Dietary ω-3 polyunsaturated fatty acid intake modulates impact of Insertion/Deletion polymorphism of ApoB gene on obesity risk in type 2 diabetic patients

•We identified an interaction between ApoB Ins/Del genotypes and n-3 polyunsaturated fatty acid intake.•Participants carrying Del (Ins/Del, Del/Del) may benefit from a diet high in n-3 polyunsaturated fatty acids.•Genetic variants had no significant influence on the change in obesity variables.•The results may contribute to personalized dietary interventions.

ObjectivesThe goal of the study described here was to determine whether dietary ω-3 polyunsaturated fatty acid (PUFA) intake modulates the association between ApoB Ins/Del polymorphism and obesity in type 2 diabetic patients.MethodsIn this cross-sectional study, 700 patients with type 2 diabetes were recruited in Tehran. Weight and waist circumference (WC) were measured, and body mass index (BMI) was calculated. Dietary intake was assessed using a validated semiquantitative food frequency questionnaire. ApoB genotyping was performed with 8% polyacrylamide gel electrophoresis.ResultsWe observed a significant interaction between Ins/Del genotype and dietary ω-3 PUFA intake with respect to BMI, WC, and obesity risk in both unadjusted (P = 0.007, P = 0.001, and P = 0.021, respectively) and adjusted (P = 0.007, P = 0.04, and P = 0.002, respectively) samples. Thus, the carriers of the Del allele were only associated with lower BMI (P = 0.01) and WC (P = 0.002) among individuals with high ω-3 PUFA intake (≥0.6% of energy), but not in those with low ω-3 PUFA intake (<0.6%). Also, when dietary ω-3 PUFA was <0.6%, general obesity risk in carriers of the Del allele was about 1.6 times higher than that of Ins/Ins homozygotes (odds ratio = 1.59, 95% confidence interval: 1.05–2.52, P = 0.039). But with high ω-3 PUFA intake (≥0.6%), the risk was 0.46 times lower (odds ratio = 0.46, 95% confidence interval: 0.25–0.79, P = 0.003). Moreover, a similar interaction was observed in central obesity only in men after adjustment for confounder variables (P = 0.041).ConclusionsThese findings support the hypothesis that a diet high in ω-3 PUFA (≥0.6%) can decrease the obesity risk in carriers of the Del allele of ApoB gene.