Reducing glycaemic variability in type 1 diabetes self-management with a continuous glucose monitoring system based on wired enzyme technology

Aims/hypothesis  This study was designed to investigate the use and impact of a continuous glucose monitoring system (the FreeStyle Navigator) under home-use conditions in the self-management of type 1 diabetes. Methods  A 20 day masked phase, when real-time data and alarms were not available, was compared with a subsequent 40 day unmasked phase for a number of specified measures of glycaemic variability. HbA_1c (measured by DCA 2000) and a hypoglycaemia fear survey were recorded at the start and end of the study. Results  The study included 48 patients with type 1 diabetes (mean age 35.7 ± 10.9, range 18–61 years; diabetes duration 17.0 ± 9.5 years). Two patients did not complete the study for personal reasons. Comparing masked (all 20 days) and unmasked (last 20 days) phases, the following reductions were seen: time outside euglycaemia from 11.0 to 9.5 h/day (p = 0.002); glucose SD from 3.5 to 3.2 mmol/l (p < 0.001); hyperglycaemic time (>10.0 mmol/l) from 10.3 to 8.9 h/day (p = 0.0035); mean amplitude of glycaemic excursions (peak to nadir) down by 10% (p < 0.001); high blood glucose index down by 18% (p = 0.0014); and glycaemic risk assessment diabetes equation score down by 12% (p = 0.0013). Hypoglycaemic time (<3.9 mmol/l) decreased from 0.70 to 0.64 h/day without statistical significance (p > 0.05). Mean HbA_1c fell from 7.6 ± 1.1% at baseline to 7.1 ± 1.1% (p < 0.001). In the hypoglycaemia fear survey, the patients tended to take less snacks at night-time after wearing the sensor. Conclusions/interpretation  Home use of a continuous glucose monitoring system has a positive effect on the self-management of diabetes. Thus, continuous glucose monitoring may be a useful tool to decrease glycaemic variability.     

Plasma sex steroid hormones and risk of developing type 2 diabetes in women: a prospective study

Aims/hypothesis Prospective data directly investigating the role of endogenous sex hormones in diabetes risk have been scant, particularly in women. We aimed to examine comprehensively plasma sex hormones in connection with risk of developing type 2 diabetes in postmenopausal women. Methods We conducted a prospective, nested case–control study of plasma oestradiol, testosterone and dehydroepiandrosterone sulfate and risk of type 2 diabetes in a cohort of women health professionals with a mean age of 60.3 and 12.2 years since menopause. Among women not using hormone therapy and free of baseline cardiovascular disease, cancer and diabetes, 359 incident cases of type 2 diabetes were matched with 359 controls during an average follow-up of 10 years. Results Oestradiol and testosterone were each strongly and positively associated with risk of type 2 diabetes. After adjustment for BMI, family history, lifestyle and reproductive variables, the multivariable relative risks (95% CI) comparing the highest vs lowest quintile were 12.6 (2.83–56.3) for total oestradiol (p = 0.002 for trend), 13.1 (4.18–40.8) for free oestradiol (p < 0.001 for trend), 4.15 (1.21–14.2) for total testosterone (p = 0.019 for trend) and 14.8 (4.44–49.2) for free testosterone (p < 0.001 for trend). These associations remained robust after adjusting and accounting for other metabolic syndrome components and baseline HbA_1c levels. Conclusions/interpretation In postmenopausal women, higher plasma levels of oestradiol and testosterone were strongly and prospectively related to increased risk of developing type 2 diabetes. These prospective data indicate that endogenous levels of sex hormones may play important roles in the pathogenesis of type 2 diabetes. ClinicalTrials.gov ID no.: NCT00000479.     

