Association between plasma lipid parameters and APOC3 genotypes in Brazilian subjects: effect of gender, smoking and APOE genotypes

Abstract

Background: APOC3 polymorphisms were associated with lipid parameters and coronary artery disease in several populations but not all. Considering the multifactorial inheritance and environmental factors that underlie the determination of triglyceride (TG) and HDL-C levels, the aims of the present study were to perform association analyses of APOC3 polymorphisms and these lipids in a southern Brazilian population of European descent to investigate possible interactions with other genetic and/or environmental factors.

Methods: Six hundred and seventy-three subjects participated in the study. -482C>T, -455T>C and 3238C>G polymorphisms genotyping were carried out by PCR followed by restriction enzyme digestion.

Results: In female subjects the APOC3-APOE genotype combinations had a significant effect on triglyceride levels (ANOVA, P=0.009). Post hoc analysis showed that the observed differences were between APOC3 S(*)2 carriers and S(*)1S(*)1 homozygotes in individuals with an APOE(*)3/3 genotype (Tukey HSD post hoc test, P=0.027). In APOE(*)3/(*)3 subjects, the raising effect of APOC3 S(*)2 allele on TG concentrations was more pronounced in female smokers (+59.4%) than in nonsmokers (+18.8%, P of S(*)2-smoking interaction=0.009). Among APOE(*)3/(*)3 subjects, male carriers of the less common alleles -482T and -455C had significant lower levels of HDL-C compared to homozygotes -482C/C and -455T/T (P=0.02 and P=0.006, respectively).

Conclusion: APOC3 polymorphisms were associated with lipid variables, but the magnitude of these associations was modulated by additional genetic, biologic and/or environmental factors.