Conformation-dependent GAD65 autoantibodies in diabetes

Aims/hypothesis. Conformation-dependent autoantibodies directed against GAD65 are markers of Type 1 diabetes. In this study we aimed to determine whether the substitution of GAD65 with GAD67 amino acids would affect the binding of conformation-dependent GAD65 autoantibodies. Methods. We used PCR-based site-directed mutagenesis to generate a series of mutated GAD65 cDNA constructs in which specific GAD65 coding sequences for regions of the protein critical for autoantibody binding were replaced with GAD67 coding sequences. Results. The introduction of a point mutation at position 517, substituting glutamic acid with proline, markedly reduced the binding of disease-associated GAD65 antibodies. The binding of GAD65 antibodies to the E517P mutant was reduced in the sera of all newly diagnosed Type 1 diabetes patients (n=85) by a mean of 72% (p<0.0001) compared with binding to wild-type GAD65. Patients with latent autoimmune diabetes in adults (n=24) showed a similar reduction in binding (79% reduction, p<0.0001). First-degree relatives who subsequently progressed to Type 1 diabetes (n=12) showed a reduction in binding of 80% compared with a reduction of only 65% among relatives who had not progressed to disease (n=38; p=0.025). In healthy GAD65Ab-positive individuals who did not progress to diabetes during a 9-year follow-up period (n=51), binding to GAD65-E517P was reduced by only 28% compared with binding to wild-type GAD65. Conclusions/interpretation. Differences in autoantibody binding to wild-type GAD65 versus GAD65-E517P may provide predictive information about Type 1 diabetes risk beyond that provided by the presence or absence of GAD65 autoantibodies. Lack of binding to mutant GAD65-E517P defines GAD65-positive individuals who are at higher risk of developing diabetes

Screening for type 2 diabetes: Do screen-detected cases fare better?

Aims/hypothesis We aimed to investigate whether diabetes cases detected through screening have better health outcomes than clinically detected cases in a population-based cohort of adults who were eligible to be screened for diabetes at 10 year intervals. Methods The Västerbotten Intervention Programme is a community- and individual-based public health programme in Västerbotten County, Sweden. Residents are invited to clinical examinations that include screening for diabetes by OGTTs at age 30, 40, 50 and 60 years (individuals eligible for screening, n = 142,037). Between 1992 and 2013, we identified 1024 screen-detected cases and 8642 clinically detected cases of diabetes using registry data. Clinically detected individuals were either prior screening participants (n = 4506) or people who did not participate in screening (non-participants, n = 4136). Study individuals with diabetes were followed from date of detection until end of follow-up, emigration, death or incident cardiovascular disease (CVD), renal disease or retinopathy event, and compared using Cox proportional hazard regression adjusted for calendar time, age at detection, year of detection, sex and socioeconomic status. Results The average age at diabetes diagnosis was 4.6 years lower for screen-detected individuals compared with clinically detected individuals. Overall, those who were clinically detected had worse health outcomes than those who were screen-detected (HR for all-cause mortality 2.07 [95% CI 1.63, 2.62]). Compared with screen-detected study individuals, all-cause mortality was higher for clinically detected individuals who were screening non-participants (HR 2.31 [95% CI 1.82, 2.94]) than for those clinically detected who were prior screening participants (HR 1.70 [95% CI 1.32, 2.18]). Estimates followed a similar pattern for CVD, renal disease and retinopathy. Conclusions/interpretation Individuals with screen-detected diabetes were diagnosed earlier and appeared to fare better than those who were clinically detected with regard to all-cause mortality, CVD, renal disease and retinopathy. How much of these associations can be explained by earlier treatment because of screening rather than healthy user bias, lead time bias and length time bias warrants further investigation.This work was supported by the Medical Research Council (MC_UU_12015/4), the Swedish Council for Working Life and Social Research (FAS 2006_1512) and the Swedish Research Council (2006-21576-36119-666). The VIP is financed by Västerbotten County Council. ALF is supported by the Raymond and Beverly Sackler Foundation through Churchill College, Cambridge

Change in lifestyle behaviors and diabetes risk: evidence from a population-based cohort study with 10 year follow-up