Polymorphisms in the gene encoding the voltage-dependent Ca<Superscript>2+</Superscript> channel Ca<Subscript>V</Subscript>2.3 (<Emphasis Type="Italic">CACNA1E</Emphasis>) are associated with type 2 diabetes and impaired insulin secretion

Aims/hypothesis Glucose-stimulated insulin secretion is dependent on the electrical activity of beta cells; hence, genes encoding beta cell ion channels are potential candidate genes for type 2 diabetes. The gene encoding the voltage-dependent Ca²⁺ channel Ca_V2.3 (CACNA1E), telomeric to a region that has shown suggestive linkage to type 2 diabetes (1q21-q25), has been ascribed a role for second-phase insulin secretion. Methods Based upon the genotyping of 52 haplotype tagging single nucleotide polymorphisms (SNPs) in a type 2 diabetes case–control sample (n = 1,467), we selected five SNPs that were nominally associated with type 2 diabetes and genotyped them in the following groups (1) a new case–control sample of 6,570 individuals from Sweden; (2) 2,293 individuals from the Botnia prospective cohort; and (3) 935 individuals with insulin secretion data from an IVGTT. Results The rs679931 TT genotype was associated with (1) an increased risk of type 2 diabetes in the Botnia case–control sample [odds ratio (OR) 1.4, 95% CI 1.0–2.0, p = 0.06] and in the replication sample (OR 1.2, 95% CI 1.0–1.5, p = 0.01 one-tailed), with a combined OR of 1.3 (95% CI 1.1–1.5, p = 0.004 two-tailed); (2) reduced insulin secretion [insulinogenic index at 30 min p = 0.02, disposition index (D _I) p = 0.03] in control participants during an OGTT; (3) reduced second-phase insulin secretion at 30 min (p = 0.04) and 60 min (p = 0.02) during an IVGTT; and (4) reduced D _I over time in the Botnia prospective cohort (p = 0.05). Conclusions/interpretation We conclude that genetic variation in the CACNA1E gene contributes to an increased risk of the development of type 2 diabetes by reducing insulin secretion. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorised users.     

HbA1c measured in stored erythrocytes and mortality rate among middle-aged and older women

Aims/hypothesis Diabetes is known to increase mortality rate, but the degree to which mild hyperglycaemia may be associated with the risk of death is uncertain. We examined the association between HbA_1c measured in stored erythrocytes and mortality rate in women with and without diabetes. Methods We conducted a cohort study of 27,210 women ≥ 45 years old with no history of cardiovascular disease or cancer who participated in the Women’s Health Study, a randomised trial of vitamin E and aspirin. Results Over a median of 10 years of follow-up, 706 women died. Proportional hazards models adjusted for age, smoking, hypertension, blood lipids, exercise, postmenopausal hormone use, multivitamin use and C-reactive protein were used to estimate the relative risk of mortality. Among women without a diagnosis of diabetes and HbA_1c <5.60%, those in the top quintile (HbA_1c 5.19–5.59%) had a relative risk of mortality of 1.28 (95% CI 0.98–1.69, p value for linear trend = 0.14) compared with those with HbA_1c 2.27–4.79%. Women with HbA_1c 5.60–5.99% and no diagnosis of diabetes had a 54% increased risk of mortality (95% CI 1–136%) compared with those with HbA_1c 2.27–4.79%. HbA_1c was significantly associated with mortality across the range 4.50–7.00% (p value for linear trend = 0.02); a test of deviation from linearity was not statistically significant (p = 0.67). Diabetic women had more than twice the mortality risk of non-diabetic women. Conclusions/interpretation This study provides further evidence that chronic mild hyperglycaemia, even in the absence of diagnosed diabetes, is associated with increased risk of mortality. ClinicalTrials.gov ID no.: NCT00000479     

Intensive insulin therapy improves endothelial function and microvascular reactivity in young people with type 1 diabetes

Aims/hypothesis Macrovascular disease is an important cause of the increased morbidity and mortality rates associated with type 1 diabetes, and this vascular impairment begins in childhood. The aim of this study was to determine whether introducing intensive diabetes management [intensive insulin therapy (IIT) and ‘Sweet Talk’ text-messaging support] produces measurable improvements in endothelial function. Methods One hundred and twenty-six patients fulfilled the eligibility criteria (type 1 diabetes for >1 year; on conventional insulin therapy (CIT); aged between 8 and 18 years), of whom 92 enrolled. Patients were randomised to group 1, CIT only (n = 28); group 2, CIT and Sweet Talk (n = 33); or group 3, IIT and Sweet Talk (n = 31). Vascular assessments (including measures of endothelial damage, activation, dysfunction and oxidative stress) and HbA_1c were performed at baseline and repeated after 12 months of the study. Results Glycaemic control deteriorated in patients on CIT, but improved significantly in patients allocated to IIT (p = 0.007). IIT was associated with significantly greater improvements in E-selectin (p < 0.0001) than CIT (group 1, p = 0.026 and group 2, p = 0.053). Vascular responses to acetylcholine improved in patients on IIT (p = 0.017), but not in patients receiving CIT. These changes were all independent of HbA_1c level. Conclusions/interpretation IIT appears to be associated with improvements in vascular markers, independently of changes in HbA_1c, suggesting that IIT may confer vascular protection in addition to improving glycaemic control.     

