TY - JOUR T1 - Incidence and pathophysiology of diabetes in South Asian adults living in India and Pakistan compared with US blacks and whites JF - BMJ Open Diabetes Research & Care JO - BMJ Open Diab Res Care DO - 10.1136/bmjdrc-2020-001927 VL - 9 IS - 1 SP - e001927 AU - K M Venkat Narayan AU - Dimple Kondal AU - Natalie Daya AU - Unjali P Gujral AU - Deepa Mohan AU - Shivani A Patel AU - Roopa Shivashankar AU - Ranjit Mohan Anjana AU - Lisa R Staimez AU - Mohammed K Ali AU - Howard H Chang AU - Masood Kadir AU - Dorairaj Prabhakaran AU - Elizabeth Selvin AU - Viswanathan Mohan AU - Nikhil Tandon Y1 - 2021/03/01 UR - http://drc.bmj.com/content/9/1/e001927.abstract N2 - Introduction We compared diabetes incidence in South Asians aged ≥45 years in urban India (Chennai and Delhi) and Pakistan (Karachi), two low-income and middle-income countries undergoing rapid transition, with blacks and whites in the US, a high-income country.Research design and methods We computed age-specific, sex-specific and body mass index (BMI)-specific diabetes incidence from the prospective Center for Cardiometabolic Risk Reduction in South Asia Study (n=3136) and the Atherosclerosis Risk in Communities Study (blacks, n=3059; whites, n=9924). We assessed factors associated with incident diabetes using Cox proportional hazards regression.Results South Asians have lower BMI and waist circumference than blacks and whites (median BMI, kg/m2: 24.9 vs 28.2 vs 26.0; median waist circumference, cm 87.5 vs 96.0 vs 95.0). South Asians were less insulin resistant than blacks and whites (age-BMI-adjusted homeostatic model assessment of insulin resistance, µIU/mL/mmol/L: 2.30 vs 3.45 vs 2.59), and more insulin deficient than blacks but not whites (age-BMI-adjusted homeostasis model assessment of β-cell dysfunction, µIU/mL/mmol/L: 103.7 vs 140.6 vs 103.9). Age-standardized diabetes incidence (cases/1000 person-years (95% CI)) in South Asian men was similar to black men and 1.6 times higher (1.37 to 1.92) than white men (26.0 (22.2 to 29.8) vs 26.2 (22.7 to 29.7) vs 16.1 (14.8 to 17.4)). In South Asian women, incidence was slightly higher than black women and 3 times (2.61 to 3.66) the rate in white women (31.9 (27.5 to 36.2) vs 28.6 (25.7 to 31.6) vs 11.3 (10.2 to 12.3)). In normal weight (BMI <25 kg/m2), diabetes incidence adjusted for age was 2.9 times higher (2.09 to 4.28) in South Asian men, and 5.3 times (3.64 to 7.54) in South Asian women than in white women.Conclusions South Asian adults have lower BMI and are less insulin resistant than US blacks and whites, but have higher diabetes incidence than US whites, especially in subgroups without obesity. Factors other than insulin resistance (ie, insulin secretion) may play an important role in the natural history of diabetes in South Asians. ER -