The present study investigated whether a predisposition to high frequency of small, dense low density lipoproteins (LDL) could be an additional coronary risk factor in migrant Asian Indians. Ninety-three normolipidemic (fasting plasma cholesterol levels < or = 240 mg/dl and triglyceride levels < or = 250 mg/dl) adult Asian Indian men residing in the U.S. were compared to a group of 59 Caucasian men for the prevalence of LDL electrophoretic patterns A and B (size of major LDL peak > or = 255 A for LDL pattern A and < 255 A for LDL pattern B). Compared to the Caucasians, the Asian Indians had larger LDL size (mean +/- SD; 260.1 +/- 12.8 A vs 267.7 +/- 11.4 A, respectively; p = 0.0002), an increased frequency of LDL pattern A (59% vs 85%, respectively) and a lower frequency of LDL pattern B (41% vs 15%, respectively) (p = 0.0005). The difference in LDL size in the two study groups persisted after adjusting for the various confounding variables, such as age, plasma triglycerides, high-density lipoprotein cholesterol and dietary habits. We conclude that compared to Caucasians, Asian Indian men have larger LDL particles and a lower prevalence of LDL phenotype B in the presence of normolipidemia. Therefore, we exclude a genetic predisposition to atherogenic LDL phenotype as a factor contributing to the high incidence of coronary heart disease in migrant Asian Indians.