Addition of vildagliptin to insulin improves glycaemic control in type 2 diabetes

Aims/hypothesis Type 2 diabetes is difficult to manage in patients with a long history of disease requiring insulin therapy. Moreover, addition of most currently available oral antidiabetic agents increases the risk of hypoglycaemia. Vildagliptin is a dipeptidyl peptidase-IV inhibitor, which improves glycaemic control by increasing pancreatic beta cell responsiveness to glucose and suppressing inappropriate glucagon secretion. This study assessed the efficacy and tolerability of vildagliptin added to insulin therapy in patients with type 2 diabetes. Materials and methods This was a multicentre, 24-week, double-blind, randomised, placebo-controlled, parallel-group study in patients with type 2 diabetes that was inadequately controlled (HbA_1c = 7.5–11%) by insulin. Patients received vildagliptin (n = 144; 50 mg twice daily) or placebo (n = 152) while continuing insulin therapy. Results Baseline HbA_1c averaged 8.4 ± 0.1% in both groups. The adjusted mean change from baseline to endpoint (AMΔ) in HbA_1c was −0.5 ± 0.1% and −0.2 ± 0.1% in patients receiving vildagliptin or placebo, respectively, with a significant between-treatment difference (p = 0.01). In patients aged ≥65 years, the AMΔ HbA_1c was −0.7 ± 0.1% in the vildagliptin group vs −0.1 ± 0.1% in the placebo group (p < 0.001). The incidence of adverse events was similar in the vildagliptin (81.3%) and placebo (82.9%) groups. However, hypoglycaemic events were less common (p < 0.001) and less severe (p < 0.05) in patients receiving vildagliptin than in those receiving placebo. Conclusions/interpretation Vildagliptin decreases HbA_1c in patients whose type 2 diabetes is poorly controlled with high doses of insulin. Addition of vildagliptin to insulin therapy is also associated with reduced confirmed and severe hypoglycaemia. ClinicalTrials.gov ID no.: NCT 00099931. Electronic supplementary material The online version of this article (doi:) contains a complete list of investigators which is available to authorised users.     

Mean blood glucose compared with HbA<Subscript>1c</Subscript> in the prediction of cardiovascular disease in patients with type 1 diabetes

Aims/hypothesis It is not known whether mean blood glucose (MBG) predicts the risk of macrovascular complications in diabetes any differently from HbA_1c. In this study we therefore analysed data from the Diabetes Control and Complications Trial (DCCT) to assess the relationship between MBG, HbA_1c and glucose variability with regard to the risk of cardiovascular disease in patients with type 1 diabetes. Methods Pre- and postprandial seven-point glucose profiles were collected quarterly during the DCCT in 1441 individuals. The relationship between time to first cardiovascular event and MBG, HbA_1c and daily SD of blood glucose was assessed by Cox regression after adjusting for the known risk factors of macrovascular disease and the treatment groups of the patients. Results Cox regression showed MBG to be predictive of a cardiovascular event (p = 0.019), but not HbA_1c (p = 0.858). A rise of 1 mmol/l in MBG was associated with an 11% rise in cardiovascular risk. MBG remained highly predictive (p = 0.015) even after adjustment for HbA_1c values and glucose variability. Conclusions/interpretation This study has shown that during the DCCT MBG was a better predictor of the macrovascular complications of type 1 diabetes than HbA_1c. It indicates that the cardiovascular risk associated with hyperglycaemia appeared within the time period of the study and that blood glucose rather than HbA_1c may be the preferred means of assessing this risk.     

