Risk Factors among Asian Indians
- When people immigrate to other countries or migrate to urban areas within the country they become increasingly sedentary. Decreased physical activity and increased consumption of calories and saturated fat result in abdominal obesity, insulin resistance, and atherogenic high blood cholesterol. These acquired metabolic abnormalities appear to have a synergistic effect on the development of CAD (coronary artery disease) in genetically susceptible individuals.1-3
- The Asian Indian paradox – refers to the high prevalence of heart disease in the absence of high prevalence of traditional risk factors. This was first observed in the CADI study which found a 4-fold higher rate of CAD that was accompanied by a lower prevalence of traditional risk factors. (Figure 013)
- The prevalence of conventional risk factors in Asian Indians was similar to, or lower than whites with the exception of diabetes, which was present in 8% of Asian Indians, compared with 1% in whites. Among the subjects of the CADI study, only 3% smoked >10 cigarettes/day and 7% had obesity.
- A detailed study of the dietary habits of a subgroup of 153 Asian Indian physicians showed a consumption of 56% energy from carbohydrates, 32% from fat, and 8% from saturated fat.4
- Leisure-time physical activity averaged 136 minutes/week and correlated directly with HDL (high-density lipoprotein) level.5 The prevalence of risk factors among Asian Indians are substantially different than those reported for whites and different ethnic groups in the US.
- The first phase of the CADI Study involved highly educated and motivated physicians and their family members who may not be representative of most Asian Indians in the US. Therefore, 255 non-physicians were studied in the second phase. Unlike the physicians, they had not made maximum modification of lifestyle and had a higher prevalence of risk factors (Table 105A). Their lipid profile, especially the high triglycerides and high total cholesterol/HDL ratio, was highly proatherogenic.
|Table 105A. Differences in prevalence of risk factors between Asian Indian physicians and non physicians in the CADI Study2, 6|
|TC, total cholesterol;TG, triglyceride;Lp(a), lipoprotein(a)|
- Other studies are in general agreement with the CADI Study results.7 Again, vegetarians, compared to non- vegetarians, had similar levels of lipids.7 Several studies have reported high levels of homocysteine among Asian Indians in the US.8
- Asian Indians in the US have high prevalence of elevated lipoprotein(a), diabetes, and metabolic syndrome, consistent with reports from around the world.9-11
1. Enas EA. Why is there an epidemic of malignant CAD in young Indians? Asian J Clin Cardiol. 1998;1:43-59.
2. Enas EA, Jacob S. Coronary artery disease in Indians in the USA. In: Sethi K, ed. Coronary artery disease in Indians – A Global Perspective. Mumbai: Cardiological Society of India; 1998:32-43.
3. Enas EA, Dhawan J, Petkar S. Coronary artery disease in Asian Indians: lessons learnt and the role of lipoprotein(a). Indian heart journal. Jan-Feb 1997;49(1):25-34.
4. Enas EA. How to Beat the Heart Disease Epidemic among South Asians: A Prevention and Management Guide for Asian Indians and their Doctors. Downers Grove: Advanced Heart Lipid Clinic USA; 2010.
5. Yagalla MV, Hoerr SL, Song WO, Enas E, Garg A. Relationship of diet, abdominal obesity, and physical activity to plasma lipoprotein levels in Asian Indian physicians residing in the United States. J Am Diet Assoc. 1996;96(3):257-261.
6. Enas EA, Garg A, Davidson MA, Nair VM, Huet BA, Yusuf S. Coronary heart disease and its risk factors in first-generation immigrant Asian Indians to the United States of America. Indian heart journal. Jul-Aug 1996;48(4):343-353.
7. Chuang CZ, Subramaniam PN, LeGardeur BY, Lopez A. Risk factors for coronary artery disease and levels of lipoprotein(a) and fat-soluble antioxidant vitamins in Asian Indians of USA. Indian heart journal. 1998;50(3):285-291.
8. Chambers JC, Kooner JS. Homocysteine: a novel risk factor for coronary heart disease in UK Indian Asians. Heart (British Cardiac Society). 2001;86(2):121-122.
9. Anand SS, Enas EA, Pogue J, Haffner S, Pearson T, Yusuf S. Elevated lipoprotein(a) levels in South Asians in North America. Metabolism. Feb 1998;47(2):182-184.
10. Kanaya AM, Wassel CL, Mathur D, et al. Prevalence and correlates of diabetes in South asian indians in the United States: findings from the metabolic syndrome and atherosclerosis in South asians living in america study and the multi-ethnic study of atherosclerosis. Metabolic syndrome and related disorders. Apr 2010;8(2):157-164.
11. Palaniappan L P, Wong EC, Shin JJ, Fortmann SP, Lauderdale DS. Asian Americans have greater prevalence of metabolic syndrome despite lower body mass index. International journal of obesity (2005). Aug 3 2010.