Abstract Background Promoting positive changes in lifestyle behavior in the whole population may be a feasible and effective approach to reducing type 2 diabetes burden, but the impact of population shifts of modifiable risk factors remains unclear. Currently most of the evidence on modifiable lifestyle behavior and type 2 diabetes risk on a population level comes from studies of between-individual differences. The objective of the study was to investigate the association and potential impact on disease burden for within-individual change in lifestyle behavior and diabetes risk. Methods Population-based prospective cohort study of 35,680 participants aged 30–50 at baseline in 1990–2003 in Västerbotten County, Sweden (follow-up until 2013). Five self-reported modifiable lifestyle behaviors (tobacco use, physical activity, alcohol intake, dietary fiber intake and dietary fat intake) were measured at baseline and 10 year follow-up. Lifestyle behaviors were studied separately, and combined in a score. Incident diabetes was detected by oral glucose tolerance tests. Multivariate logistic regression models and population attributable fractions (PAF) were used to analyze the association between change in lifestyle behavior between baseline and 10 year follow-up, and risk of incident diabetes. Results Incident diabetes was detected in 1,184 (3.3%) participants at 10 year follow-up. There was a reduced diabetes risk associated with increase in dietary fiber intake, odds ratio (OR) 0.79 (95% confidence interval (CI) 0.66, 0.96) for increase of at least one unit standard deviation (3.0 g/1,000 kcal) of the baseline distribution, PAF 16.0% (95% CI 4.2, 26.4%). Increase in the lifestyle behavior score was associated with reduced diabetes risk, OR 0.92 (95% CI 0.85, 0.99) per unit increase of the score. Conclusions These results support a causal link between lifestyle behavior and type 2 diabetes incidence. A small shift in lifestyle behaviors, in particular intake of dietary fiber, has the potential to reduce diabetes burden in the population and might be a suitable target for public health intervention

How the Cathedral Embraced the Bazaar, and the Bazaar Became a Cathedral

Peer reviewe

associations between general and abdominal adiposity and mortality in individuals with diabetes mellitus

Individuals with diabetes mellitus are advised to achieve a healthy weight to prevent complications. However, fat mass distribution has hardly been investigated as a risk factor for diabetes complications. The authors studied associations between body mass index, waist circumference, waist/hip ratio, and waist/height ratio and mortality among individuals with diabetes mellitus. Within the European Prospective Investigation into Cancer and Nutrition, a subcohort was defined as 5,435 individuals with a confirmed self-report of diabetes mellitus at baseline in 1992-2000. Participants were aged 57.3 (standard deviation, 6.3) years, 54% were men, the median diabetes duration was 4.6 (interquartile range, 2.0-9.8) years, and 22% of the participants used insulin. Body mass index, as indicator of general obesity, was not associated with higher mortality, whereas all measurements of abdominal obesity showed a positive association. Associations generally were slightly weaker in women. The strongest association was observed for waist/height ratio: In the fifth quintile, the hazard rate ratio was 1.88 (95% confidence interval: 1.33, 2.65) for men and 2.46 (95% confidence interval: 1.46, 4.14) for women. Measurements of abdominal, but not general, adiposity were associated with higher mortality in diabetic individuals. The waist/height ratio showed the strongest association. Respective indicators might be investigated in risk prediction models

Detailed Investigation of the Role of Common and Low-Frequency WFS1 Variants in Type 2 Diabetes Risk

OBJECTIVE: Wolfram syndrome 1 (WFS1) single nucleotide polymorphisms (SNPs) are associated with risk of type 2 diabetes. In this study we aimed to refine this association and investigate the role of low-frequency WFS1 variants in type 2 diabetes risk. RESEARCH DESIGN AND METHODS: For fine-mapping, we sequenced WFS1 exons, splice junctions, and conserved noncoding sequences in samples from 24 type 2 diabetic case and 68 control subjects, selected tagging SNPs, and genotyped these in 959 U.K. type 2 diabetic case and 1,386 control subjects. The same genomic regions were sequenced in samples from 1,235 type 2 diabetic case and 1,668 control subjects to compare the frequency of rarer variants between case and control subjects. RESULTS: Of 31 tagging SNPs, the strongest associated was the previously untested 3' untranslated region rs1046320 (P = 0.008); odds ratio 0.84 and P = 6.59 x 10(-7) on further replication in 3,753 case and 4,198 control subjects. High correlation between rs1046320 and the original strongest SNP (rs10010131) (r2 = 0.92) meant that we could not differentiate between their effects in our samples. There was no difference in the cumulative frequency of 82 rare (minor allele frequency [MAF] 100,000) or studies in ethnically diverse populations. Low frequency variants in WFS1 are unlikely to have a large impact on type 2 diabetes risk in white U.K. populations, highlighting the complexities of undertaking association studies with low-frequency variants identified by resequencing