Impaired short-term blood pressure regulation and autonomic dysbalance in children with type 1 diabetes mellitus

Aims Because reduction in baroreceptor sensitivity (BRS) has been associated with hypertension in the normal population and with increased cardiovascular morbidity and mortality in patients with diabetes mellitus, we measured BRS in a patient cohort of children with type 1 diabetes mellitus. Methods Two hundred and eight children (150 patients with type 1 diabetes mellitus, mean age 13.9 ± 2.8 years, 70 boys, mean HbA_1c 7.8 ± 1.4%; and 58 healthy controls, mean age 14.1 ± 3.1 years, 32 boys) were studied. BRS and heart rate variability (HRV) were analysed from a short-time ECG and BP recording using the sequence method (BRS) and the frequency domain method (HRV). Results There were 111 of 150 patients (74%) and 5 of 58 controls (8.6%) that showed impaired BRS. Mean BRS differed significantly between patients and controls (18.4 ± 7.2 vs 25.8 ± 8.2 ms/mm, p < 0.001). BRS correlated inversely with systolic BP (r = −0.23, p = 0.009) and was related to diabetes duration (r = −0.194, p = 0.027). Analysis of HRV showed greater sympathetic and less parasympathetic influence in patients than in controls (low frequency/high frequency ratio 1.3 ± 0.8 vs 0.9 ± 0.6, p < 0.05); the low frequency/high frequency ratio was inversely correlated with BRS (r = −0.28, p = 0.001). Conclusions/interpretation Diabetic children show reduced BRS. In our patient group, the single risk factor for this finding was found to be the disease duration. The degree of BRS impairment was related to the degree of autonomic dysbalance. R. Dalla Pozza and S. Bechtold contributed equally to this study.     

Coffee consumption and risk of cardiovascular events and all-cause mortality among women with type 2 diabetes

Aims/hypothesis  Coffee has been linked to both beneficial and harmful health effects, but data on its relationship with cardiovascular disease and mortality in patients with type 2 diabetes are sparse. Methods  This was a prospective cohort study including 7,170 women with diagnosed type 2 diabetes but free of cardiovascular disease or cancer at baseline. Coffee consumption was assessed in 1980 and then every 2–4 years using validated questionnaires. A total of 658 incident cardiovascular events (434 coronary heart disease and 224 stroke) and 734 deaths from all causes were documented between 1980 and 2004. Results  After adjustment for age, smoking and other cardiovascular risk factors, the relative risks were 0.76 (95% CI 0.50–1.14) for cardiovascular diseases (p trend = 0.09) and 0.80 (95% CI 0.55–1.14) for all-cause mortality (p trend = 0.05) for the consumption of ≥4 cups/day of caffeinated coffee compared with non-drinkers. Similarly, multivariable RRs were 0.96 (95% CI 0.66–1.38) for cardiovascular diseases (p trend = 0.84) and 0.76 (95% CI 0.54–1.07) for all-cause mortality (p trend = 0.08) for the consumption of ≥2 cups/day of decaffeinated coffee compared with non-drinkers. Higher decaffeinated coffee consumption was associated with lower concentrations of HbA_1c (6.2% for ≥2 cups/day versus 6.7% for <1 cup/month; p trend = 0.02). Conclusions  These data provide evidence that habitual coffee consumption is not associated with increased risk of cardiovascular diseases or premature mortality among diabetic women. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorised users.     

Relationship between glyco-oxidation, antioxidant status and microalbuminuria in type 2 diabetic patients

Aims/hypothesis  This study examined the relationship, if any, between glucose-induced oxidative stress, antioxidant status and microalbuminuria in patients with type 2 diabetes. Methods  The study involved 99 consecutive type 2 diabetic patients (57 men, 42 women). Patients with persistent microalbuminuria were identified and the following variables evaluated: fasting plasma glucose, HbA_1c, malonyldialdehyde (MDA), pentosidine, AGE, the total radical-trapping antioxidant parameter (TRAP), vitamin E, creatinine, estimated GFR and lipid profile. Results  Patients were divided into two groups, i.e. 37 individuals without microalbuminuria (AER <20 μg/min) and 62 with microalbuminuria (AER ≥20 μg/min). The following variables were significantly higher in patients with microalbuminuria than in those without microalbuminuria (mean ± SD): fasting plasma glucose 9.41 ± 2.88 vs 8.19 ± 1.93 mmol/l, p < 0.05; HbA_1c 7.97 ± 1.51 vs 7.39 ± 1.03%, p < 0.05; MDA 1.18 ± 0.35 vs 1.02 ± 0.29 μmol/l, p < 0.05; pentosidine 98.5 ± 24.6 vs 82.9 ± 20.9 pmol/ml, p < 0.005; and AGE 13.2 ± 4.8 vs 10.6 ± 3.8 μg/mg protein, p < 0.01. However, vitamin E and TRAP did not differ between the two groups. Serum creatinine values and estimated GFR were similar in the two groups. Only in patients with microalbuminuria were significant linear correlations seen between AER and both oxidation (HbA_1c r = 0.33, p < 0.01; MDA r = 0.59, p < 0.001; pentosidine r = 0.48, p < 0.001; and AGE r = 0.44, p < 0.001) and antioxidation variables (vitamin E r = −0.55, p < 0.001; TRAP r = −0.49, p < 0.001). Considering all variables together, multiple regression revealed a correlation between microalbuminuria and vitamin E, TRAP, HbA_1c and MDA, but not pentosidine or AGE. Conclusions/interpretation  Our data suggest that microalbuminuria in type 2 diabetic patients might be promoted by an insufficient counter-regulation of the antioxidant system in the event of increased glyco-oxidation/glycation.     

