Incidence of diabetes in South Asian young adults compared to Pima Indians

• Type of Material: Article
• Authors: Kabayam Venkat Narayan, Emory University; Dimple Kondal, Public Health Foundation of India; Sayuko Kobes, National Institute of Diabetes and Digestive and Kidney Diseases; Lisa Staimez, Emory University; Deepa Mohan, Madras Diabetes Research Foundation; Unjali Gujral, Emory University; Shivani Patel, Emory University; Ranjit Mohan Anjana, Madras Diabetes Research Foundation; Roopa Shivashankar, Public Health Foundation of India; Mohammed Ali, Emory University; Howard Chang, Emory University; Masood Kadir, Aga Khan University; Dorairaj Prabhakaran, Emory University; Natalie Daya, Johns Hopkins University; Elizabeth Selvin, Johns Hopkins University; Nikhil Tandon, All India Institute of Medical Sciences; Robert Hanson, National Institute of Diabetes and Digestive and Kidney Diseases; Viswanathan Mohan, Dr Mohan’s Diabetes Specialities Centre Gopalapuram
• Language: English
• Date: 2021-01-01
• Publisher: BMJ PUBLISHING GROUP
• Publication Version: Final Published Version
• Copyright Statement: © Author(s) (or their employer(s)) 2021
• License: Creative Commons Attribution-NonCommercial 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1136/bmjdrc-2020-001988
• Title of Journal or Parent Work: BMJ OPEN DIABETES RESEARCH & CARE
• Volume: 9
• Issue: 1
• Grant/Funding Information: The CARRS Study was funded in part by the National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Department of Health and Human Services, under Contract No. HHSN268200900026C and the United Health Group, Minneapolis, MN, USA. KMVN, MKA, UPG, and SAP were funded in part by the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health under Award Number P30DK111024. KMVN was funded in part for ‘Worksite Lifestyle Program for Reducing Diabetes and Cardiovascular Risk in India’ project funded by NHLBI, NIH Department of Health and Human Services under Award number R01HL125442. SAP was funded in part by Department of Health and Human Services, National Institutes of Health, NHLBI under Award Number 5U01HL138635-02. SAP, KMVN, MKA, NT, and DP were supported in part by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH), award number 5U01HL138635 under the Hypertension Outcomes for T4 Research within Lower Middle-Income Countries (Hy-TREC) program. RS was supported by a Wellcome Trust Capacity Strengthening Strategic Award Extension phase to the Public Health Foundation of India and a consortium of UK universities (WT084754/Z/08/A) and was supported by grant number 1 D43 HD065249 from the Fogarty International Center and the Eunice Kennedy Shriver National Institute of Child Health and Human Development at the National Institutes of Health. DK has been supported by Fogarty International Center for PH leader Course, National Institutes of Health under grant number (D43TW009135). The Pima Indian study was supported by the intramural research program of the National Institute of Diabetes and Digestive and Kidney Diseases.
• Keywords: Science & Technology; Life Sciences & Biomedicine; NORMAL-WEIGHT; IMPAIRED GLUCOSE-TOLERANCE; RACIAL/ETHNIC GROUPS; type 2; BETA-CELL FUNCTION; Endocrinology & Metabolism; US; insulin secretion; GENDER-DIFFERENCES; WHITE; OBESITY; PREVALENCE; INSULIN-RESISTANCE; epidemiology; diabetes mellitus; insulin resistance
• Research Categories: Health Sciences, Epidemiology; Health Sciences, Public Health; Sociology, Ethnic and Racial Studies

Abstract

Introduction South Asians (SA) and Pima Indians have high prevalence of diabetes but differ markedly in body size. We hypothesize that young SA will have higher diabetes incidence than Pima Indians at comparable body mass index (BMI) levels. Research design and methods We used prospective cohort data to estimate age-specific, sex, and BMI-specific diabetes incidence in SA aged 20-44 years living in India and Pakistan from the Center for Cardiometabolic Risk Reduction in South Asia Study (n=6676), and compared with Pima Indians, from Pima Indian Study (n=1852). Results At baseline, SA were considerably less obese than Pima Indians (BMI (kg/m 2): 24.4 vs 33.8; waist circumference (cm): 82.5 vs 107.0). Age-standardized diabetes incidence (cases/1000 person-years, 95% CI) was lower in SA than in Pima Indians (men: 14.2, 12.2-16.2 vs 37.3, 31.8-42.8; women: 14.8, 13.0-16.5 vs 46.1, 41.2-51.1). Risk of incident diabetes among 20-24-year-old Pima men and women was six times (relative risk (RR), 95% CI: 6.04, 3.30 to 12.0) and seven times (RR, 95% CI: 7.64, 3.73 to 18.2) higher as compared with SA men and women, respectively. In those with BMI <25 kg/m 2, however, the risk of diabetes was over five times in SA men than in Pima Indian men. Among those with BMI ≥30 kg/m 2, diabetes incidence in SA men was nearly as high as in Pima men. SA and Pima Indians had similar magnitude of association between age, sex, BMI, and insulin secretion with diabetes. The effect of family history was larger in SA, whereas that of insulin resistance was larger in Pima Indians Conclusions In the background of relatively low insulin resistance, higher diabetes incidence in SA is driven by poor insulin secretion in SA men. The findings call for research to improve insulin secretion in early natural history of diabetes.