Objective: Heterogeneity in circulating lipid concentrations in response to different dietary fat intakes may be due, in part, to gene polymorphism of cytokine related to inflammation. The objective was to determine whether dietary n-3 PUFAs intake influenced the effects of IL-6 -572 polymorphism on plasma lipids and apolipoproteins.
Study design: This cross-sectional study included 195 men and 386 women aged 40-65 y. DNA was isolated from white blood cell to determine the IL-6 -572 C-G polymorphisms by the polymerase chain reaction-logation detection reaction (PCR-LDR) method. Dietary fatty acids were assessed by measuring erythrocyte membrane fatty acids, and fasting plasma was collected to determine blood lipids and apoproteins.
Results: The frequency of the G allele was 0.214. There were no significant differences in plasma lipids across genotypes (all p > 0.05). When men and women were grouped into tertiles by the erythrocyte membrane n-3 PUFAs composition; in the lowest group, men with G allele had 18% higher HDL-cholesterol concentrations than did C/C genotype (p < 0.05). Similar effects were observed for apo A. Adjusting for age, BMI and total PUFA did not alter this association. The interaction was not significant in women.
Conclusion: Dietary n-3 PUFA intake influenced the effects of IL-6 -572 genotype on HDL-c concentrations in males.