Children and adolescents with type 1 diabetes eat a more atherosclerosis-prone diet than healthy control subjects

Aims/hypothesis We evaluated how well the diet of Norwegian children and adolescents with type 1 diabetes fulfils the Nordic and European dietary recommendations, focusing on parameters affecting prevention of atherosclerosis. We also compared the diet of this patient group with that of healthy same-age control subjects. Materials and methods A total of 177 children and adolescents with type 1 diabetes (9–10-year-olds, 12–13-year-olds) and 1,809 healthy same-age control subjects recorded their food intake for 4 days in precoded food diaries. Results In children and adolescents with type 1 diabetes the percentage of energy (E%) from fat (33–35 E%) and saturated fat (14–15 E%) was higher than recommended for that group. Furthermore their intake of fibre was lower (16–19 g/day) than current recommendations. There were no differences in energy intake between diabetic subjects and healthy control subjects. Percentage of energy from fat (mean difference: 3.4 E%, p < 0.001) and saturated fat (mean difference: 1.0 E%, p < 0.001) was significantly higher among diabetic subjects than control subjects. Intake of fruits and vegetables was low (210 g/day) compared with recommendations, both in the diabetic and control subjects. Conclusions/interpretation Diabetic children and adolescents had a high intake of energy from saturated fat and low intake of fibre, fruits and vegetables, which could increase the risk of development of atherosclerosis. This study supports the idea that nutritional guidance in the treatment of children and adolescents with type 1 diabetes should be more focused, especially with regard to intake of fibre, fruits and vegetables and to quality and quantity of fat intake.     

Survival analysis of patients with dermatomyositis and polymyositis

To estimate the mortality rate and identify factors predicting survival in patients with polymyositis (PM) and dermatomyositis (DM). The medical records of 192 PM/DM patients who were treated at Chang Gung Memorial Hospital from 1999 through 2008 were retrospectively reviewed. The Taiwan National Death Registry (1999–2008) was used to obtain their survival status. Thirty-one (16.1%) of the 192 patients with PM/DM had an associated malignancy; 41 (21.4%) had interstitial lung disease (ILD). During the follow-up period, 55 (28.6%) patients died and the overall cumulative survival rate was 79.3% at 1 year, 75.7% at 2 years, 69.9% at 5 years, and 66.2% at 10 years. In univariate analysis, older age at PM/DM onset, anemia, thrombocytopenia, leukopenia, diabetes mellitus, ILD, cancer, and non-use of azathioprine were associated with higher mortality (p = 0.0172, 0.0484, <0.0001, 0.0008, 0.0001, 0.0036, 0.0010, and 0.0019, respectively). In multivariate Cox regression analysis, thrombocytopenia (hazard ratio [HR] 4.94, 95% confidence interval [CI] 2.60–9.37, p < 0.0001), diabetes mellitus (HR 2.57, 95% CI 1.38–4.80, p < 0.0001), cancer (HR 2.30, 95% CI 1.26–4.22, p = 0.0030), and ILD (HR 1.98, 95% CI 1.11–3.51, p = 0.0182) were positively associated with mortality. Use of azathioprine (HR 0.35, 95% CI 0.16–0.74, p = 0.0064) was negatively associated with mortality. This study confirmed the high mortality rate (28.6%) in PM/DM patients. Survival time was significantly reduced in patients with thrombocytopenia, diabetes mellitus, ILD, and cancer patients than in those without these conditions.     

