Abstract P199: Mean Lipoprotein Levels and Composition in South Asian-Americans Compared to the US Population
Background South Asians have increased disk for cardiovascular disease (CVD) that is not captured by traditional risk factors, including TC and LDL-c. Low-density apolipoprotein-B (apoB) containing lipoproteins are heterogeneous in size and composition, and the particles with the greatest triglyceride content are thought to ultimately be the most atherogenic. Specific composition of low-density lipoproteins is not captured by common lipid measures (i.e. TC, LDL-c). A high proportion of triglyceride-rich low-density lipoproteins could be a mechanism for CVD risk in South Asians. Our objective was to compare mean TC, LDL-c, HDL-c, triglycerides, and apoB-triglyceride ratio (an estimate of low-density lipoprotein content) between South Asian-Americans and the US population.
Methods We studied 2,876 South Asian adults living in the United States participating in a wellness program. Demographics were obtained by self-report. Lipoprotein levels were measured after 10-hour fast. US population means were calculated from NHANES (2007-2008, n = 5,113). Individuals on lipid-lowering therapy were excluded (780 (33%) South Asians, 1,194 (19%) NHANES).
Results LDL-c (118mg/dL vs 116mg/dL, p<0.05) and triglycerides (139mg/dL vs 131 mg/dL, p<0.05) were higher in South Asians than the US population, whereas TC was lower (192mg/dL vs 197 mg/dL, p<0.05). HDL-c was lower in South Asians (46mg/dL vs 52mg/dL, p<0.05). ApoB was not statistically significantly different (93mg/dL vs 92mg/dL, p = 0.1), however the apoB/triglyceride ratio was lower in South Asians (0.8 vs 0.9, p<0.05). After stratifying for age by decade and gender, we found that South Asians have lower HDL-c until the age of 50, and lower apoB/triglyceride ratio until the age of 60, with no substantial differences between men and women.
Conclusions Mean TC, LDL-c, and triglycerides were normal in South Asians, however the apoB/triglyceride ratio was lower in South Asians than in the US population. This finding indicates that a higher proportion of low-density lipoproteins in South Asians are of the triglyceride-rich atherogenic type. This may portend non-HDL-c as a better indicator of CVD risk than LDL-c in South Asians. Further, low apoB/triglyceride ratio and low HDL-c occurs at a young age in South Asians, suggesting that onset of risk is early. The disappearance of these patterns after age 60 may be the result of sample bias (excluding individuals on lipid lowering therapy), and/or survival bias.
- © 2012 by American Heart Association, Inc.