translational repression of growth/differentiation factor-3, a target of miR-483-3p. We propose that increased miR-483-3p expression in vivo, programmed by early-life nutrition, limits storage of lipids in adipose tissue, causing lipotoxicity and insulin resistance and thus increasing susceptibility to metabolic disease.

Metabolic aspects of insulin resistance in individuals born small for gestational age.

Numerous studies have shown an association between low weight at birth and being born small for gestational age (SGA) on the one hand and risk of developing insulin resistance and type 2 diabetes on the other. Our studies in twins have indicated a non-genetic age-dependent origin of insulin resistance and type 2 diabetes associated with being born SGA. In order to gain insight into the molecular metabolic defects and mechanisms linking SGA with insulin resistance and type 2 diabetes, we performed a series of experiments in young and elderly twins, and, in particular, in young men (aged 19-23 years) with a weight at birth at term in the lowest 10th percentile with no family history of diabetes. The control group included age-matched men with birth weights at term in the upper normal range. While body mass index and waist-to-hip ratios were similar in the individuals born SGA and controls, dual-energy X-ray absorptiometry studies documented a higher degree of abdominal obesity in the men who had a low weight at birth. Using the gold standard hyperinsulinaemic-euglycaemic clamp technique combined with glucose tracers and studies of forearm glucose uptake, we found an impairment of insulin-stimulated glycolytic flux and reduced forearm (muscle) glucose uptake in the face of normal whole-body glucose uptake. In addition, we found a significantly decreased insulin secretion rate during oral glucose ingestion after correction for insulin action (disposition index), a paradoxical enhanced insulin suppression of hepatic glucose production and lower fasting plasma glycerol levels, suggesting impaired lipolysis. Finally, analysis of skeletal muscle biopsies showed reduced muscle expression of several key proteins involved in insulin signalling and glucose transport, including protein kinase C-zeta, the two subunits of phosphoinositol 3-kinase (i.e., p85alpha and p110beta) and the insulin-sensitive glucose transporter, Glut-4, in individuals of low birth weight. In conclusion, being born SGA and of low birth weight is associated with type 2 diabetes in a non-genetic manner, and programming of muscle insulin action and signalling represents an early mechanism responsible for this association.

Decreased protein levels of key insulin signalling molecules in adipose tissue from young men with a low birthweight: potential link to increased risk of diabetes?

AIMS/HYPOTHESIS: Individuals with low birthweight are at increased risk of type 2 diabetes mellitus. However, the underlying molecular mechanisms are unknown. Previously we have shown that low birthweight is associated with changes in muscle insulin signalling proteins. Here we determined whether low birthweight is associated with changes in insulin signalling proteins in adipose tissue. METHODS: Men (age 23 years) with either a low (bottom 10th percentile) (n = 17) or a normal (50th-90th percentile) (n = 17) birthweight were recruited from the Danish Medical Birth Registry and subcutaneous adipose biopsies were taken. RESULTS: Between the two groups there was no difference in protein level of the insulin receptor, protein kinase C zeta, glycogen synthase kinase-3 (GSK3) alpha, GSK3 beta, protein kinase B alpha and beta, peroxisome proliferative activated receptor gamma coactivator 1 or Src-homology-2-containing protein. However, the levels of GLUT4 (also known as solute carrier family 2 [facilitated glucose transporter], member 4 [SLC2A4]) (52 +/- 10.9% reduction, p < 0.01), p85alpha subunit of phosphoinositide 3-kinase (PI3K) (45 +/- 9% reduction, p < 0.01), p110ss subunit of PI3K (48 +/- 17% reduction, p = 0.06) and IRS1 (59 +/- 24% reduction, p < 0.05) were reduced in men of low birthweight. CONCLUSIONS/INTERPRETATION: These findings show that low birthweight is associated with reduced levels of adipose insulin signalling proteins, thus providing a potential molecular framework to explain why people with low birthweight are at increased risk of developing type 2 diabetes. These differences precede the development of diabetes and thus may help predict disease risk.

No effect of taurine on platelet aggregation in men with a predisposition to type 2 diabetes mellitus.

Any diet therapy that potentially could affect platelet function would also influence the initiation of atherosclerotic plaque formation which is an important complication of diabetes mellitus eventually resulting in myocardial infarction and stroke. Blood platelets are rich in taurine, and it has been shown that taurine inhibits platelet aggregation in healthy subjects. The purpose was to examine the effect of taurine supplementation on platelet aggregation in high-risk subjects with a positive family history of T2DM. Twenty healthy men were included in a double-blinded, randomized, crossover study, receiving daily supplementation of 1.5 g taurine or placebo for two 8-week periods. Subjects were overweight and first-degree relatives of T2DM patients. At the end of each treatment, fasting blood samples for assessment of platelet aggregation was drawn. Platelet aggregation was induced by ADP. Plasma taurine concentration was significantly greater after taurine intervention compared to placebo (131.4+/-61.7 vs. 38.9+/-6.7 micromol/l, P<0.0001). There was no difference in the threshold level for complete platelet aggregation induced by ADP in vivo between placebo and taurine intervention (placebo 3.86+/-2.21 vs. taurine 3.86+/-3.25 micromol/l). Supplementation with 1.5 g of taurine for 8 weeks had no effect on platelet aggregation in overweight prediabetic men.

Study of the high-performance liquid chromatographic separation of reducing sugars, applied to the determination of lactose in milk.

The loss of reducing sugars by formation of Schiff bases on amino-bonded silica or on dynamically coated amino-silica columns was investigated at two column temperatures. Depending on the type, age and temperature of the column, these losses were in the range of 0-100%. A dimethylamino-bonded silica column did not cause loss of reducing sugars, but the retention of sugars was too weak to allow separation. The analysis of reducing sugars can be carried out on diol-modified silica with diisopropylethylamine in the eluent to enhance mutarotation. It is also possible to use a cation-exchange resin (Ca2+) column, equipped with a pre-column packed with a mixed-bed ion-exchange to remove interfering salts and acids. In combination with an acetate-acetonitrile sample clean-up, this method results in coefficients of variation of less than 1% for the determination of lactose in skim-milk.