Polymorphisms in <Emphasis Type="Italic">AHI1</Emphasis> are not associated with type 2 diabetes or related phenotypes in Danes: non-replication of a genome-wide association result

Aims/hypothesis A genome-wide association study recently identified an association between common variants, rs1535435 and rs9494266, in the AHI1 gene and type 2 diabetes. The aim of the present study was to investigate the putative association between these polymorphisms and type 2 diabetes or type 2 diabetes-related metabolic traits in Danish individuals. Methods The previously associated polymorphisms were genotyped in the population-based Inter99 cohort (n = 6162), the Danish ADDITION study (n = 8428), a population-based sample of young healthy participants (n = 377) and in additional type 2 diabetes (n = 2107) and glucose-tolerant participants (n = 483) using Taqman allelic discrimination. The case–control study involved 4,104 type 2 diabetic patients and 5,050 glucose-tolerant control participants. Type 2 diabetes-related traits were investigated in 17,521 individuals. Results rs1535435 and rs9494266 were not associated with type 2 diabetes. Odds ratios (OR) were OR_add 1.0 (95% C.I. 0.9–1.2; p _add = 0.7) and OR_add 1.1 (0.9–1.2; p _add = 0.4), respectively, a finding supported by meta-analyses: OR_add 1.0 (0.9–1.1; p _add = 0.6) and OR_add 1.0 (0.9–1.1; p _add = 0.6), respectively. Neither rs1535435 nor rs9494266 were consistently associated with any of the tested type 2 diabetes-related metabolic traits. Conclusions/interpretation Data from large samples of Danish individuals do not support a role for AHI1 rs1535435 nor rs9494266 as major type 2 diabetes variants. This study highlights the importance of independent and well-powered replication studies of the recent genome-wide association scans before a locus is robustly validated as being associated with type 2 diabetes. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorised users.     

Early administration of the glucose-dependent insulinotropic polypeptide receptor antagonist (Pro3)GIP prevents the development of diabetes and related metabolic abnormalities associated with genetically inherited obesity in ob/ob mice

Aims/hypothesis Ablation of gastric inhibitory polypeptide (GIP) receptor action is reported to protect against obesity and associated metabolic abnormalities. The aim of this study was to use prediabetic ob/ob mice to examine whether 60 days of chemical GIP receptor ablation with (Pro³)GIP is able to counter the development of genetic obesity-related diabetes. Materials and methods Young (5–7 weeks) ob/ob mice received once daily i.p. injections of either saline vehicle or (Pro³)GIP (25 nmol kg⁻¹ day⁻¹) over a 60 day period. Food intake, body weight and circulating glucose and insulin were measured at frequent intervals. At 60 days, glucose tolerance, response to native GIP, postprandial responses, insulin sensitivity, HbA_1c, circulating hormones and plasma lipids were assessed. Results Body weight and food intake in (Pro³)GIP-treated mice did not differ from ob/ob controls. GIP receptor blockade significantly improved non-fasting glucose (p < 0.001), HbA_1c (p < 0.05), glucose tolerance (p < 0.001), meal tolerance (p < 0.001) and insulin sensitivity (p < 0.05). Remarkably, (Pro³)GIP treatment prevented the age-related development of diabetes, as none of these parameters differed significantly between treated ob/ob mice and normal age-matched lean controls. Circulating levels of glucagon, corticosterone, adiponectin and total cholesterol were unchanged by (Pro³)GIP, while levels of triacylglycerol, LDL-cholesterol and resistin were decreased (p < 0.05) compared with those in control ob/ob mice. Plasma and pancreatic insulin concentrations were generally lower after (Pro³)GIP treatment than in control ob/ob mice (p < 0.01), but plasma insulin levels remained substantially raised (p < 0.001) compared with those observed in lean controls. Conclusions/interpretation These data indicate that sustained GIP receptor antagonism provides an effective means of preventing the development of many of the metabolic abnormalities of obesity-driven diabetes.     

