Latent autoimmune diabetes in adults (LADA) should be less latent

'Latent autoimmune diabetes in adults' (LADA) is the term coined to describe adults who have a slowly progressive form of autoimmune or type 1 diabetes that can be treated initially without insulin injections. The diagnosis of LADA is currently based on three clinical criteria: (1) adult age at onset of diabetes; (2) the presence of circulating islet autoantibodies, which distinguishes LADA from type 2 diabetes; and (3) insulin independence at diagnosis, which distinguishes LADA from classic type 1 diabetes. The prevalence of LADA in adults presenting with non-insulin-requiring diabetes is approximately 10%. Recognition of LADA expands the concept and prevalence of autoimmune diabetes, but LADA remains poorly understood at both a clinical and research level. In this perspective, we review the nomenclature, diagnostic criteria, genetics, pathology and therapy of LADA, to arrive at recommendations that might advance knowledge and management of this form of diabetes.

The link between family history and risk of type 2 diabetes is not explained by anthropometric, lifestyle or genetic risk factors: the EPIC-InterAct study

AIMS/HYPOTHESIS

Although a family history of type 2 diabetes is a strong risk factor for the disease, the factors mediating this excess risk are poorly understood. In the InterAct case-cohort study, we investigated the association between a family history of diabetes among different family members and the incidence of type 2 diabetes, as well as the extent to which genetic, anthropometric and lifestyle risk factors mediated this association.

METHODS

A total of 13,869 individuals (including 6,168 incident cases of type 2 diabetes) had family history data available, and 6,887 individuals had complete data on all mediators. Country-specific Prentice-weighted Cox models were fitted within country, and HRs were combined using random effects meta-analysis. Lifestyle and anthropometric measurements were performed at baseline, and a genetic risk score comprising 35 polymorphisms associated with type 2 diabetes was created.

RESULTS

A family history of type 2 diabetes was associated with a higher incidence of the condition (HR 2.72, 95% CI 2.48, 2.99). Adjustment for established risk factors including BMI and waist circumference only modestly attenuated this association (HR 2.44, 95% CI 2.03, 2.95); the genetic score alone explained only 2% of the family history-associated risk of type 2 diabetes. The greatest risk of type 2 diabetes was observed in those with a biparental history of type 2 diabetes (HR 5.14, 95% CI 3.74, 7.07) and those whose parents had been diagnosed with diabetes at a younger age (<50 years; HR 4.69, 95% CI 3.35, 6.58), an effect largely confined to a maternal family history.

CONCLUSIONS/INTERPRETATION

Prominent lifestyle, anthropometric and genetic risk factors explained only a marginal proportion of the excess risk associated with family history, highlighting the fact that family history remains a strong, independent and easily assessed risk factor for type 2 diabetes. Discovering factors that will explain the association of family history with type 2 diabetes risk will provide important insight into the aetiology of type 2 diabetes.

Fruit and vegetable intake and type 2 diabetes: EPIC-InterAct prospective study and meta-analysis

Fruit and vegetable intake (FVI) may reduce the risk of type 2 diabetes (T2D), but the epidemiological evidence is inconclusive. The aim of this study is to examine the prospective association of FVI with T2D and conduct an updated meta-analysis. In the European Prospective Investigation into Cancer-InterAct (EPIC-InterAct) prospective case-cohort study nested within eight European countries, a representative sample of 16,154 participants and 12,403 incident cases of T2D were identified from 340,234 individuals with 3.99 million person-years of follow-up. For the meta-analysis we identified prospective studies on FVI and T2D risk by systematic searches of MEDLINE and EMBASE until April 2011. In EPIC-InterAct, estimated FVI by dietary questionnaires varied more than twofold between countries. In adjusted analyses the hazard ratio (95% confidence interval) comparing the highest with lowest quartile of reported intake was 0.90 (0.80-1.01) for FVI; 0.89 (0.76-1.04) for fruit and 0.94 (0.84-1.05) for vegetables. Among FV subtypes, only root vegetables were inversely associated with diabetes 0.87 (0.77-0.99). In meta-analysis using pooled data from five studies including EPIC-InterAct, comparing the highest with lowest category for FVI was associated with a lower relative risk of diabetes (0.93 (0.87-1.00)). Fruit or vegetables separately were not associated with diabetes. Among FV subtypes, only green leafy vegetable (GLV) intake (relative risk: 0.84 (0.74-0.94)) was inversely associated with diabetes. Subtypes of vegetables, such as root vegetables or GLVs may be beneficial for the prevention of diabetes, while total FVI may exert a weaker overall effect.

Consumption of sweet beverages and type 2 diabetes incidence in European adults: results from EPIC-InterAct

AIMS/HYPOTHESIS

Consumption of sugar-sweetened beverages has been shown, largely in American populations, to increase type 2 diabetes incidence. We aimed to evaluate the association of consumption of sweet beverages (juices and nectars, sugar-sweetened soft drinks and artificially sweetened soft drinks) with type 2 diabetes incidence in European adults.

METHODS

We established a case-cohort study including 12,403 incident type 2 diabetes cases and a stratified subcohort of 16,154 participants selected from eight European cohorts participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. After exclusions, the final sample size included 11,684 incident cases and a subcohort of 15,374 participants. Cox proportional hazards regression models (modified for the case-cohort design) and random-effects meta-analyses were used to estimate the association between sweet beverage consumption (obtained from validated dietary questionnaires) and type 2 diabetes incidence.

