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Aims/hypothesis: We aimed to evaluate the relationship between childhood growth measures and risk of developing islet autoimmunity (IA) and type 1 diabetes in children with an affected first-degree relative and increased HLA-conferred risk. We hypothesised that being overweight or obese during childhood is associated with a greater risk of IA and type 1 diabetes. Methods: Participants in a randomised infant feeding trial (N = 2149) were measured at 12 month intervals for weight and length/height and followed for IA (at least one positive out of insulin autoantibodies, islet antigen-2 autoantibody, GAD autoantibody and zinc transporter 8 autoantibody) and development of type 1 diabetes from birth to 10–14 years. In this secondary analysis, Cox proportional hazard regression models were adjusted for birthweight and length z score, sex, HLA risk, maternal type 1 diabetes, mode of delivery and breastfeeding duration, and stratified by residence region (Australia, Canada, Northern Europe, Southern Europe, Central Europe and the USA). Longitudinal exposures were studied both by time-varying Cox proportional hazard regression and by joint modelling. Multiple testing was considered using family-wise error rate at 0.05. Results: In the Trial to Reduce IDDM in the Genetically at Risk (TRIGR) population, 305 (14.2%) developed IA and 172 (8%) developed type 1 diabetes. The proportions of children overweight (including obese) and obese only were 28% and 9% at 10 years, respectively. Annual growth measures were not associated with IA, but being overweight at 2–10 years of life was associated with a twofold increase in the development of type 1 diabetes (HR 2.39; 95% CI 1.46, 3.92; p < 0.001 in time-varying Cox regression), and similarly with joint modelling. Conclusions/interpretation: In children at genetic risk of type 1 diabetes, being overweight at 2–10 years of age is associated with increased risk of progression from multiple IA to type 1 diabetes and with development of type 1 diabetes, but not with development of IA. Future studies should assess the impact of weight management strategies on these outcomes. Trial registration: ClinicalTrials.gov NCT00179777 Graphical abstract: [Figure not available: see fulltext.]

Additional file 1.

Differences in breastfeeding, other milk feeding and complementary feeding patterns were evaluated in infants at increased genetic risk with and without maternal type 1 diabetes (T1D). The Trial to Reduce IDDM in the Genetically at Risk is an international nutritional primary prevention double-blinded randomized trial to test whether weaning to extensively hydrolyzed vs. intact cow's milk protein formula will decrease the development of T1D-associated autoantibodies and T1D. Infant diet was prospectively assessed at two visits and seven telephone interviews between birth and 8 months. Countries were grouped into seven regions: Australia, Canada, Northern Europe, Southern Europe, Central Europe I, Central Europe II and the United States. Newborn infants with a first-degree relative with T1D and increased human leukocyte antigen-conferred susceptibility to T1D were recruited. A lower proportion of infants born to mothers with than without T1D were breastfed until 6 months of age in all regions (range, 51% to 60% vs. 70% to 80%). Complementary feeding patterns differed more by region than by maternal T1D. In Northern Europe, a higher proportion of infants consumed vegetables and fruits daily compared with other regions. Consumption of meat was more frequent in all European regions, whereas cereal consumption was most frequent in Southern Europe, Canada and the United States. Maternal T1D status was associated with breastfeeding and other milk feeding patterns similarly across regions but was unrelated to the introduction of complementary foods. Infant feeding patterns differed significantly among regions and were largely inconsistent with current recommended guidelines.

Aims/hypothesis. Type I (insulin-dependent) diabetes mellitus is characterized by selective destruction of the insulin producing beta cells. Interleukin-1β (IL-1β) modulates the beta-cell function, protein synthesis, energy production and causes apoptosis. We have previously shown changes in the expression of 82 out of 1 815 protein spots detected by two dimensional gel electrophoresis in IL-1β exposed diabetes prone Bio Breeding (BB-DP) rat islets of Langerhans in vitro. The aim of this study was to identify the proteins in these 82 spots by mass spectrometry and compare these changes with those seen in IL-1β exposed Wistar Furth (WF) rat islets. Methods. The 82 protein spots, that changed expression after IL-1β exposure, were all re-identified on preparative gels of 200 000 neonatal WF rat islets, cut out and subjected to mass spectrometry for identification. Results. Forty-five different proteins were identified from 51 spots and grouped according to function: (i) energy transduction and redox potentials; (ii) glycolytic and Krebs cycle enzymes; (iii) protein, DNA and RNA synthesis, chaperoning and protein folding; (iv) signal transduction, regulation, differentiation and apoptosis; (v) cellular defence; and (vi) other functions. Comparison of IL-1β exposed BB-DP and WF islets showed common changes in 14 proteins and several proteins influencing similar pathways, suggesting that similar routes in the two strains lead to beta-cell destruction. Conclusion/interpretation. We demonstrate that proteome analysis is a powerful tool to identify proteins and pathways in BB-DP rat islets exposed to IL-1β.