High prevalence of low plasma thiamine concentration in diabetes linked to a marker of vascular disease

Aims/hypothesis To assess thiamine status by analysis of plasma, erythrocytes and urine in type 1 and type 2 diabetic patients and links to markers of vascular dysfunction. Methods Diabetic patients (26 type 1 and 48 type 2) with and without microalbuminuria and 20 normal healthy control volunteers were recruited. Erythrocyte activity of transketolase, the concentrations of thiamine and related phosphorylated metabolites in plasma, erythrocytes and urine, and markers of metabolic control and vascular dysfunction were determined. Results Plasma thiamine concentration was decreased 76% in type 1 diabetic patients and 75% in type 2 diabetic patients: normal volunteers 64.1 (95% CI 58.5–69.7) nmol/l, type 1 diabetes 15.3 (95% CI 11.5–19.1) nmol/l, p < 0.001, and type 2 diabetes 16.3 (95% CI 13.0–9.6) nmol/l, p < 0.001. Renal clearance of thiamine was increased 24-fold in type 1 diabetic patients and 16-fold in type 2 diabetic patients. Plasma thiamine concentration correlated negatively with renal clearance of thiamine (r = −0.531, p < 0.001) and fractional excretion of thiamine (r = −0.616, p < 0.001). Erythrocyte transketolase activity correlated negatively with urinary albumin excretion (r = −0.232, p < 0.05). Thiamine transporter protein contents of erythrocyte membranes of type 1 and type 2 diabetic patients were increased. Plasma thiamine concentration and urinary excretion of thiamine correlated negatively with soluble vascular adhesion molecule-1 (r = −0.246, p < 0.05, and −0.311, p < 0.01, respectively). Conclusions/interpretation Low plasma thiamine concentration is prevalent in patients with type 1 and type 2 diabetes, associated with increased thiamine clearance. The conventional assessment of thiamine status was masked by increased thiamine transporter content of erythrocytes.     

Impaired in vivo mitochondrial function but similar intramyocellular lipid content in patients with type 2 diabetes mellitus and BMI-matched control subjects

Aims/hypothesis Mitochondrial dysfunction and increased intramyocellular lipid (IMCL) content have both been implicated in the development of insulin resistance and type 2 diabetes mellitus, but the relative contributions of these two factors in the aetiology of diabetes are unknown. As obesity is an independent determinant of IMCL content, we examined mitochondrial function and IMCL content in overweight type 2 diabetes patients and BMI-matched normoglycaemic controls. Methods In 12 overweight type 2 diabetes patients and nine controls with similar BMI (29.4 ± 1 and 29.3 ± 0.9 kg/m² respectively) in vivo mitochondrial function was determined by measuring phosphocreatine recovery half-time (PCr half-time) immediately after exercise, using phosphorus-31 magnetic resonance spectroscopy. IMCL content was determined by proton magnetic resonance spectroscopic imaging and insulin sensitivity was measured with a hyperinsulinaemic–euglycaemic clamp. Results The PCr half-time was 45% longer in diabetic patients compared with controls (27.3 ± 3.5 vs 18.7 ± 0.9 s, p < 0.05), whereas IMCL content was similar (1.37 ± 0.30 vs 1.25 ± 0.22% of the water resonance), and insulin sensitivity was reduced in type 2 diabetes patients (26.0 ± 2.2 vs 18.9 ± 2.3 μmol min⁻¹ kg⁻¹, p < 0.05 [all mean ± SEM]). PCr half-time correlated positively with fasting plasma glucose (r ² = 0.42, p < 0.01) and HbA_1c (r ² = 0.48, p < 0.05) in diabetic patients. Conclusions/interpretation The finding that in vivo mitochondrial function is decreased in type 2 diabetes patients compared with controls whereas IMCL content is similar suggests that low mitochondrial function is more strongly associated with insulin resistance and type 2 diabetes than a high IMCL content per se. Whether low mitochondrial function is a cause or consequence of the disease remains to be investigated.     

