Heart Attacks and the South Asian Paradox: Do We Need Lower Desirable Targets for Prevention?
R B Singh, MD; Brian Tomlinson, MD; Neil Thomas, PhD; Rakesh Sharma
An informative look into risk factors for Coronary Artery Disease (CAD) in the South Asian population.
There is an unanimous agreement that people of south Asia have a genetic susceptibility for Coronary artery disease (CAD) and are adapted to survive with a smaller body frame size and on low fat diets (15-20% en/day) and physically demanding occupations. Therefore risk factors guidelines suggested for developed countries are not appropriate for prevention of CAD among them. The prevalence of CAD in India varies between 7-14% in urbans and 3-5% in rural population depending upon affluence. The prevalence of diabetes varies between 6-8% in urban and 2-3% in rural adults. Hypertension is 25-30% in urban and 10-15% in rural subjects. Mean serum cholesterol varies between 180-200mg/dl in urban and 160-170mg/dl. Smoking is 40% in rural and 25-30% in urban subjects. Plasma insulin responses were 25% lower in Moradabad urban sample compared to south India immigrants to UK. The extent and burden of these risk factors and CAD have been confirmed by the Five City Study which showed higher prevalence in Trivandrum in south India and Bombay in West India followed by Moradabaf in north India, Nagpur in central India and Calcutta in east India. The results of this study support the consensus that south Asians should have lower desirable limits of serum cholesterol, body mass index, waist-hip ratio and other risk factors which would require to modify the existing guidelines of the International Task Force for Prevention of CAD (WHF). The force of lipid related risk factors and of higher BMI appears to be greater in people of south Asian origin due to presence of central obesity, insulin resistance, higher lipoprotein (a), higher angiotensin converting enzyme, decreased beta cell function and inutro-undernutrition. Since hypertriglyceridemia and low HDL-C appear to be more common in this group, therefore statin alone would not help significantly. Fibrates, niacin, gemfibrozil have to be used along with enormous amount of physical activity for prevention of CAD. (See table for guideline).
Modified from Indian Consensus Group, 27 J Nutr Environ Med, 1996
R B Singh, MD, Professor of Medicine, Subharti Medical College, Medical Hospital and Research Centre, Moradabad, India
Brian Tomlinson, MD, Professor of Medicine and Therapeutics, Prince of Wales Hospital, Hong Kong
Neil Thomas, PhD, Assistant Professor, Therapeutics, Prince of Wales Hospital, Hong Kong
Rakesh Sharma, Research Scientist, College of Physicians and Surgeons, New York, USA