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.     

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.     

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.     

Gender differences in Saudi patients with obstructive sleep apnea

Obstructive sleep apnea (OSA) remains under-recognized in women possibly due to differences in clinical presentation, difference in tolerance to symptoms, and rate of usage and referral to sleep services. No reports have addressed OSA in women in the Middle Eastern (Arab) population. Therefore, we conducted this study to assess the differences in demographics, clinical presentation, and polysomnographic (PSG) findings between Saudi women and men diagnosed to have (OSA). The study group comprised 191 consecutive Saudi women and 193 consecutive men who were referred to the Sleep Disorders Centre and were found by in-laboratory PSG to have OSA. Demographic and clinical data were obtained by personal interviews. Women were significantly older than men (53.9 and 43.0 years, respectively; p < 0.001). Similarly, their body mass index was significantly higher than men (p < 0.001). Insomnia was more common among women (39.8%) compared to men (25.9%; p = 0.005). Other sleep symptoms including witnessed apnea, and excessive daytime sleepiness did not show any statistical difference between the two groups. Women were more likely than men to be diagnosed with hypothyroidism, diabetes, hypertension, cardiac disease, and asthma. Apnea–hypopnea index (AHI) was statistically higher in men compared to women; however, most of apnea/hypopnea events in women occurred during rapid eye movement sleep, and the mean duration of hypopnea and apnea was significantly lower in women (p = 0.004). Sleep efficiency was lower in women (71.5% vs. 77.7%) in men (p < 0.001). The desaturation index was higher in men (p = 0.01), but no difference was found in lowest SaO₂ or time with SaO₂ less than 90%. The present study showed important clinical and PSG differences between Saudi women and men with OSA. Clinicians need to be aware of these differences when assessing women for the possibility of OSA as they may be symptomatic at a lower AHI and have significant comorbid conditions that can be adversely affected if their OSA was not timely managed.     

Variants in KCNQ1 are associated with susceptibility to type 2 diabetes in the population of mainland China

Aims/hypothesis  Two recent genome-wide association studies have identified several novel type 2 diabetes susceptibility variants in intron 15 of the KCNQ1 gene. We aimed to evaluate the effects of the variants in KCNQ1 on type 2 diabetes and metabolic traits in the population of mainland China. Methods  Three candidate single nucleotide polymorphisms were genotyped in 1,912 individuals with type 2 diabetes and 2,041 normal controls using the ligase detection reaction method. Results  We confirmed the association of KCNQ1 with type 2 diabetes in the population of mainland China. Allele frequency ORs of the three single nucleotide polymorphisms (SNPs) were: rs2237892 (OR 1.19, 95% CI 1.08–1.31, p = 3.0 × 10⁻⁴); rs2237895 (OR 1.20, 95% CI 1.09–1.32, p = 1.9 × 10⁻⁴); and rs2237897 (OR 1.24, 95% CI 1.13–1.36, p = 3.9 × 10⁻⁵). We also found a significant difference in the distribution of the global haplotypes between the type 2 diabetes group and the normal control group (p = 2.6 × 10⁻⁵). In addition, in the control group SNP rs2237892 was marginally associated with increasing fasting plasma glucose and SNPs rs2237892 and rs2237897 were associated with HbA_1c. Furthermore, for all three variants, homozygous carriers of the diabetes-associated allele had significantly decreased BMI and waist circumferences. Conclusions/interpretation  Our investigation confirmed the effects of KCNQ1 variants on type 2 diabetes risk in the Chinese population. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorised users. Y. Liu and D. Z. Zhou contributed equally to this study.     

Molecular detection of exercise-induced free radicals following ascorbate prophylaxis in type 1 diabetes mellitus: a randomised controlled trial

