Coronary artery disease and diabetes - Indian scenario

Abstract

Coronary artery disease (CAD) and diabetes have emerged as the major causes of mortality worldwide as the toll of infectious diseases have begun to wane. Escalation in prevalence of both these conditions appears to be more pronounced in developing countries, particularly in India. Ample evidence has accumulated for the high prevalence rates of diabetes and CAD among Indians. Both these diseases could rise from a common soil. It has been shown thai the risk for CAD among diabetic subjects is greater by a factor of 2 to 4 compared to non-diabetic subjects. The Asian Indian paradox' is that high rates of CAD are seen despite low rates of conventional risk factors like obesity, smoking and hypertension. Therefore there is a great need for studying risk factors for CAD among Indians. The prevalence of CAD in the Chennai Urban Population Study (CUPS), a population based study is 11% which is 10 times higher than that reported 40 years ago. Diabetic subjects in this study had a two fold higher risk for CAD compared to the subjects with normal glucose tolerance. The reason for the enhanced susceptibility for CAD among diabetic subjects is still not clear. As diabetes is a part of the insulin resistance cluster, which is a combination of hyperglycemia, central body obesity, dyslipidemia, and hypertension, there could be an interplay of these factors in enhancing the chances of developing CAD. In addition, low-grade inflammation due to insulin resistance contributes to plaque formation and rupture. This review discusses the role of a variety of cardiovascular risk factors in contributing to the excess CAD in diabetic patients with particular reference to the Indian subcontinent.