RESULTS

In adjusted models, one 336 g (12 oz) daily increment in sugar-sweetened and artificially sweetened soft drink consumption was associated with HRs for type 2 diabetes of 1.22 (95% CI 1.09, 1.38) and 1.52 (95% CI 1.26, 1.83), respectively. After further adjustment for energy intake and BMI, the association of sugar-sweetened soft drinks with type 2 diabetes persisted (HR 1.18, 95% CI 1.06, 1.32), but the association of artificially sweetened soft drinks became statistically not significant (HR 1.11, 95% CI 0.95, 1.31). Juice and nectar consumption was not associated with type 2 diabetes incidence.

CONCLUSIONS/INTERPRETATION

This study corroborates the association between increased incidence of type 2 diabetes and high consumption of sugar-sweetened soft drinks in European adults.

Design and cohort description of the InterAct Project: an examination of the interaction of genetic and lifestyle factors on the incidence of type 2 diabetes in the EPIC Study

AIMS/HYPOTHESIS

Studying gene-lifestyle interaction may help to identify lifestyle factors that modify genetic susceptibility and uncover genetic loci exerting important subgroup effects. Adequately powered studies with prospective, unbiased, standardised assessment of key behavioural factors for gene-lifestyle studies are lacking. This case-cohort study aims to investigate how genetic and potentially modifiable lifestyle and behavioural factors, particularly diet and physical activity, interact in their influence on the risk of developing type 2 diabetes.

METHODS

Incident cases of type 2 diabetes occurring in European Prospective Investigation into Cancer and Nutrition (EPIC) cohorts between 1991 and 2007 from eight of the ten EPIC countries were ascertained and verified. Prentice-weighted Cox regression and random-effects meta-analyses were used to investigate differences in diabetes incidence by age and sex.

RESULTS

A total of 12,403 verified incident cases of type 2 diabetes occurred during 3.99 million person-years of follow-up of 340,234 EPIC participants eligible for InterAct. We defined a centre-stratified subcohort of 16,154 individuals for comparative analyses. Individuals with incident diabetes who were randomly selected into the subcohort (n = 778) were included as cases in the analyses. All prevalent diabetes cases were excluded from the study. InterAct cases were followed-up for an average of 6.9 years; 49.7% were men. Mean baseline age and age at diagnosis were 55.6 and 62.5 years, mean BMI and waist circumference values were 29.4 kg/m(2) and 102.7 cm in men, and 30.1 kg/m(2) and 92.8 cm in women, respectively. Risk of type 2 diabetes increased linearly with age, with an overall HR of 1.56 (95% CI 1.48-1.64) for a 10 year age difference, adjusted for sex. A male excess in the risk of incident diabetes was consistently observed across all countries, with a pooled HR of 1.51 (95% CI 1.39-1.64), adjusted for age.

CONCLUSIONS/INTERPRETATION

InterAct is a large, well-powered, prospective study that will inform our understanding of the interplay between genes and lifestyle factors on the risk of type 2 diabetes development.

Association between dietary meat consumption and incident type 2 diabetes: the EPIC-InterAct study

AIMS/HYPOTHESIS

A diet rich in meat has been reported to contribute to the risk of type 2 diabetes. The present study aims to investigate the association between meat consumption and incident type 2 diabetes in the EPIC-InterAct study, a large prospective case-cohort study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) study.

METHODS

During 11.7 years of follow-up, 12,403 incident cases of type 2 diabetes were identified among 340,234 adults from eight European countries. A centre-stratified random subsample of 16,835 individuals was selected in order to perform a case-cohort design. Prentice-weighted Cox regression analyses were used to estimate HR and 95% CI for incident diabetes according to meat consumption.

RESULTS

Overall, multivariate analyses showed significant positive associations with incident type 2 diabetes for increasing consumption of total meat (50 g increments: HR 1.08; 95% CI 1.05, 1.12), red meat (HR 1.08; 95% CI 1.03, 1.13) and processed meat (HR 1.12; 95% CI 1.05, 1.19), and a borderline positive association with meat iron intake. Effect modifications by sex and class of BMI were observed. In men, the results of the overall analyses were confirmed. In women, the association with total and red meat persisted, although attenuated, while an association with poultry consumption also emerged (HR 1.20; 95% CI 1.07, 1.34). These associations were not evident among obese participants.

CONCLUSIONS/INTERPRETATION

This prospective study confirms a positive association between high consumption of total and red meat and incident type 2 diabetes in a large cohort of European adults.

Diabetes mellitus, insulin treatment, diabetes duration, and risk of biliary tract cancer and hepatocellular carcinoma in a European cohort

BACKGROUND

Evidence on associations between self-reported diabetes mellitus, diabetes duration, age at diabetes diagnosis, insulin treatment, and risk of biliary tract cancer (BTC) and hepatocellular carcinoma (HCC), independent of general and abdominal obesity is scarce.

PATIENTS AND METHODS

We conducted a prospective analysis in the EPIC-cohort study among 363 426 participants with self-reported diabetes data. Multivariable adjusted relative risks and 95% confidence intervals were estimated from Cox regression models. In a nested case-control subset, analyses were carried out in HCV/HBV-negative individuals.