Aims/hypothesis  Patients with type 1 diabetes mellitus are more susceptible than healthy individuals to exercise-induced oxidative stress and vascular endothelial dysfunction, which has important implications for the progression of disease. Thus, in the present study, we designed a randomised double-blind, placebo-controlled trial to test the original hypothesis that oral prophylaxis with vitamin C attenuates rest and exercise-induced free radical-mediated lipid peroxidation in type 1 diabetes mellitus. Methods  All data were collected from hospitalised diabetic patients. The electron paramagnetic resonance spectroscopic detection of spin-trapped α-phenyl-tert-butylnitrone (PBN) adducts was combined with the use of supporting markers of lipid peroxidation and non-enzymatic antioxidants to assess exercise-induced oxidative stress in male patients with type 1 diabetes (HbA_1c 7.9 ± 1%, n = 12) and healthy controls (HbA_1c 4.6 ± 0.5%, n = 14). Following participant randomisation using numbers in a sealed envelope, venous blood samples were obtained at rest, after a maximal exercise challenge and before and 2 h after oral ingestion of 1 g ascorbate or placebo. Participants and lead investigators were blinded to the administration of either placebo or ascorbate treatments. Primary outcome was the difference in changes in free radicals following ascorbate ingestion. Results  Six diabetic patients and seven healthy control participants were randomised to each of the placebo and ascorbate groups. Diabetic patients (n = 12) exhibited an elevated concentration of PBN adducts (p < 0.05 vs healthy, n = 14), which were confirmed as secondary, lipid-derived oxygen-centred alkoxyl (RO·) radicals (a_nitrogen = 1.37 mT and aβ_hydrogen = 0.18 mT). Lipid hydroperoxides were also selectively elevated and associated with a depression of retinol and lycopene (p < 0.05 vs healthy). Vitamin C supplementation increased plasma vitamin C concentration to a similar degree in both groups (p < 0.05 vs pre-supplementation) and attenuated the exercise-induced oxidative stress response (p < 0.05 vs healthy). There were no selective treatment differences between groups in the primary outcome variable. Conclusions/interpretation  These findings are the first to suggest that oral vitamin C supplementation provides an effective prophylaxis against exercise-induced free radical-mediated lipid peroxidation in human diabetic blood. Clinical trials registration number: ISRCTN96164937 Funding: No external funding.     

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.     

Increased skeletal muscle ceramide level in men at risk of developing type 2 diabetes

Aims/hypothesis Intramyocellular lipids, including ceramide, a second messenger in the sphingomyelin signalling pathway, might contribute to the development of insulin resistance. The aim of our study was to assess parameters of the skeletal muscle sphingomyelin signalling pathway in men at risk of developing type 2 diabetes. Methods We studied 12 lean (BMI < 25 kg/m²) men without a family history of diabetes (control group), 12 lean male offspring of type 2 diabetic patients, and 21 men with overweight or obesity comprising 12 with NGT (obese-NGT) and nine with IGT (obese-IGT). A euglycaemic-hyperinsulinaemic clamp and a biopsy of vastus lateralis muscle were performed. Ceramide, sphingomyelin, sphinganine and sphingosine levels and sphingomyelinase and ceramidase activities were measured in muscle. Muscle diacylglycerol and triacylglycerol levels were estimated in a subgroup of 27 men (comprising men from all the above groups). Results Compared with the control group, the lean offspring of diabetic patients and the men with overweight or obesity showed lower insulin sensitivity (all p < 0.005) and a greater muscle ceramide level (all p < 0.01). The obese-IGT group had lower insulin sensitivity (p = 0.0018) and higher muscle ceramide (p = 0.0022) than the obese-NGT group. There was lower muscle sphingosine level and alkaline ceramidase activity in offspring of diabetic patients (p = 0.038 and p = 0.031, respectively) and higher sphinganine level in the obese-NGT (p = 0.049) and obese-IGT (p = 0.002) groups than in the control group. Muscle sphingomyelin was lower (p = 0.0028) and neutral sphingomyelinase activity was higher (p = 0.00079) in the obese-IGT than in the obese-NGT group. Muscle ceramide was related to insulin sensitivity independently of other muscle lipid fractions. Conclusions/interpretations Ceramide accumulates in muscle of men at risk of developing type 2 diabetes.     

Combined effects of single-nucleotide polymorphisms in GCK, GCKR, G6PC2 and MTNR1B on fasting plasma glucose and type 2 diabetes risk

Aims/hypothesis  Variation in fasting plasma glucose (FPG) within the normal range is a known risk factor for the development of type 2 diabetes. Several reports have shown that genetic variation in the genes for glucokinase (GCK), glucokinase regulatory protein (GCKR), islet-specific glucose 6 phosphatase catalytic subunit-related protein (G6PC2) and melatonin receptor type 1B (MTNR1B) is associated with FPG. In this study we examined whether these loci also contribute to type 2 diabetes susceptibility. Methods  A random selection from the Dutch New Hoorn Study was used for replication of the association with FGP (2,361 non-diabetic participants). For the genetic association study we extended the study sample with 2,628 participants with type 2 diabetes. Risk allele counting was used to calculate a four-gene risk allele score for each individual. Results  Variants of the GCK, G6PC2 and MTNR1B genes but not GCKR were associated with FPG (all, p ≤ 0.001; GCKR, p = 0.23). Combining these four genes in a risk allele score resulted in an increase of 0.05 mmol/l (0.04–0.07) per additional risk allele (p = 2 × 10⁻¹³). Furthermore, participants with less than three or more than five risk alleles showed significantly different type 2 diabetes susceptibility compared with the most common group with four risk alleles (OR 0.77 [0.65–0.93], p = 0.005 and OR 2.05 [1.50–2.80], p = 4 × 10⁻⁶ respectively). The age at diagnosis was also significantly associated with the number of risk alleles (p = 0.009). Conclusions  A combined risk allele score for single-nucleotide polymorphisms in four known FPG loci is significantly associated with FPG and HbA_1c in a Dutch population-based sample of non-diabetic participants. Carriers of low or high numbers of risk alleles show significantly different risks for type 2 diabetes compared with the reference group. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorised users.     

