Lipid profile, plasma apolipoproteins, and risk of a first myocardial infarction among Asians: an analysis from the INTERHEART Study.

OBJECTIVES This study sought to determine the prevalence of lipid and lipoprotein abnormalities and their association with the risk of a first acute myocardial infarction (AMI) among Asians. BACKGROUND Patterns of lipid abnormalities among Asians and their relative impact on cardiovascular risk have not been well characterized. METHODS In a case-control study, 65 centers in Asia recruited 5,731 cases of a first AMI and 6,459 control subjects. Plasma levels of lipids and apolipoproteins in the different Asian subgroups (South Asians, Chinese, Southeast Asians, and Japanese) were determined and correlated with the risk of AMI. RESULTS Among both cases and controls, mean low-density lipoprotein cholesterol (LDL-C) levels were about 10 mg/dl lower in Asians compared with non-Asians. A greater proportion of Asian cases and controls had LDL-C </=100 mg/dl (25.5% and 32.3% in Asians vs. 19.4% and 25.3% in non-Asians, respectively). High-density lipoprotein cholesterol (HDL-C) levels were slightly lower among Asians compared with non-Asians. There was a preponderance of people with low HDL-C among South Asians (South Asia vs. rest of Asia: cases 82.3% vs. 57.4%; controls 81% vs. 51.6%; p < 0.0001 for both comparisons). However, despite these differences in absolute levels, the risk of AMI associated with increases in LDL-C and decreases in HDL-C was similar for Asians and non-Asians. Among South Asians, changes in apolipoprotein (Apo)A1 predicted risk better than HDL-C. ApoB/ApoA1 showed the strongest association with the risk of AMI. CONCLUSIONS The preserved association of LDL-C with risk of AMI among Asians, despite the lower baseline levels, suggests the need to rethink treatment thresholds and targets in this population. The low HDL-C level among South Asians requires further study and targeted intervention.