Differences in conventional cardiovascular risk factors in two ethnic groups in India

Studies have been carried out at national and international levels to assess ethnic variations in the prevalence of cardiovascular diseases and their risk factors. However, ethnic variations in the contribution of various risk factors to complex diseases have been scarcely studied.

Our study examined such variations in two ethnic groups in India, namely, Meiteis of Manipur (northeast India) and Aggarwals of Delhi (north India).

Through random sampling, we selected 635 participants from the Meitei community and 181 Aggarwals from the Aggarwal Dharmarth Hospital, Delhi. Patients with coronary artery disease (CAD) and hypertension were identified based on their recent medical diagnostic history. Anthropometric parameters such as height, weight, waist and hip circumferences along with physiological parameters (blood pressures, both systolic and diastolic) and biochemical parameter (lipid profile) were measured for all study participants. Patient parameters were available from the medical reports recorded when patients were first diagnosed.

Among CAD individuals, the Aggarwals showed higher mean values of weight, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), triglyceride (TC), low density lipoprotein (LDL), and very low density lipoprotein (VLDL) but had lower high density lipoprotein (HDL) levels than the Meiteis. The same trend for weight, BMI and lipid parameters could be seen among hypertensive individuals. In step-wise regression analysis, SBP, LDL and TG were found to significantly contribute to the risk for CAD in the Aggarwals; whereas in the Meiteis, SBP, VLDL, HDL, TC and LDL were found to significantly contribute to the risk for CAD. In hypertensive Aggarwal participants, SBP, DBP and waist-to-hip ratio were significant contributors for hypertension; whereas SBP, DBP, and height contributed significantly to risk for hypertension among the Meiteis.

We found marked differences in conventional risk factors between the two ethnic groups. In India, as found elsewhere, the presence of substructuring of groups and hence, genetic isolation is high. More research is needed within this context to unveil the conventional risk factors for complex diseases.