RESULTS

During 8.5 years of follow-up, 204 BTC cases [including 75 gallbladder cancer (GBC) cases], and 176 HCC cases were identified. Independent of body mass index and waist-to-height ratio diabetes status was associated with higher risk of BTC and HCC [1.77 (1.00-3.13) and 2.17 (1.36-3.47)]. For BTC, the risk seemed to be higher in participants with shorter diabetes duration and those not treated with insulin. Regarding cancer subsites, diabetes was only associated with GBC [2.72 (1.17-6.31)]. The risk for HCC was particularly higher in participants treated with insulin. The results were not appreciably different in HCV/HBV-negative individuals.

CONCLUSION(S)

This study supports the hypothesis that diabetes is a risk factor for BTC (particularly GBC) and HCC. Further research is required to establish whether diabetes treatment or duration is associated with these cancers.

Exome sequencing-driven discovery of coding polymorphisms associated with common metabolic phenotypes

AIMS/HYPOTHESIS

Human complex metabolic traits are in part regulated by genetic determinants. Here we applied exome sequencing to identify novel associations of coding polymorphisms at minor allele frequencies (MAFs) >1% with common metabolic phenotypes.

METHODS

The study comprised three stages. We performed medium-depth (8×) whole exome sequencing in 1,000 cases with type 2 diabetes, BMI >27.5 kg/m(2) and hypertension and in 1,000 controls (stage 1). We selected 16,192 polymorphisms nominally associated (p < 0.05) with case-control status, from four selected annotation categories or from loci reported to associate with metabolic traits. These variants were genotyped in 15,989 Danes to search for association with 12 metabolic phenotypes (stage 2). In stage 3, polymorphisms showing potential associations were genotyped in a further 63,896 Europeans.

RESULTS

Exome sequencing identified 70,182 polymorphisms with MAF >1%. In stage 2 we identified 51 potential associations with one or more of eight metabolic phenotypes covered by 45 unique polymorphisms. In meta-analyses of stage 2 and stage 3 results, we demonstrated robust associations for coding polymorphisms in CD300LG (fasting HDL-cholesterol: MAF 3.5%, p = 8.5 × 10(-14)), COBLL1 (type 2 diabetes: MAF 12.5%, OR 0.88, p = 1.2 × 10(-11)) and MACF1 (type 2 diabetes: MAF 23.4%, OR 1.10, p = 8.2 × 10(-10)).

CONCLUSIONS/INTERPRETATION

We applied exome sequencing as a basis for finding genetic determinants of metabolic traits and show the existence of low-frequency and common coding polymorphisms with impact on common metabolic traits. Based on our study, coding polymorphisms with MAF above 1% do not seem to have particularly high effect sizes on the measured metabolic traits.

Prevalence and incidence of diabetes mellitus: a nationwide population-based pharmaco-epidemiological study in Sweden

AIM

To investigate the changes in prevalence and incidence of pharmacologically and non-pharmacologically treated diabetes in Sweden during 2005 to 2013.

METHODS

We obtained data on gender, date of birth and pharmacologically and non-pharmacologically treated diabetes from national registers for all Swedish residents.

RESULTS

During the study period a total of 240 871 new cases of pharmacologically treated diabetes was found. The age-standardized incidence during the follow-up was 4.34 and 3.16 per 1000 individuals in men and women, respectively. A decreasing time trend in incidence for men of 0.6% per year (0.994, 95% CI 0.989-0.999) and for women of 0.7% per year (0.993, 95% CI 0.986-0.999) was observed. The age-standardized prevalence increased from 41.9 and 29.9 per 1000 in 2005/2006 to 50.8 and 34.6 in 2012/2013 in men and women, respectively. This corresponds to an annually increasing time trend for both men (1.024, 95% CI 1.022-1.027) and women (1.019, 95% CI 1.016-1.021). The total age-standardized prevalence of pharmacologically and non-pharmacologically treated diabetes (2012) was 46.9 per 1000 (55.6 for men and 38.8 for women). This corresponds to an annually increasing time trend (2010-2012) for both men (1.017, 95% CI 1.013-1.021) and women (1.012, 95% CI 1.008-1.016).

CONCLUSIONS

The prevalence of pharmacologically treated diabetes increased moderately during 8 years of follow-up, while the incidence decreased modestly. This is in contrast to the results reported by most other studies. The total prevalence of diabetes (both pharmacologically and non-pharmacologically treated) in Sweden is relatively low, from a global viewpoint.

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

AIMS/HYPOTHESIS

Mutations at the gene encoding wolframin (WFS1) cause Wolfram syndrome, a rare neurological condition. Associations between single nucleotide polymorphisms (SNPs) at WFS1 and type 2 diabetes have recently been reported. Thus, our aim was to replicate those associations in a northern Swedish case-control study of type 2 diabetes. We also performed a meta-analysis of published and previously unpublished data from Sweden, Finland and France, to obtain updated summary effect estimates.

METHODS

Four WFS1 SNPs (rs10010131, rs6446482, rs752854 and rs734312 [H611R]) 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 BMI. We then performed a meta-analysis of 11 studies of type 2 diabetes, comprising up to 14,139 patients 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 [odds ratio (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 and correlated variants showed evidence for statistical association (OR 0.87, 95% CI 0.82-0.93, p=4.5 x 10(-5)). In an updated meta-analysis of all 11 studies, strong evidence of statistical association was also observed (OR 0.89, 95% CI 0.86-0.92; p=4.9 x 10(-11)).

CONCLUSIONS/INTERPRETATION

In this study of WFS1 variants and type 2 diabetes risk, we have replicated the previously reported associations between SNPs at this locus and the risk of type 2 diabetes.

