Association of C-reactive protein with body fat, diabetes and coronary artery disease in Asian Indians: the Chennai Urban Rural Epidemiology Study (CURES-6)

Abstract

Objective: The aim of the study was to determine the association of high sensitivity C-reactive protein (hs-CRP) with body fat, diabetes and coronary artery disease (CAD) in an urban south Indian population. Design: The study was conducted on 150 subjects selected from the Chennai Urban Rural Epidemiology Study (CURES), an ongoing population-based study on a representative population of Chennai (formerly Madras). Group 1 comprised of non-diabetic subjects without CAD (n = 50). Type 2 diabetic subjects without CAD formed Group 2 (n = 50); Group 3 comprised of Type 2 diabetic subjects with CAD (n = 50). CAD was diagnosed based on electrocardiographic (ECG) changes suggestive of ST segment depression and/or Q wave changes using appropriate Minnesota codes. All study subjects were non-smokers, and had no infectious or inflammatory diseases. The plasma levels of hs-CRP were measured using a highly sensitive nephelometric assay. Body fat was calculated using Siri's formula using skin fold measurements. Results: Diabetic subjects with (2.89 mg/l) and without (2.25 mg/l) CAD had significantly higher hs-CRP levels compared with non-diabetic subjects without CAD (0.99 mg/l, P < 0.001). hs-CRP values increased with increases in tertiles of body fat (anovaP < 0.001) and HbA_1c (anovaP < 0.001). Multiple logistic regression analysis revealed hs-CRP to be strongly associated with CAD (OR: 1.649, P = 0.040) and diabetes (OR: 2.264, P = 0.008) even after adjusting for age and gender. Regression analysis also revealed body fat to be strongly associated with diabetes and CAD even after adjusting for age and gender (P < 0.001). hs-CRP influenced this association for diabetes but not for CAD. Conclusion: hs-CRP showed a strong association with CAD and diabetes, even after adjusting for age and gender. The association of body fat with diabetes seems to be mediated through hs-CRP. However, hs-CRP does not appear to mediate the relationship between body fat and CAD.