Can Conventional Risk Factors Explain Excess Coronary Artery Disease Risk in South Asians: Dyslipidemias and Dysfunctional High Density Lipoprotein (HDL)

Abstract

Over the past several years, the overall prevalence and incidence of cardiovascular diseases in general and coronary artery diseases (CAD) in particular have declined in the United States (US). However, among South Asian in general and South Asian immigrants in particular, a disturbing trend toward high rates of CAD has been noted. This trend is associated with a high prevalence of conventional risk factors and metabolic syndrome in this population, yet these conventional risk factors may not account for the greater CAD risk among SAIs. A search for additional markers is war- ranted, to enable early detection and prevention of CAD in this high risk group. High density lipoprotein (HDL) is one of the predictor of CAD and is considered to be cardio-protective. However, some of the recent studies have shown that HDL is not only ineffective as an antioxidant but, paradoxically, appears to be pro-oxidant, and has been found to be asso- ciated with CAD. Such HDL is called dysfunctional HDL. More research is required in South Asians to explore associa- tions with CAD and to enhance early detection and prevention of CAD in this high risk group. We present here an over- view on risk factors of CAD in general and dyslipidemias in particular in South Asians. In addition, concepts on dysfunc- tional HDL and its impact on CAD are also presented. At the end, recommendations are made to improve and prevent CAD morbidity and mortality in the South Asian communities. The high rates of CAD among South Asian immigrants are not limited to the United States and appear to be part of a global phenomenon (10). Further, CAD risk factors are pre- sent in South Asians at a younger age compared to other populations, resulting in CAD at a younger age than in other populations (3). The reasons for early development of CAD risk factors at a relatively young age in South Asian immi- grants are still unclear.