Alcohol consumption and risk of type 2 diabetes in European men and women: influence of beverage type and body size The EPIC-InterAct study

OBJECTIVE

To investigate the association between alcohol consumption and type 2 diabetes, and determine whether this is modified by sex, body mass index (BMI) and beverage type.

DESIGN

Multicentre prospective case-cohort study.

SETTING

Eight countries from the European Prospective Investigation into Cancer and Nutrition cohort.

SUBJECTS

A representative baseline sample of 16 154 participants and 12 403 incident cases of type 2 diabetes.

INTERVENTIONS

Alcohol consumption assessed using validated dietary questionnaires.

MAIN OUTCOME MEASURES

Occurrence of type 2 diabetes based on multiple sources (mainly self-reports), verified against medical information.

RESULTS

Amongst men, moderate alcohol consumption was nonsignificantly associated with a lower incidence of diabetes with a hazard ratio (HR) of 0.90 (95% CI: 0.78-1.05) for 6.1-12.0 versus 0.1-6.0 g day(-1) , adjusted for dietary and diabetes risk factors. However, the lowest risk was observed at higher intakes of 24.1-96.0 g day(-1) with an HR of 0.86 (95% CI: 0.75-0.98). Amongst women, moderate alcohol consumption was associated with a lower incidence of diabetes with a hazard ratio of 0.82 (95% CI: 0.72-0.92) for 6.1-12.0 g day(-1) (P interaction gender <0.01). The inverse association between alcohol consumption and diabetes was more pronounced amongst overweight (BMI ≥ 25 kg m(-2) ) than normal-weight men and women (P interaction < 0.05). Adjusting for waist and hip circumference did not alter the results for men, but attenuated the association for women (HR=0.90, 95% CI: 0.79-1.03 for 6.1-12.0 g day(-1) ). Wine consumption for men and fortified wine consumption for women were most strongly associated with a reduced risk of diabetes.

CONCLUSIONS

The results of this study show that moderate alcohol consumption is associated with a lower risk of type 2 diabetes amongst women only. However, this risk reduction is in part explained by fat distribution. The relation between alcohol consumption and type 2 diabetes was stronger for overweight than normal-weight women and men.

A combination of HbA1c, fasting glucose and BMI is effective in screening for individuals at risk of future type 2 diabetes: OGTT is not needed

OBJECTIVE

To identify a screening model that predicts high risk of future type 2 diabetes and is useful in clinical practice.

DESIGN AND METHODS

Incident case-referent study nested within a population-based health survey. We compared screening models with three risk criteria and calculated sensitivity, specificity, positive (PPV) and negative (NPV) predictive values and attributable proportion. We used fasting plasma glucose (FPG) alone or with an oral glucose tolerance test (OGTT), glycosylated haemoglobin A (HbA1c) (normal range 3.6-5.3%), body mass index (BMI), triglycerides and family history of diabetes (FHD).

SETTING

Participants in a health survey at all primary care centres (n=33,336) and subjects with diagnosed type 2 diabetes in primary and hospital care (n=6088) in Umeå during 1989-2001.

SUBJECTS

Each of the 164 subjects who developed clinically diagnosed type 2 diabetes (median time to diagnosis of 5.4 years) and 304 sex- and age-matched referents without diabetes diagnosis.

RESULTS

Screening models with at least one criterion present had sensitivities of 0.90-0.96, specificities of 0.43-0.57 and PPVs of 8-9%. Combinations of the criteria, FPG>or=6.1 mmol L-1 (capillary plasma), HbA1c>or=4.7% and BMI>or=27 in men and BMI>or=30 in women, had sensitivities, specificities and PPVs of 0.66%, 0.93% and 32%, and 0.52%, 0.97% and 46% respectively. Using FHD as one of three risk criteria showed comparable results. Addition of triglycerides or OGTT did not improve the prediction.

CONCLUSIONS

The combination of HbA1c, FPG and BMI are effective in screening for individuals at risk of future clinical diagnosis of type 2 diabetes. OGTT or FHD is not necessary.

Diabetes and onset of natural menopause: results from the European Prospective Investigation into Cancer and Nutrition

STUDY QUESTION

Do women who have diabetes before menopause have their menopause at an earlier age compared with women without diabetes?

SUMMARY ANSWER

Although there was no overall association between diabetes and age at menopause, our study suggests that early-onset diabetes may accelerate menopause.

WHAT IS KNOWN ALREADY

Today, more women of childbearing age are being diagnosed with diabetes, but little is known about the impact of diabetes on reproductive health.

STUDY DESIGN, SIZE, DURATION

We investigated the impact of diabetes on age at natural menopause (ANM) in 258 898 women from the European Prospective Investigation into Cancer and Nutrition (EPIC), enrolled between 1992 and 2000.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Determinant and outcome information was obtained through questionnaires. Time-dependent Cox regression analyses were used to estimate the associations of diabetes and age at diabetes diagnosis with ANM, stratified by center and adjusted for age, smoking, reproductive and diabetes risk factors and with age from birth to menopause or censoring as the underlying time scale.

MAIN RESULTS AND THE ROLE OF CHANCE

Overall, no association between diabetes and ANM was found (hazard ratio (HR) = 0.94; 95% confidence interval (CI) 0.89-1.01). However, women with diabetes before the age of 20 years had an earlier menopause (10-20 years: HR = 1.43; 95% CI 1.02-2.01, <10 years: HR = 1.59; 95% CI 1.03-2.43) compared with non-diabetic women, whereas women with diabetes at age 50 years and older had a later menopause (HR = 0.81; 95% CI 0.70-0.95). None of the other age groups were associated with ANM.

