Abstract 11743: Association of Waist Circumference with Atherosclerosis among US South Asians: Results from the MASALA Study

Abstract

Background: South Asians (SA) have a disproportionate risk of diabetes and heart disease despite a low prevalence of obesity. There are almost 3 million SA in the United States and SA are currently the second fastest growing U.S. ethnic group after Latinos. Objectives: To examine traditional and adiposity-related factors associated with subclinical atherosclerosis in a community-based sample of SA.

Methods: The Mediators of Atherosclerosis in South Asians Living in America (MASALA) study is a prospective cohort study enrolling 900 SA between 40-79 years without known CVD at two clinical centers (University of California, San Francisco and Northwestern University). Methods for MASALA are similar to the Multi-Ethnic Study of Atherosclerosis. At baseline, we are collecting demographic, cultural and lifestyle information, fasting blood tests, physical examination, carotid ultrasound for intima media thickness (CIMT) and CT for coronary artery calcium (CAC). We created multivariable models with backwards selection to determine correlates of carotid IMT (with linear regression) and any CAC (with logistic regression).

Results: To date, we have enrolled 640 participants in MASALA with a mean age of 56±9 years, of whom 98% are immigrants who have lived in the U.S. an average of 27±11 years. The mean BMI was 26±4 kg/m² and waist circumference was 94±10 cm. The prevalence of hypertension was 45%, 22% had diabetes, and 4% were current smokers. The mean common CIMT was 0.90±0.23 mm, internal CIMT was 1.22±0.46 mm, and 46% had detectable CAC. The table shows associations of significant traditional covariates for common carotid IMT, internal carotid IMT, and any CAC.

Conclusion: In an ethnic group without overt obesity, waist circumference was independently associated with subclinical atherosclerosis. This study of U.S. South Asians will provide insights into novel clinical, behavioral, and socio-cultural factors contributing to atherosclerosis and heart disease.