We investigated the frequency of apolipoprotein E (apoE) polymorphism and the effect of apoE polymorphism on plasma lipid and lipoprotein levels under different nutritional statuses in Vietnamese children living in urban and rural areas. Three hundred and forty-eight girls (aged 7 to 9 years) were randomly selected from urban and rural areas in southern Vietnam. Their apoE genotypes were analyzed by an Invader assay, and the plasma lipid and lipoprotein levels were determined by enzymatic methods using fasting blood samples. Dietary intake and anthropometry of children were also measured. The frequency of the allele 2 Euro and 4 Euro of the Vietnamese girls was 0.09 and 0.12, respectively. The levels of low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) of the allele 2 Euro carriers were significantly lower than those of the allele 3 Euro carriers (P < .0001) in both the urban and rural groups. In contrast, the allele 4 Euro carriers tended to show a higher LDL-C level than the allele 3 Euro carriers, especially in subjects with a higher fat intake in urban area. The allele 2 Euro carriers had the same high-density lipoprotein cholesterol (HDL-C) and triglyceride (TG) level as the allele 3 Euro carriers, but the allele 4 Euro carriers with a higher fat intake living in urban areas had lower HDL-C and higher TG level than allele 3 Euro carriers. In conclusion, our findings showed that the LDL-C lowering effect of allele 2 Euro was independent of the nutritional status, while allele 4 Euro tended to lower HDL-C and increase the LDL-C level in a high-fat intake population. Therefore, the plasma lipid profiles of apoE 4 Euro carriers may be a risk factor of atherogenesis in Vietnamese, who tend to have a westernized eating habit. (C) 2004 Elsevier Inc. All rights reserved.