LIMITATIONS, REASONS FOR CAUTION

Strengths of the study include the large sample size and the broad set of potential confounders measured. However, results may have been underestimated due to survival bias. We cannot be sure about the sequence of the events in women with a late age at diabetes, as both events then occur in a short period. We could not distinguish between type 1 and type 2 diabetes.

WIDER IMPLICATIONS OF THE FINDINGS

Based on the literature, an accelerating effect of early-onset diabetes on ANM might be plausible. A delaying effect of late-onset diabetes on ANM has not been reported before, and is not in agreement with recent studies suggesting the opposite association.

STUDY FUNDING/COMPETING INTERESTS

The coordination of EPIC is financially supported by the European Commission (DG-SANCO) and the International Agency for Research on Cancer. The national cohorts are supported by Danish Cancer Society (Denmark); Ligue Contre le Cancer, Institut Gustave Roussy, Mutuelle Générale de l'Education Nationale, Institut National de la Santé et de la Recherche Médicale (INSERM) (France); German Cancer Aid, German Cancer Research Center (DKFZ) and Federal Ministry of Education and Research (BMMF) (Germany); Ministry of Health and Social Solidarity, Stavros Niarchos Foundation and Hellenic Health Foundation (Greece); Italian Association for Research on Cancer (AIRC) and National Research Council (Italy); Dutch Ministry of Public Health, Welfare and Sports (VWS), Netherlands Cancer Registry (NKR), LK Research Funds, Dutch Prevention Funds, Dutch ZON (Zorg Onderzoek Nederland), World Cancer Research Fund (WCRF), Statistics Netherlands (The Netherlands); ERC-2009-AdG 232997 and Nordforsk, Nordic Centre of Excellence programme on Food, Nutrition and Health (Norway); Health Research Fund (FIS), Regional Governments of Andalucía, Asturias, Basque Country, Murcia (no. 6236) and Navarra, ISCIII RETIC (RD06/0020) (Spain); Swedish Cancer Society, Swedish Scientific Council and Regional Government of Skåne and Västerbotten (Sweden); Cancer Research UK, Medical Research Council, Stroke Association, British Heart Foundation, Department of Health, Food Standards Agency, and Wellcome Trust (UK). None of the authors reported a conflict of interest.

Glutamate decarboxylase (GAD65) and tyrosine phosphatase-like protein (IA-2) autoantibodies index in a regional population is related to glucose intolerance and body mass index

AIMS/HYPOTHESIS

Our aims were to investigate the concentrations and prevalence of autoantibodies against the Mr 65.000 isoform of glutamate decarboxylase (GAD65) and the tyrosine phosphatase-like protein (IA-2) in adults and to test the hypothesis that GAD65 and IA-2 autoantibodies in a regional population are related to abnormal oral glucose tolerance.

METHODS

We analysed serum from 2157 Swedish subjects aged either 30, 40, 50 or 60 years old who, in 1988-1992, participated in the Västerbotten County Health Project and were subjected to the World Health Organisation (WHO) standard oral glucose tolerance test at entry into the study.

RESULTS

We found 23 of 2157 (1.1%) and 17 of 2152 (0.8%) subjects exceeded the 99th centile of GAD65 autoantibody index and IA-2 autoantibody index, respectively. In 18 subjects with diabetic oral glucose tolerance test, GAD65 autoantibody concentrations were higher than in those with normal oral glucose tolerance test (p = 0.02). Subjects with IGT (n = 185) [corrected] and diabetes (n = 18), i.e. abnormal OGTT (n = 203) [corrected], had higher GAD65Ab [corrected] index compared with those with normal OGTT (p = 0.026) [corrected]. A stepwise multiple logistic regression test showed that the odds ratios for subjects in the highest BMI group to exceed the 95th or 99th GAD65 autoantibody centile were 3.6 (CI 1.4-8.9) and 17.6 (CI 2.6-121.6), respectively.

CONCLUSION/INTERPRETATION

GAD65 and IA-2 autoantibodies, are associated with impaired or diabetic glucose tolerance in an adult regional population. This observation together with the association between GAD65 autoantibody concentrations and body mass index indicate a possible relation between islet autoimmunity and beta-cell function abnormalities with obesity and insulin resistance.

Evaluating the discriminative power of multi-trait genetic risk scores for type 2 diabetes in a northern Swedish population

AIMS/HYPOTHESIS

We determined whether single nucleotide polymorphisms (SNPs) previously associated with diabetogenic traits improve the discriminative power of a type 2 diabetes genetic risk score.

METHODS

Participants (n = 2,751) were genotyped for 73 SNPs previously associated with type 2 diabetes, fasting glucose/insulin concentrations, obesity or lipid levels, from which five genetic risk scores (one for each of the four traits and one combining all SNPs) were computed. Type 2 diabetes patients and non-diabetic controls (n = 1,327/1,424) were identified using medical records in addition to an independent oral glucose tolerance test.

