CLUSTERING OF CARDIOVASCULAR RISK-FACTORS IN URBAN ASIAN INDIANS

OBJECTIVE - To study the prevalence of cardiovascular risk factors in native urban Asian Indians and to look for the occurrence of clusterin g of these factors. RESEARCH DESIGN AND METHODS - The study included 9 53 subjects (532 men and 421 women), aged greater than or equal to 40 years, selected from a population survey for diabetes, which was condu cted in 1994 in Madras, Tamil Nadu, India. Measurements of anthropomet ry, blood pressure, plasma lipid profile, glucose tolerance, plasma in sulin response, and electrocardiogram were made. Based on the normal r anges derived from the population study, abnormalities in anthropometr ic values, plasma lipids, and insulin values were determined. Age-adju sted prevalences of the abnormalities were calculated using data from a 1991 urban census in Madras. The expected prevalences of the abnorma lities in isolation and in combinations were calculated and compared w ith the corresponding observed figures. RESULTS - The prevalences of r isk factors were in the order of central adiposity > dyslipidemia > hy perinsulinemia (2-h) > glucose intolerance > obesity > hypertension. T he age-adjusted prevalence of coronary heart disease (CHD) was 3.9% (3 .5% in men and 4.5% in women, NS), and T wave inversion was seen in an additional 10.3%. Isolated prevalences of all factors, except hyperte nsion, were in lower frequency than expected. Combinations of each ris k factor with one or two more risk factors occurred more frequently (1 .3-4 times) than expected by chance. Impaired glucose tolerance and dy slipidemia showed association with hyperinsulinemia, whereas hypertens ion did not show such an association. CONCLUSIONS - Clustering of the cardiovascular risk factors or the components of insulin resistance sy ndrome occurs in the native Asian Indian population. This finding unde rscores the need for preventive aspects of metabolic disorders and CHD .