Replication of the association between variants in WFS1 and risk of type 2 diabetes in European populations

Aims/hypothesis: Mutations at the Wolframin encoding gene, WFS1, cause Wolfram syndrome, a rare neurological condition. Associations between single nucleotide polymorphisms (SNPs) at WFS1 and type 2 diabetes have recently been reported. In the present study, we sought to replicate those associations in a northern Swedish case-control study for type 2 diabetes. We also meta-analyzed published and previously unpublished data from Sweden, Finland and France to obtain updated summary effect estimates. Methods: Four WFS1 SNPs (rs10010131, rs6446482, rs752854, rs734312 [R611H]) were genotyped in a type 2 diabetes case-control study (N=1,296/1,412) of Swedish adults. Logistic regression was used to assess the association between each WFS1 SNP and type 2 diabetes, following adjustment for age, sex, and body mass index. We then performed a meta-analysis of 11 studies of type 2 diabetes, comprising up to 14,139 cases and 16,109 controls, to obtain a summary effect estimate for the WFS1 variants. Results: In the northern Swedish study, the minor allele at rs752854 was associated with reduced type 2 diabetes risk (OR=0.85; 95% CI=0.75-0.96; p=0.010). Borderline statistical associations were observed for the remaining SNPs. The meta-analysis of the four independent replication studies for SNP rs10010131, or its proxy variants, showed evidence for statistical association (OR=0.87; 95% CI=0.82-0.93; p=4.5×10−5). In an updated meta-analysis of all 11 studies, comprising 14,139 cases and 16,109 controls, strong evidence for statistical association was also observed (OR=0.89; 95% CI=0.86-0.92; p=4.9×10−11). Conclusion: In this study of WFS1 gene variants and type 2 diabetes risk, we have replicated the previously reported associations between SNPs at this locus and risk of type 2 diabetes

Alcoholic beverage preference and diabetes incidence across Europe the Consortium on Health and Ageing Network of Cohorts in Europe and the United States (CHANCES) project

It is unknown if wine, beer and spirit intake lead to a similar association with diabetes. We studied the association between alcoholic beverage preference and type 2 diabetes incidence in persons who reported to consume alcohol.Ten European cohort studies from the Consortium on Health and Ageing: Network of Cohorts in Europe and the United States were included, comprising participant data of 62 458 adults who reported alcohol consumption at baseline. Diabetes incidence was based on documented and/or self-reported diagnosis during follow-up. Preference was defined when ⩾70% of total alcohol consumed was either beer, wine or spirits. Adjusted hazard ratios (HRs) were computed using Cox proportional hazard regression. Single-cohort HRs were pooled by random-effects meta-analysis.Beer, wine or spirit preference was not related to diabetes risk compared with having no preference. The pooled HRs were HR 1.06 (95% confidence interval (CI) 0.93, 1.20) for beer, HR 0.99 (95% CI 0.88, 1.11) for wine, and HR 1.19 (95% CI 0.97, 1.46) for spirit preference. Absolute wine intake, adjusted for total alcohol, was associated with a lower diabetes risk: pooled HR per 6 g/day was 0.96 (95% CI 0.93, 0.99). A spirit preference was related to a higher diabetes risk in those with a higher body mass index, in men and women separately, but not after excluding persons with prevalent diseases.This large individual-level meta-analysis among persons who reported alcohol consumption revealed that the preference for beer, wine, and spirits was similarly associated with diabetes incidence compared with having no preference