RESULTS

Model 1, including only SNPs associated with type 2 diabetes, had a discriminative power of 0.591 (p < 1.00 x 10(-20) vs null model) as estimated by the area under the receiver operator characteristic curve (ROC AUC). Model 2, including only fasting glucose/insulin SNPs, had a significantly higher discriminative power than the null model (ROC AUC 0.543; p = 9.38 x 10(-6) vs null model), but lower discriminative power than model 1 (p = 5.92 x 10(-5)). Model 3, with only lipid-associated SNPs, had significantly higher discriminative power than the null model (ROC AUC 0.565; p = 1.44 x 10(-9)) and was not statistically different from model 1 (p = 0.083). The ROC AUC of model 4, which included only obesity SNPs, was 0.557 (p = 2.30 x 10(-7) vs null model) and smaller than model 1 (p = 0.025). Finally, the model including all SNPs yielded a significant improvement in discriminative power compared with the null model (p < 1.0 x 10(-20)) and model 1 (p = 1.32 x 10(-5)); its ROC AUC was 0.626.

CONCLUSIONS/INTERPRETATION

Adding SNPs previously associated with fasting glucose, insulin, lipids or obesity to a genetic risk score for type 2 diabetes significantly increases the power to discriminate between people with and without clinically manifest type 2 diabetes compared with a model including only conventional type 2 diabetes loci.

Food intake of individuals with and without diabetes across different countries and ethnic groups

BACKGROUND/OBJECTIVES

Given the importance of nutrition therapy in diabetes management, we hypothesized that food intake differs between individuals with and without diabetes. We investigated this hypothesis in two large prospective studies including different countries and ethnic groups.

SUBJECTS/METHODS

Study populations were the European Prospective Investigation into Cancer and Nutrition Study (EPIC) and the Multiethnic Cohort Study (MEC). Dietary intake was assessed by food frequency questionnaires, and calibrated using 24h-recall information for the EPIC Study. Only confirmed self-reports of diabetes at cohort entry were included: 6192 diabetes patients in EPIC and 13 776 in the MEC. For the cross-sectional comparison of food intake and lifestyle variables at baseline, individuals with and without diabetes were matched 1:1 on sex, age in 5-year categories, body mass index in 2.5 kg/m(2) categories and country.

RESULTS

Higher intake of soft drinks (by 13 and 44% in the EPIC and MEC), and lower consumption of sweets, juice, wine and beer (>10% difference) were observed in participants with diabetes compared with those without. Consumption of vegetables, fish and meat was slightly higher in individuals with diabetes in both studies, but the differences were <10%. Findings were more consistent across different ethnic groups than countries, but generally showed largely similar patterns.

CONCLUSIONS

Although diabetes patients are expected to undergo nutritional education, we found only small differences in dietary behavior in comparison with cohort members without diabetes. These findings suggest that emphasis on education is needed to improve the current behaviors to assist in the prevention of complications.

Heat shock protein 27 is associated with better nerve function and fewer signs of neuropathy

AIMS/HYPOTHESIS

High levels of serum heat shock protein 27 (sHSP27) have been associated with distal symmetric polyneuropathy in patients with type 1 diabetes. Our objective was to investigate the association between sHSP27, neuropathic signs and nerve function in individuals with normal glucose tolerance (NGT), impaired glucose tolerance (IGT) and type 2 diabetes.

METHODS

Participants were recruited consecutively from the population-based Västerbotten Intervention Program (NGT, n = 39, IGT, n = 29, and type 2 diabetes, n = 51) and were matched for age and sex. sHSP27 levels were measured and nerve conduction studies were performed (peroneal and sural nerves). z Scores for each nerve conduction measure were calculated and compiled into a composite z score for the leg. Neuropathy disability score (NDS) was used to assess neuropathic signs.

RESULTS

Patients with diabetes had significantly lower sHSP27 levels (geometric mean sHSP27 206 pg/ml, 95% CI 142, 299) than those with IGT (geometric mean sHSP27 455 pg/ml, 95% CI 319, 650, p < 0.05) and controls (geometric mean sHSP27 361 pg/ml, 95% CI 282, 461, p < 0.05). Participants with few signs of neuropathy (first tertile, NDS ≤2) had significantly higher sHSP27 levels (geometric mean sHSP27 401 pg/ml, 95% CI 310, 520) than participants with many signs (third tertile, NDS ≥7) (geometric mean sHSP27 192 pg/ml, 95% CI 128, 288, p = 0.007). The highest sHSP27 tertile was associated with better nerve function, adjusted for age, sex, statin medication and HbA(1c) (OR 2.51, 95% CI 1.25, 5.05, p < 0.05).

CONCLUSIONS/INTERPRETATION

High sHSP27 levels were associated with better nerve function and fewer neuropathic signs in NGT, IGT and type 2 diabetes.

Worse glycaemic control in LADA patients than in those with type 2 diabetes, despite a longer time on insulin therapy

AIMS/HYPOTHESIS

Our aim was to study whether glycaemic control differs between individuals with latent autoimmune diabetes in adults (LADA) and patients with type 2 diabetes, and whether it is influenced by time on insulin therapy.

METHODS

We performed a retrospective study of 372 patients with LADA (205 men and 167 women; median age 54 years, range 35-80 years) from Swedish cohorts from Skåne (n = 272) and Västerbotten (n = 100). Age- and sex-matched patients with type 2 diabetes were included as controls. Data on the use of oral hypoglycaemic agents (OHAs), insulin and insulin-OHA combination therapy was retrieved from the medical records. Poor glycaemic control was defined as HbA(1c) ≥7.0% (≥53 mmol/mol) at follow-up.