Associations between depressive symptoms and insulin resistance: The Hoorn Study

Aims/hypothesis The association between depression and insulin resistance has been investigated in only a few studies, with contradictory results reported. The aim of this study was to determine whether the association between symptoms of depression and insulin resistance varies across glucose tolerance status and between men and women.Subjects and methods Cross-sectional data from a population-based cohort study in Hoorn, a medium-sized town in the Netherlands, were analysed. The study sample consisted of 541 men and women aged 55–75 years, of whom 260 had NGT, 164 had IGT and 117 had established type 2 diabetes mellitus. Main outcome measures were insulin resistance defined by the homeostasis model assessment for insulin resistance (HOMA-IR) and symptoms of depression using the Centre for Epidemiologic Studies Depression Scale (CES-D).Results In the total sample, we found a weak positive correlation between the depressive symptoms CED-D scores and HOMA-IR scores (r _s = 0.156, p < 0.001). Even weaker associations were found in subjects with NGT (r _s = 0.041, p=0.509), in subjects with IGT (r _s = 0.112, p = 0.160) and in subjects with type 2 diabetes (r _s = 0.007, p = 0.942). The association between depressive symptoms and insulin resistance was similar for men and women.Conclusions/interpretation We found only weak associations between depressive symptoms and insulin resistance, which did not differ among different glucose metabolism subgroups or between men and women.     

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.     

Potential reno-protective effects of a gluten-free diet in type 1 diabetes

Aims/hypothesis  Coeliac disease is common in type 1 diabetes. It is managed with a gluten-free diet, characterised by foods low in AGEs. We hypothesised that this diet would lead to lower plasma AGEs and be associated with reduced albuminuria. Methods  From a single paediatric clinic, we recruited 21 children with type 1 diabetes and biopsy-proven coeliac disease, and 38 individuals with diabetes alone. The groups were matched for age, sex, duration of disease and metabolic control. Participants completed a detailed clinical and dietary history. Blood samples were taken for HbA_1c, coeliac serology, thyroid function, serum IgA levels and plasma AGEs, and urine samples were obtained for estimation of the albumin/creatinine ratio (ACR). Results  All the individuals with coeliac disease were asymptomatic, with negative transglutaminase antibodies. There were no significant differences between the groups in terms of age (14 years), sex (29% male), duration of diabetes (7 years), mean HbA_1c (8.3%), lipid levels or treatment regimens. However, children with diabetes and coeliac disease had twofold lower levels of urinary ACR than with those diabetes alone (p = 0.04). This was associated with lower levels of circulating AGEs (p = 0.03). These associations were independent of metabolic control, diabetes management and other potentially confounding variables, such as household exposure to cigarette smoke. Conclusions/interpretation  Adherence to a gluten-free diet may provide additional benefits for individuals with coeliac disease, and potentially those with type 1 diabetes.     

Impact of using a non-diabetes-specific risk calculator on eligibility for statin therapy in type 2 diabetes

