BMI is an important driver of beta-cell loss in type 1 diabetes upon diagnosis in 10 to 18-year-old children.

OBJECTIVE: Body weight-related insulin resistance probably plays a role in progression to type 1 diabetes, but has an uncertain impact following diagnosis. In this study, we investigated whether BMI measured at diagnosis was an independent predictor of C-peptide decline 1-year post-diagnosis. DESIGN: Multicentre longitudinal study carried out at diagnosis and up to 1-year follow-up. METHODS: Data on C-peptide were collected from seven diabetes centres in Europe. Patients were grouped according to age at diagnosis (5 years 10 years 18 years, n=410). Linear regression was used to investigate whether BMI was an independent predictor of change in fasting C-peptide over 1 year. Models were additionally adjusted for baseline insulin dose and HbA1c. RESULTS: In individuals diagnosed between 0 and 5 years, 5 and 10 years and those diagnosed >18 years, we found no association between BMI and C-peptide decline. In patients aged 10-18 years, higher BMI at baseline was associated with a greater decline in fasting C-peptide over 1 year with a decrease (beta 95% CI; P value) of 0.025 (0.010, 0.041) nM/kg per m(2) higher baseline BMI (P=0.001). This association remained significant after adjusting for gender and differences in HbA1c and insulin dose (beta=0.026, 95% CI=0.0097, 0.042; P=0.002). CONCLUSIONS: These observations indicate that increased body weight and increased insulin demand are associated with more rapid disease progression after diagnosis of type 1 diabetes in an age group 10-18 years. This should be considered in studies of beta-cell function in type 1 diabetes

"I am pregnant and my husband has diabetes. Is there a risk for my child?" A qualitative study of questions asked by email about the role of genetic susceptibility to diabetes

<p>Abstract</p> <p>Background</p> <p>Diabetes Mellitus is a global health problem. Scientific knowledge on the genetics of diabetes is expanding and is more and more utilised in clinical practice and primary prevention strategies. Health consumers have become increasingly interested in genetic information. In the Netherlands, the <it>National Genetic Research and Information Center </it>provides online information about the genetics of diabetes and thereby offers website visitors the opportunity to ask a question per email. The current study aims at exploring people's need of (additional) information about the role of inheritance in diabetes. Results may help to tailor existing clinical and public (online) genetic information to the needs of an increasing population at risk for diabetes.</p> <p>Methods</p> <p>A data base with emailed questions about diabetes and inheritance (n = 172) is used in a secondary content analysis. Questions are posted in 2005-2009 via a website providing information about more than 600 inheritable disorders, including all diabetes subtypes. Queries submitted were classified by contents as well as persons' demographic profiles.</p> <p>Results</p> <p>Questions were received by diabetes patients (49%), relatives (30%), and partners (21%). Questioners were relatively young (54.8% ≤ 30 years) and predominantly female (83%). Most queries related to type 1 diabetes and concerned topics related to (future) pregnancy and family planning. Questioners mainly asked for risk estimation, but also clarifying information (about genetics of diabetes in general) and advice (mostly related to family planning) was requested. Preventive advice to reduce own diabetes risk was hardly sought.</p> <p>Conclusions</p> <p>Genetic information on diabetes provided by professionals or public health initiatives should address patients, as well as relatives and partners. In particular women are receptive to genetic information; they worry about the diabetes related health of (future) offspring. It seems important that information on the contribution of genetics to type 1 diabetes is more readily available. Considering the high prevalence of type 2 diabetes with strong evidence for a genetic predisposition, more effort seems needed to promote awareness around familial clustering and primary prevention.</p

Association of hypoxia inducible factor-1 alpha gene polymorphism with both type 1 and type 2 diabetes in a Caucasian (Hungarian) sample

BACKGROUND: Hypoxia inducible factor-1 alpha (HIF-1alpha) is a transcription factor that plays an important role in neo-vascularisation, embryonic pancreas beta-cell mass development, and beta cell protection. Recently a non synonymous single nucleotide polymorphism (g.C45035T SNP, rs11549465) of HIF-1alpha gene, resulting in the p.P582S amino acid change has been shown to be associated with type 2 diabetes (T2DM) in a Japanese population. Our aim was to replicate these findings on a Caucasian (Hungarian) population, as well as to study whether this genetic effect is restricted to T2DM or can be expanded to diabetes in general. METHODS: A large Caucasian sample (N = 890) was recruited including 370 T2DM, 166 T1DM and 354 healthy subjects. Genotyping was validated by two independent methods: a restriction fragment analysis (RFLP) and a real time PCR using TaqMan probes. An overestimation of heterozygotes by RFLP was observed as a consequence of a nearby SNP (rs34005929). Therefore genotyping results of the justified TaqMan system were accepted. The measured genotype distribution corresponded to Hardy-Weinberg equilibrium (P = 0.740) RESULTS: As the TT genotype was extremely rare in the population (0.6% in clinical sample and 2.5% in controls), the genotypes were grouped as T absent (CC) and T present (CT and TT). Genotype-wise analysis showed a significant increase of T present group in controls (24.0%) as compared to patients (16.8%, P = 0.008). This genetic effect was demonstrated in the separated samples of type 1 (15.1%, P = 0.020), and also in type 2 (17.6%, P = 0.032) diabetes. Allele-wise analysis gave identical results showing a higher frequency of the T allele in the control sample (13.3%) than in the clinical sample (8.7%, P = 0.002) with similar results in type 1 (7.8%, P = 0.010) and type 2 (9.1%, P = 0.011) diabetes. The odds ratio for diabetes (either type 1 or 2) was 1.56 in the presence of the C allele. CONCLUSION: We confirmed the protective effect of a rare genetic variant of HIF-1alpha gene against type 2 diabetes in a Caucasian sample. Moreover we demonstrated a genetic contribution of the same polymorphism in type 1 diabetes as well, supporting a possible overlap in pathomechanism for T2DM and a T1DM

Quantitative analyses comparing all major spleen cell phenotypes in BB and normal rats: autoimmune imbalance and double negative T cells associated with resistant, prone and diabetic animals.