RESULTS

The individuals with LADA and with type 2 diabetes were followed for an average of 107 months. LADA patients were leaner than type 2 diabetes patients at diagnosis (BMI 27.7 vs 31.0 kg/m(2); p < 0.001) and follow-up (BMI 27.9 vs 30.2 kg/m(2); p < 0.001). Patients with LADA had been treated with insulin for longer than those with type 2 diabetes (53.3 vs 28.8 months; p < 0.001). There was no significant difference between the patient groups with regard to poor glycaemic control at diagnosis, but more patients with LADA (67.8%) than type 2 diabetes patients (53.0%; p < 0.001) had poor glycaemic control at follow-up. Patients with LADA had worse glycaemic control at follow-up compared with participants with type 2 diabetes (OR = 1.8, 95% CI 1.2, 2.7), adjusted for age at diagnosis, HbA(1c), BMI at diagnosis, follow-up time and duration of insulin treatment.

CONCLUSIONS/INTERPRETATION

Individuals with LADA have worse glycaemic control than patients with type 2 diabetes despite a longer time on insulin therapy.

Healthy behaviours and 10-year incidence of diabetes: a population cohort study

OBJECTIVE

To examine the association between meeting behavioural goals and diabetes incidence over 10 years in a large, representative Swedish population.

METHODS

Population-based prospective cohort study of 32,120 individuals aged 35 to 55 years participating in a health promotion intervention in Västerbotten County, Sweden (1990 to 2013). Participants underwent an oral glucose tolerance test, clinical measures, and completed diet and activity questionnaires. Poisson regression quantified the association between achieving six behavioural goals at baseline - body mass index (BMI) <25 kg/m(2), moderate physical activity, non-smoker, fat intake <30% of energy, fibre intake ≥15 g/4184 kJ and alcohol intake ≤20 g/day - and diabetes incidence over 10 years.

RESULTS

Median interquartile range (IQR) follow-up time was 9.9 (0.3) years; 2211 individuals (7%) developed diabetes. Only 4.4% of participants met all 6 goals (n=1245) and compared to these individuals, participants meeting 0/1 goals had a 3.74 times higher diabetes incidence (95% confidence interval (CI)=2.50 to 5.59), adjusting for sex, age, calendar period, education, family history of diabetes, history of myocardial infarction and long-term illness. If everyone achieved at least four behavioural goals, 14.1% (95% CI: 11.7 to 16.5%) of incident diabetes cases might be avoided.

CONCLUSION

Interventions promoting the achievement of behavioural goals in the general population could significantly reduce diabetes incidence.

Prediction of diabetes with body mass index, oral glucose tolerance test and islet cell autoantibodies in a regional population

OBJECTIVE

Our aim was to test the hypothesis that a combination of markers for Type 1 diabetes (glutamate decarboxylase and IA-2 autoantibodies) and for Type 2 diabetes [oral glucose tolerance test (OGTT) and body mass index (BMI)], would predict clinical diabetes in a regional population.

DESIGN

A population-based follow-up cohort study.

SETTING

Participants visited the primary health care centre in Lycksele, Sweden in 1988-92.

PARTICIPANTS

A cohort of 2278 subjects (M/F 1149/1129) who were studied at follow-up in 1998. At base line there were 2314 subjects (M/F 1167/1147) who participated in the Västerbotten Intervention Program on their birthday when turning either 30, 40, 50 or 60 years of age. Main outcome measurements. A clinically diagnosed diabetes at follow-up when the medical records were reviewed for diagnosis of diabetes. At base line, the participants were subjected to a standard OGTT and their BMI determined along with the autoantibodies.

RESULTS

At follow-up, 42/2278 (1.8%, 95% CI 1.2-2.3) (M/F 23/19) had developed diabetes: 41 subjects were clinically classified with Type 2 and one with Type 1 diabetes. There was no significant relation between autoantibody levels at base line and diabetes at follow-up. Stepwise multiple logistic regression showed that the odds ratio for developing diabetes was 10.8 (95% CI 6.3-18.9) in subjects in the fourth quartile of BMI (BMI > 27) compared with 7.8 (95% CI 4.8-12.6) in the fourth quartile of 2-h plasma glucose (>7.5 mmol L(-1)) and 7.2 (95% CI 4.8-11.4) in the fourth quartile of the fasting plasma glucose (>5.6 mmol L(-1)).

CONCLUSION

Islet cell autoantibodies did not predict diabetes at follow-up. BMI measured at base line was as effective as 2-h plasma glucose and fasting plasma glucose to predict diabetes in this adult population.

Higher leptin levels in Asian Indians than Creoles and Europids: a potential explanation for increased metabolic risk

BACKGROUND AND PURPOSE

Leptin predicts cardiovascular diseases and type 2 diabetes, diseases to which Asian Indians are highly susceptible. As a risk marker, leptin's intra-individual and seasonal stability is unstudied and only small studies have compared leptin levels in Asian Indians with other populations. The aim of this study was to explore ethnicity related differences in leptin levels and its intra-individual and seasonal stability.

METHODS

Leptin and anthropometric data from the northern Sweden MONICA (3513 Europids) and the Mauritius Non-communicable Disease (2480 Asian Indians and Creoles) studies were used. In both studies men and women, 25- to 74-year old, participated in both an initial population survey and a follow-up after 5-13 years. For the analysis of seasonal leptin variation, a subset of 1780 participants, 30- to 60-year old, in the Västerbotten Intervention Project was used.