Aims/hypothesis  The aim of this study was to investigate the impact of using a non-diabetes-specific cardiovascular disease (CVD) risk calculator to determine eligibility for statin therapy according to current UK National Institute for Health and Clinical Excellence (NICE) guidelines for those patients with type 2 diabetes who are at an increased risk of CVD (10 year risk ≥20%). Methods  The 10 year CVD risks were estimated using the UK Prospective Diabetes Study (UKPDS) Risk Engine and the Framingham equation for 4,025 patients enrolled in the Lipids in Diabetes Study who had established type 2 diabetes and LDL-cholesterol <4.1 mmol/l. Results  The mean (SD) age of the patients was 60.7 (8.6) years, blood pressure 141/83 (17/10) mmHg and the total cholesterol:HDL-cholesterol ratio was 3.9 (1.0). The median (interquartile range) diabetes duration was 6 (3–11) years and the HbA_1c level was 8.0% (7.2–9.0%). The cohort comprised 65% men, 91% whites, 4% Afro-Caribbeans, 5% Asian Indians and 15% current smokers. More patients were classified as being at high risk by the UKPDS Risk Engine (65%) than by the Framingham CVD equation (63%) (p < 0.0001). The Framingham CVD equation classified fewer men and people aged <50 years old as high risk (p < 0.0001). There was no difference between the UKPDS Risk Engine and Framingham classification of women at high risk (p = 0.834). Conclusions/interpretation  These results suggest that the use of Framingham-derived rather than UKPDS Risk Engine-derived CVD risk estimates would deny about one in 25 patients statin therapy when applying current NICE guidelines. Thus, under these guidelines the choice of CVD risk calculator is important when assessing CVD risk in patients with type 2 diabetes, particularly for the identification of the relatively small proportion of younger people who require statin therapy.     

The effect of bilio-pancreatic diversion on type 2 diabetes in patients with BMI <35?kg/m2

Aims/hypothesis  To aim of the study was to investigate the effect of bilio-pancreatic diversion (BPD) on type 2 diabetes in patients with BMI <35 kg/m². Methods  OGTTs were performed and anthropometric data were compared between five diabetes patients (BMI 27–33 kg/m²) following BPD and seven diabetes patients after a low-energy diet. Insulin secretion was computed by C-peptide deconvolution. A euglycaemic–hyperinsulinaemic clamp was performed only in the BPD group and the M value measured. Results  One month after BPD, fasting and 2 h post-OGTT glycaemia decreased from 15.22 ± 3.22 to 6.22 ± 0.51 mmol/l (p = 0.043), while insulin sensitivity increased significantly. No significant changes were observed in the low-energy diet group. Insulin secretion did not differ significantly after either intervention. Diabetes amelioration (change in HbA_1c level) was observed up to 18 months after BPD without pharmacological therapy. Conclusions/interpretation  BPD can achieve adequate control of type 2 diabetes also in patients with BMI <35 kg/m². The rapid postoperative remission of diabetes is primarily related to an improvement in insulin sensitivity.     

Diabetes,glycaemic control and mortality risk in patients on haemodialysis: the Japan Dialysis Outcomes and Practice Pattern Study

Aims/hypothesis There are few data on the target level of glycaemic control among patients with diabetes on haemodialysis. We investigated the impact of glycaemic control on mortality risk among diabetic patients on haemodialysis. Subjects and methods Data were analysed from the Dialysis Outcomes Practice Pattern Study (DOPPS) for randomly selected patients on haemodialysis in Japan. The diagnosis of diabetes at baseline and information on clinical events during follow-up were abstracted from the medical records. A Cox proportional hazards model was used to evaluate the association between presence or absence of diabetes, glycaemic control (HbA_1c quintiles) and mortality risk. Results Data from 1,569 patients with and 3,342 patients without diabetes on haemodialysis were analysed. Among patients on haemodialysis, those with diabetes had a higher mortality risk than those without (multivariable hazard ratio 1.37, 95% CI 1.08–1.74). Compared with those in the bottom quintile of HbA_1c level, the multivariable-adjusted hazard ratio for mortality was not increased in the bottom second to fourth quintiles of HbA_1c (HbA_1c 5.0–5.5% to 6.2–7.2%), but was significantly increased to 2.36 (95% CI 1.02–5.47) in the fifth quintile (HbA_1c ≥ 7.3%). The effect of poor glycaemic control did not statistically correlate with baseline mortality risk (p = 0.27). Conclusions/interpretation Among dialysis patients, poorer glycaemic control in those with diabetes was associated with higher mortality risk. This suggests a strong effect of poor glycaemic control above an HbA_1c level of about 7.3% on mortality risk, and that this effect does not appear to be influenced by baseline comorbidity status.     