The BB rat is a model of spontaneous autoimmune diabetes. To characterize quantitatively all known immune cell subsets involved in disease pathogenesis, FACS analysis of spleen cells was performed in diabetes-prone (DP) and acutely diabetic (D) BB rats and compared with diabetes-resistant (DR) BB and normal Wistar-Furth (WF) strains. We observed increased percentages of splenic NK cells in DP and D animals compared with DR rats using an NK-specific monoclonal antibody. We found increased proportions of splenic macrophages in the T-lymphopenic DP and D rats and low macrophage contents in DR spleens compared with WF spleens. We observed that percentages of the CD4-CD8- T cell receptor alpha/beta+ (double-negative) T cell subset were strikingly increased in the lymphopenic DP and D animals, compared with DR animals. We observed increased percentages of activated splenic CD5+ T cells expressing the IL-2 receptor and MHC class II antigen in DP and D rats compared with DR animals. Our studies suggest that (a) splenic NK cells and macrophages quantitatively appear to be involved in the pathogenesis of diabetes; (b) double-negative T cells escape from the T cell depletion process; (c) a marked increase of activated splenic T cells suggests diabetes is associated with general T cell activation processes; and (d) an altered balance among the different immune cell subsets may in part explain the pathogenesis of diabetes, since marked relative changes are observed when comparing the DR strain to the DP strain in both the prediabetic and diabetic stages

Quantitative phenotypic and functional analyses of islet immune cells before and after diabetes onset in the BB rat.

Inflammatory cells invading islets are thought to be mediators of islet destruction in spontaneous autoimmune diabetes mellitus. Thus methods were developed to isolate and characterize in situ islet inflammatory cells from 75-95-day-old prediabetic and diabetic BB rats. Islet inflammatory cells were structurally examined using single- and double-colour flow cytometry. Functional studies consisted of cytolytic assays using normal rat islet target cells and in situ islet or spleen effector cells. Structural data reveal natural killer cells to be the major cell population (70%) of total immune cells present in inflamed islets during prediabetes. At diabetes onset, the natural killer cell population remained at a high level (47%), but an increasing population of T cells (40%) was noted also. Analyses of T-cell subsets before and after diabetes onset revealed CD4+ T cells as predominant (50-55% of total T cells) with double-negative (CD4-CD8-) T cells (25-30%) and CD8+ T cells (15-20%) also present in significant quantities. Activated T cells accounted only for a minority of T cells (&lt; 3%). Functional studies indicate that in situ islet-derived cytolytic effector cells are more potent killers (ten-fold) of normal islet target cells than are splenic effector cells. These data suggest that in situ islet inflammatory cells (a) can be quantitatively studied both structurally and functionally; (b) express structural phenotypes differing substantially from splenic mononuclear cell populations; (c) are considerably more cytolytic than splenic effectors; and (d) should prove informative in determining the most significant autoimmune functional events prior to and during islet beta-cell destruction

The type 2 diabetes-associated variant in TCF7L2 is associated with latent autoimmune diabetes in adult Europeans and the gene effect is modified by obesity: a meta-analysis and an individual study.

AIMS/HYPOTHESIS: The variants of transcription factor 7-like 2 (TCF7L2) gene have been proposed to be associated with latent autoimmune diabetes in adults (LADA). We sought to confirm the possible association in Europeans and to examine the interaction between one gene variant and clinical data. METHODS: The TCF7L2 rs7903146 C-to-T polymorphism was genotyped in 211 LADA, 1,297 type 2 diabetic, 545 type 1 diabetic and 1,497 control individuals from Hungary. A meta-analysis of our and previously published studies was performed to evaluate the size and the heterogeneity of the gene effect. RESULTS: The meta-analysis yielded a significant effect of TCF7L2 T allele (OR 1.28; p < 0.0001) on LADA risk without heterogeneity among Europeans. The T allele conferred equally strong susceptibility to LADA and type 2 diabetes. In the Hungarian dataset, the T allele was associated with LADA and type 2 diabetes, but not with type 1 diabetes. T allele carriers had significantly lower BMI than patients with the CC genotype in the LADA and type 2 diabetes groups (p = 0.0021 and p = 0.0013, respectively). In both diseases, the diabetes risk was significantly higher in the non-overweight than in the overweight BMI category (p = 0.0013 and p < 0.0001, respectively); susceptibility to LADA was increased by 2.84-fold in non-overweight individuals compared with overweight ones. CONCLUSIONS/INTERPRETATION: The meta-analysis demonstrates that TCF7L2 rs7903146 polymorphism is a population-independent susceptibility locus for LADA in Europeans. The effect size is similar for LADA and type 2 diabetes. The gene effect on diabetes risk may be modulated by BMI, such that the lower the BMI, the higher the gene effect