A case-control study of risk factors for coronary heart disease in urban Indian middle-aged males.

ABSTRACT

OBJECTIVE: There are few case-control studies on native Indians to explore the reasons for the growing prevalence of coronary heart disease (CHD) in Indians. The present study was undertaken to identify the conventional coronary risk factors in angiographically proven CHD cases by comparing their prevalence in age-and gender-matched healthy controls. METHODOLOGY: A hospital-based case-control study was performed on 197 middle-aged urban males (age 40-64 years) with angiographically proven CHD and 197 age (32 years) and gender-matched healthy controls in a tertiary cardiac care center of New Delhi. Prevalence of coronary risk factors with special emphasis on diet was determined by administration of a pre-tested questionnaire, physical examination, and biochemical estimation of blood lipids and glucose. Odds ratios (OR) and their 95% confidence intervals (CI) for the association of risk factors with CHD and their population attributable risks (PAR) were calculated. RESULTS: Logistic regression analysis showed that history of diabetes mellitus (OR 4.934, 95% CI 2.320-10.494), low education (OR 2.410, 95% CI 1.261-4.608), full cream milk consumption (OR 2.113 95% CI 1.176-3.798), and family history of premature cardiovascular disease (CVD) (OR 1.810, 95% CI 1.064-3.079) were independent risk factors for CHD. High HDL-C (OR 1.055 95% CI 1.025-1.086) and fruit intake (OR 1.473, 95% CI 1.020-2.128) emerged as anti-risk factors. 44.1% of PAR was attributable to low HDL-C (.3%), low education status (6.6%), history of diabetes mellitus (6.0%), family history of premature CVD (4.4%), low fruit consumption (4.3%), tobacco abuse (4.2%), full cream milk consumption (3.6%) or milk intake (3.4%), high fasting blood glucose (2.3%), and history of hypertension (2.07 percent;). CONCLUSIONS: Conventional risk factors are not enough to explain the high prevalence of CHD among native Indians. While efforts must go on to reduce the risk attributable to them, the role of emerging risk factors should be investigated.