Pioglitazone stimulates AMP-activated protein kinase signalling and increases the expression of genes involved in adiponectin signalling, mitochondrial function and fat oxidation in human skeletal muscle in vivo: a randomised trial

Aims/hypothesis  The molecular mechanisms by which thiazolidinediones improve insulin sensitivity in type 2 diabetes are not fully understood. We hypothesised that pioglitazone would activate the adenosine 5′-monophosphate-activated protein kinase (AMPK) pathway and increase the expression of genes involved in adiponectin signalling, NEFA oxidation and mitochondrial function in human skeletal muscle. Methods  A randomised, double-blind, parallel study was performed in 26 drug-naive type 2 diabetes patients treated with: (1) pioglitazone (n = 14) or (2) aggressive nutritional therapy (n = 12) to reduce HbA_1c to levels observed in the pioglitazone-treated group. Participants were assigned randomly to treatment using a table of random numbers. Before and after 6 months, patients reported to the Clinical Research Center of the Texas Diabetes Institute for a vastus lateralis muscle biopsy followed by a 180 min euglycaemic–hyperinsulinaemic (80 mU m⁻² min⁻¹) clamp. Results  All patients in the pioglitazone (n = 14) or nutritional therapy (n = 12) group were included in the analysis. Pioglitazone significantly increased plasma adiponectin concentration by 79% and reduced fasting plasma NEFA by 35% (both p < 0.01). Following pioglitazone, insulin-stimulated glucose disposal increased by 30% (p < 0.01), and muscle AMPK and acetyl-CoA carboxylase (ACC) phosphorylation increased by 38% and 53%, respectively (p < 0.05). Pioglitazone increased mRNA levels for adiponectin receptor 1 and 2 genes (ADIPOR1, ADIPOR2), peroxisome proliferator-activated receptor gamma, coactivator 1 gene (PPARGC1) and multiple genes involved in mitochondrial function and fat oxidation. Despite a similar reduction in HbA_1c and similar improvement in insulin sensitivity with nutritional therapy, there were no significant changes in muscle AMPK and ACC phosphorylation, or the expression of ADIPOR1, ADIPOR2, PPARGC1 and genes involved in mitochondrial function and fat oxidation. No adverse (or unexpected) effects or side effects were reported from the study. Conclusions/interpretations  Pioglitazone increases plasma adiponectin levels, stimulates muscle AMPK signalling and increases the expression of genes involved in adiponectin signalling, mitochondrial function and fat oxidation. These changes may represent an important cellular mechanism by which thiazolidinediones improve skeletal muscle insulin sensitivity. Trial registration: NCT 00816218 Funding: This trial was funded by National Institutes of Health Grant DK24092, VA Merit Award, GCRC Grant RR01346, Executive Research Committee Research Award from the University of Texas Health Science Center at San Antonio, American Diabetes Association Junior Faculty Award, American Heart Association National Scientist Development Grant, Takeda Pharmaceuticals North America Grant and Canadian Institute of Health Research Grant. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorised users.     

Hyperinsulinaemia during exercise does not suppress hepatic glycogen concentrations in patients with type 1 diabetes: a magnetic resonance spectroscopy study

Aims/hypothesis We compared in vivo changes in liver glycogen concentration during exercise between patients with type 1 diabetes and healthy volunteers. Methods We studied seven men with type 1 diabetes (mean ± SEM diabetes duration 10 ± 2 years, age 33 ± 3 years, BMI 24 ± 1 kg/m², HbA_1c 8.1 ± 0.2% and VO₂ peak 43 ± 2 ml [kg lean body mass]⁻¹ min⁻¹) and five non-diabetic controls (mean ± SEM age 30 ± 3 years, BMI 22 ± 1 kg/m², HbA_1c 5.4 ± 0.1% and VO₂ peak 52 ± 4 ml [kg lean body mass]⁻¹ min⁻¹, before and after a standardised breakfast and after three bouts (EX1, EX2, EX3) of 40 min of cycling at 60% VO₂ peak. ¹³C Magnetic resonance spectroscopy of liver glycogen was acquired in a 3.0 T magnet using a surface coil. Whole-body substrate oxidation was determined using indirect calorimetry. Results Blood glucose and serum insulin concentrations were significantly higher (p < 0.05) in the fasting state, during the postprandial period and during EX1 and EX2 in subjects with type 1 diabetes compared with controls. Serum insulin concentration was still different between groups during EX3 (p < 0.05), but blood glucose concentration was similar. There was no difference between groups in liver glycogen concentration before or after the three bouts of exercise, despite the relative hyperinsulinaemia in type 1 diabetes. There were also no differences in substrate oxidation rates between groups. Conclusions/interpretation In patients with type 1 diabetes, hyperinsulinaemic and hyperglycaemic conditions during moderate exercise did not suppress hepatic glycogen concentrations. These findings do not support the hypothesis that exercise-induced hypoglycaemia in patients with type 1 diabetes is due to suppression of hepatic glycogen mobilisation. K. Chokkalingam and K. Tsintzas contributed equally to this study.