Increased serum levels of advanced glycation endproducts predict total, cardiovascular and coronary mortality in women with type 2 diabetes: a population-based 18 year follow-up study

Aims/hypothesis AGEs, modification products formed by glycation or glycoxidation of proteins and lipids, have been linked to premature atherosclerosis in patients with diabetes. We investigated whether increased serum levels of AGEs predict total, cardiovascular (CVD) or CHD mortality in a population-based study. Subjects and methods Serum levels of AGEs were determined by immunoassay in a random sample of 874 Finnish diabetic study participants (488 men, 386 women), aged 45–64 years. These participants were followed for 18 years for total, CVD and CHD mortality. Results Multivariate Cox regression models revealed that serum levels of AGEs were significantly associated with total (p = 0.002) and CVD mortality (p = 0.021) in women, but not in men. Serum levels of AGEs in the highest sex-specific quartile predicted all-cause (hazards ratio [HR] 1.51; 95% confidence intervals [CI], 1.14–1.99; p = 0.004), CVD (HR 1.56; 95% CI 1.12–2.19; p = 0.009), and CHD (HR 1.68; 95% CI 1.11–2.52; p = 0.013) mortality in women, even after adjustment for confounding factors, including high-sensitivity C-reactive protein. Conclusions/interpretation Increased serum levels of AGEs predict total and CVD mortality in women with type 2 diabetes. B. K. Kilhovd and A. Juutilainen contributed equally to this study.     

HbA<Subscript>1c</Subscript> as a risk factor for heart failure in persons with diabetes: the Atherosclerosis Risk in Communities (ARIC) study

Aims/hypothesis  Heart failure (HF) incidence in diabetes in both the presence and absence of CHD is rising. Prospective population-based studies can help describe the relationship between HbA_1c, a measure of glycaemia control, and HF risk. Methods  We studied the incidence of HF hospitalisation or death among 1,827 participants in the Atherosclerosis Risk in Communities (ARIC) study with diabetes and no evidence of HF at baseline. Cox proportional hazard models included age, sex, race, education, health insurance status, alcohol consumption, BMI and WHR, and major CHD risk factors (BP level and medications, LDL- and HDL-cholesterol levels, and smoking). Results  In this population of persons with diabetes, crude HF incidence rates per 1,000 person-years were lower in the absence of CHD (incidence rate 15.5 for CHD-negative vs 56.4 for CHD-positive, p<0.001). The adjusted HR of HF for each 1% higher HbA_1c was 1.17 (95% CI 1.11–1.25) for the non-CHD group and 1.20 (95% CI 1.04–1.40) for the CHD group. When the analysis was limited to HF cases which occurred in the absence of prevalent or incident CHD (during follow-up) the adjusted HR remained 1.20 (95% CI 1.11–1.29). Conclusions/interpretations  These data suggest HbA_1c is an independent risk factor for incident HF in persons with diabetes with and without CHD. Long-term clinical trials of tight glycaemic control should quantify the impact of different treatment regimens on HF risk reduction.     

Fetal growth is increased by maternal type 1 diabetes and HLA DR4-related gene interactions

Aims/hypothesis Intrauterine growth in non-diabetic pregnancies is reported to be influenced by type 1 diabetes susceptibility genes. In particular, the high-risk HLA DR4_DQB1*0302 haplotype is associated with increased birthweight. The aim of this study was to determine whether HLA DR4 was associated with increased birthweight in a maternal diabetes environment and whether effects persisted during early childhood. Subjects and methods Birthweight and gestational age were obtained in singleton births from mothers with type 1 diabetes (n = 1161) or whose fathers or siblings have type 1 diabetes (n = 872). Weight and height at ages 2 and 5 years were obtained from paediatric records. Data were adjusted for (gestational) age and sex and expressed as percentiles of German reference data. HLA DR typing was obtained for all children and 1090 children also had insulin gene (INS) variable number of tandem repeats (VNTR) typing. Results Maternal type 1 diabetes was associated with increased birthweight, gestational age and birthweight percentiles (all p < 0.0001). In children of mothers with type 1 diabetes, birthweight percentile was further related to maternal HbA_1c during pregnancy (r = 0.26; p < 0.0001) and was independently increased if children had HLA DR4 alleles (76th vs 64th percentile; p < 0.0001). HLA DR4 was not associated with birthweight in children of non-diabetic mothers. Birthweight was not associated with INS VNTR genotypes. High birthweight, but not HLA DR4 was associated with increased weight and BMI at ages 2 and 5 years (p < 0.0001). Conclusions/interpretation Our findings are consistent with the hypothesis that a diabetic intrauterine environment interacts with gene(s) marked by the type 1 diabetes susceptibility HLA DR4 alleles to increase fetal growth. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorised users.