Diabetes and Insulin Resistance
- A high prevalence of insulin resistance and related atherogenic risk factors play a crucial role in the twin epidemics of cardiovascular disease (CVD) and diabetes in South Asians.1-3
- Insulin resistance is a central feature of the metabolic syndrome (MS), culminating in diabetes, atherosclerotic vascular disease, and coronary artery disease (CAD) ─ a pathway potentially accelerated by urbanization and/or migration within the country.
- In insulin resistance, normal amounts of insulin is insufficient to produce desired metabolic effects on fat, muscle, and liver cells; leading to various metabolic consequences including high levels of insulin, blood glucose, triglycerides, and low levels of HDL-C. 4
- Several studies have demonstrated that insulin resistance is highly prevalent and occurs at an earlier age and at a lower body mass index (BMI) and waist circumference (WC) in Asian Indians than Europids.5-13
- South Asians are more insulin resistant than whites and is related to excess visceral fat and abdominal obesity which in turn may result from small superficial adipose tissue compartment.3, 9, 14, 15
- Healthy lean nondiabetic Indians were more insulin resistant compared to other ethnic groups despite the similarity in living environment. These findings may warrant preventive health-care strategies for diabetes and CAD to target Indians at an earlier stage compared to other ethnic groups.16
- Obesity-related insulin resistance is associated with changes in adipose tissue release of leptin, adiponectin, and nonesterified fatty acids (NEFAs). Asian Indians manifest excessive insulin resistance even in the absence of obesity.
- Plasma concentrations of the adipose tissue metabolites leptin and NEFAs are higher and that of adiponectin is lower in insulin-resistant Asian Indians compared with more insulin-sensitive Caucasians. These differences may contribute to the excessive prevalence of diabetes and CVD in nonobese Asian Indians.17
- Compared to Europid men of same age and BMI, Asian Indians have higher plasma NEFAs and leptin and lower plasma concentrations of adiponectin.17
- The prevalence of insulin resistance, (defined as the lower quartile of insulin sensitivity index), was approximately 2- to 3-fold higher in the Asian-Indians.18
1. McKeigue PM, Shah B, Marmot MG. Relation of central obesity and insulin resistance with high diabetes prevalence and cardiovascular risk in South Asians. Lancet. 1991;337(8738):382-386.
2. Knight TM, Smith Z, Whittles A, et al. Insulin resistance, diabetes, and risk markers for ischaemic heart disease in Asian men and non-Asian in Bradford. Br Heart J. 1992;67(5):343-350.
3. Gholap N, Davies M, Patel K, Sattar N, Khunti K. Type 2 diabetes and cardiovascular disease in South Asians. Prim Care Diabetes. Sep 23 2010.
4. Sniderman AD, Bhopal R, Prabhakaran D, Sarrafzadegan N, Tchernof A. Why might South Asians be so susceptible to central obesity and its atherogenic consequences? The adipose tissue overflow hypothesis. Int J Epidemiol. Feb 2007;36(1):220-225.
5. Bhardwaj S, Misra A, Khurana L, Gulati S, Shah P, Vikram NK. Childhood obesity in Asian Indians: a burgeoning cause of insulin resistance, diabetes and sub-clinical inflammation. Asia Pacific journal of clinical nutrition. 2008;17 Suppl 1:172-175.
6. Raji A, Seely EW, Arky RA, Simonson DC. Body fat distribution and insulin resistance in healthy Asian Indians and Caucasians. The Journal of clinical endocrinology and metabolism. 2001;86(11):5366-5371.
7. Banerji MA, Faridi N, Atluri R, Chaiken RL, Lebovitz HE. Body composition, visceral fat, leptin, and insulin resistance in Asian Indian men. The Journal of clinical endocrinology and metabolism. 1999;84(1):137-144.
8. Whincup PH, Gilg JA, Papacosta O, et al. Early evidence of ethnic differences in cardiovascular risk: cross sectional comparison of British South Asian and white children. Bmj. 2002;324(7338):635.
9. Yajnik C. S, Lubree HG, Rege SS, et al. Adiposity and hyperinsulinemia in Indians are present at birth. The Journal of clinical endocrinology and metabolism. Dec 2002;87(12):5575-5580.
10. Ehtisham S, Crabtree N, Clark P, Shaw N, Barrett T. Ethnic differences in insulin resistance and body composition in United Kingdom adolescents. The Journal of clinical endocrinology and metabolism. Jul 2005;90(7):3963-3969.
11. Kolsgaard M. L., Andersen LF, Tonstad S, Brunborg C, Wangensteen T, Joner G. Ethnic differences in metabolic syndrome among overweight and obese children and adolescents: the Oslo Adiposity Intervention Study. Acta Paediatr. Nov 2008;97(11):1557-1563.
12. Ramachandran A, Snehalatha C, Latha E, Satyavani K, Vijay V. Clustering of cardiovascular risk factors in urban Asian Indians. Diabetes Care. 1998;21(6):967-971.
13. Chandalia M, Abate N, Garg A, Stray-Gundersen J, Grundy SM. Relationship between generalized and upper body obesity to insulin resistance in Asian Indian men. The Journal of clinical endocrinology and metabolism. 1999;84(7):2329-2335.
14. Shelgikar KM, Hockaday TD, Yajnik CS. Central rather than generalized obesity is related to hyperglycaemia in Asian Indian subjects. Diabet Med. Oct 1991;8(8):712-717.
15. Yajnik CS. The lifecycle effects of nutrition and body size on adult adiposity, diabetes and cardiovascular disease. Obes Rev. 2002;3(3):217-224.
16. Liew C. F., Seah ES, Yeo KP, Lee KO, Wise SD. Lean, nondiabetic Asian Indians have decreased insulin sensitivity and insulin clearance, and raised leptin compared to Caucasians and Chinese subjects. Int J Obes Relat Metab Disord. Jul 2003;27(7):784-789.
17. Abate N, Chandalia M, Snell PG, Grundy SM. Adipose tissue metabolites and insulin resistance in nondiabetic Asian Indian men. The Journal of clinical endocrinology and metabolism. Jun 2004;89(6):2750-2755.
18. Petersen K. F., Dufour S, Feng J, et al. Increased prevalence of insulin resistance and nonalcoholic fatty liver disease in Asian-Indian men. Proceedings of the National Academy of Sciences of the United States of America. Nov 28 2006;103(48):18273-18277.