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OBJECTIVE--To examine bβ-cell function across a spectrum of glycemia among Asian Indians, a population experiencing type 2 diabetes development at young ages despite low BMI. RESEARCH DESIGN AND METHODS--One-thousand two-hundred sixty-four individuals without known diabetes in the Diabetes Community Lifestyle Improvement Program in Chennai, India, had a 75-g oral glucose tolerance test, with glucose and insulin measured at 0, 30, and 120 min. Type 2 diabetes, isolated impaired fasting glucose (iIFG), isolated impaired glucose tolerance (iIGT), combined impaired fasting glucose and impaired glucose tolerance, and normal glucose tolerance (NGT) were defined by American Diabetes Association guidelines. Measures included insulin resistance and sensitivity (homeostasis model assessment of insulin resistance [HOMA-IR], modified Matsuda Index, 1/fasting insulin) and bβ-cell function (oral disposition index = [Δinsulin0-30/Δ glucose0-30] x [1/fasting insulin]). RESULTS--Mean age was 44.2 years (SD, 9.3) and BMI 27.4 kg/m² (SD, 3.8); 341 individuals had NGT, 672 had iIFG, IGT, or IFG plus IGT, and 251 had diabetes. Patterns of insulin resistance or sensitivity were similar across glycemic categories. With mild dysglycemia, the absolute differences in age- and sex-adjusted oral disposition index (NGT vs. iIFG, 38%; NGT vs. iIGT, 32%) were greater than the differences in HOMA-IR (NGT vs. iIFG, 25%; NGT vs. iIGT, 23%; each, 0.0001). Compared with NGT and adjusted for age, sex, BMI, waist circumference, and family history, the odds of mild dysglycemia were more significant per SD of oral disposition index (iIFG: odds ratio [OR], 0.36; 95% CI, 0.23-0.55; iIGT: OR, 0.37; 95% CI, 0.24-0.56) than per SD of HOMA-IR (iIFG: OR, 1.69; 95% CI, 1.23-2.33; iIGT: OR, 1.53; 95% CI, 1.11-2.11). CONCLUSIONS--Asian Indians with mild dysglycemia have reduced bβ-cell function, regardless of age, adiposity, insulin sensitivity, or family history. Strategies in diabetes prevention should minimize loss of ββ-cell function. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the prevalence of, and risk factors for, diabetic neuropathy among Asian Indian type 2 diabetic subjects. Subjects were recruited from CURES, a population-based study conducted on a representative population of Chennai city in south India. Of the 1529 known diabetic [KD] subjects, 1382 participated in the study [response rate: 90.4%]; in addition, 354 newly detected diabetic [NDD] subjects were also randomly selected. Neuropathy was diagnosed if the vibratory perception threshold of the right great toe measured by biothesiometry (Biomedical Instrument Co., Newbury, Ohio, USA) was ≥25. Of the total of 1736 individuals, biothesiometry studies were performed in 1632 subjects (94.0% response rate). The overall prevalence of neuropathy was 11% [age-standardized-5.8%], while it was 12.2% [age-standardized-6.5%] and 10% [age-standardized-5.2%] in male and female subjects respectively. The prevalence of neuropathy was significantly higher among KD subjects compared to NDD subjects [12.1% vs 6.8%, p=0.006]. It was also higher among subjects with diabetic retinopathy [26.9% vs 16.9%, p=0.001] and proteinuria [9.6% vs 5.3%, p=0.019] compared to those without. There was a linear increase in the prevalence of neuropathy with increasing age among both genders [p<0.0001]. The odds ratio (OR) for neuropathy in subjects having duration of diabetes >15 years was 5.51 [95% confidence interval (CI): 3.04-10.01, p<0.0001]. Multivariate logistic regression analysis showed age [OR: 1.16, 95% CI: 1.13-1.19, p<0.001], height [OR: 1.04, 95% CI: 1.01 -1.07, p=0.016] and fasting plasma glucose [OR: 1.00, 95% CI: 1.00 -1.01, p=0.001] to be significantly associated with neuropathy. Duration of diabetes showed an association with neuropathy but significance was lost when age was introduced into the model. This is the first population-based data on prevalence of diabetic neuropathy from India, which has the largest number of diabetic patients in the world. [ABSTRACT FROM AUTHOR]