RESULTS

Asian Indian men and women had higher levels of leptin, leptin per body mass index (BMI) unit (leptin/BMI) or per cm in waist circumference (WC; leptin/waist) than Creoles and Europids when adjusted for BMI (all P<0.0005) or WC (all P<0.005). In men, Creoles had higher leptin, leptin/BMI and leptin/waist than Europids when adjusted for BMI or WC (all P<0.0005). In women, Creoles had higher leptin/BMI and leptin/waist than Europids only when adjusted for WC (P<0.0005). Asian Indian ethnicity in both sexes, and Creole ethnicity in men, was independently associated with high leptin levels. The intra-class correlation for leptin was similar (0.6-0.7), independently of sex, ethnicity or follow-up time. No seasonal variation in leptin levels was seen.

CONCLUSION

Asian Indians have higher levels of leptin, leptin/BMI and leptin/waist than Creoles and Europids. Leptin has a high intra-individual stability and seasonal leptin variation does not appear to explain the ethnic differences observed here.

Consumption of fatty foods and incident type 2 diabetes in populations from eight European countries

BACKGROUND/OBJECTIVES

Diets high in saturated and trans fat and low in unsaturated fat may increase type 2 diabetes (T2D) risk, but studies on foods high in fat per unit weight are sparse. We assessed whether the intake of vegetable oil, butter, margarine, nuts and seeds and cakes and cookies is related to incident T2D.

SUBJECTS/METHODS

A case-cohort study was conducted, nested within eight countries of the European Prospective Investigation into Cancer (EPIC), with 12,403 incident T2D cases and a subcohort of 16,835 people, identified from a cohort of 340,234 people. Diet was assessed at baseline (1991-1999) by country-specific questionnaires. Country-specific hazard ratios (HRs) across four categories of fatty foods (nonconsumers and tertiles among consumers) were combined with random-effects meta-analysis.

RESULTS

After adjustment not including body mass index (BMI), nonconsumers of butter, nuts and seeds and cakes and cookies were at higher T2D risk compared with the middle tertile of consumption. Among consumers, cakes and cookies were inversely related to T2D (HRs across increasing tertiles 1.14, 1.00 and 0.92, respectively; P-trend <0.0001). All these associations attenuated upon adjustment for BMI, except the higher risk of nonconsumers of cakes and cookies (HR 1.57). Higher consumption of margarine became positively associated after BMI adjustment (HRs across increasing consumption tertiles: 0.93, 1.00 and 1.12; P-trend 0.03). Within consumers, vegetable oil, butter and nuts and seeds were unrelated to T2D.

CONCLUSIONS

Fatty foods were generally not associated with T2D, apart from weak positive association for margarine. The higher risk among nonconsumers of cakes and cookies needs further explanation.

Recognition of glutamic acid decarboxylase (GAD) by autoantibodies from different GAD antibody-positive phenotypes

Autoantibodies against the smaller isoform of glutamic acid decarboxylase (GAD) are markers for Type 1 diabetes. GAD65 autoantibody (GAD65Ab)-positive individuals in the general population are, however, mostly at low risk of developing Type 1 diabetes, suggesting that GAD65Ab phenotypes may be associated with different underlying pathogenic processes. The aim of this study was to test the hypothesis that Type 1 diabetes patients (n = 243; group I), GAD65Ab-positive healthy individuals (n = 28; group II), and healthy first-degree relatives of Type 1 diabetes patients (n = 41; group III) have antibody phenotypes that recognize different GAD65 epitopes. Sera from groups I-III were tested for their binding to GAD65 and GAD67, as well as six different GAD65/67 fusion proteins. Regardless of group, sera reactive to both GAD65 and GAD67 showed broader epitope reactivity than GAD65-specific sera. Furthermore, Type 1 diabetes patients showed a more restricted epitope binding than healthy individuals and first-degree relatives, demonstrating significantly less binding to the N-terminal part of GAD65 and to GAD67. Our analysis demonstrates that the N-terminal part is essential for full antibody binding to GAD65, in particular, to the middle epitope. It is suggested that Type 1 diabetes is associated with restricted GAD65Ab epitope specificity.

Longitudinal changes in epitope recognition of autoantibodies against glutamate decarboxylase 65 (GAD65Ab) in prediabetic adults developing diabetes

We analysed the beta cell-specific autoimmunity reflected in autoantibodies to the smaller isoform of glutamate decarboxylase (GAD65Ab) in the prediabetic period of GAD65Ab-positive healthy adults who developed Type 2 diabetes (T2D) during a follow-up period of 10 years. We found that of the adults that tested GAD65Ab-positive at baseline (n=25), six developed T2D and one developed Type 1 diabetes (T1D). Of the subjects that tested GAD65Ab-negative at baseline (n=2209), 81 developed T2D, one developed T1D and four developed unclassified diabetes, indicating that the risk for GAD65Ab-positive healthy adults to develop diabetes is increased sixfold. The GAD65Ab epitopes were characterized in a competition radioligand binding assay using recombinant Fab derived of GAD65-specific monoclonal antibodies. We observed that the GAD65Ab epitope specificities in the prediabetic period changed dynamically. Specifically, the binding to a middle and a C-terminal epitope increased during the follow-up period (P=0 x 03), causing a significant increase in the number of epitopes recognized (P=0 x 03). These findings are similar to previous observations of dynamic changes in the prediabetic period of schoolchildren at high risk for T1D development. However, the character of the epitopes differs between the two populations, suggesting differences in the beta cell-specific autoimmune response in the prediabetic period of patients with latent autoimmune diabetes in adults (LADA) and T1D.