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

OBJECTIVES: The 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. METHODS: In 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. RESULTS: We 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). CONCLUSIONS: These 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.

Efficacy of omega-3 fatty acid supplementation on serum levels of tumour necrosis factor-alpha, C-reactive protein and interleukin-2 in type 2 diabetes mellitus patients.

INTRODUCTION: Consumption of omega-3 fatty acids can alter the inflammatory response in diabetic patients. This study aimed to determine the effects of omega-3 fatty acid supplementation on the serum levels of C-reactive protein (CRP), interleukin (IL)-2 and tumour necrosis factor-alpha (TNF-α) in type 2 diabetes mellitus patients. METHODS: A randomised, double-blind, placebo-controlled clinical trial was conducted on 84 subjects aged 45-85 years with at least a two-year history of type 2 diabetes mellitus. Participants were randomly assigned to the treatment or control group. Each subject in the treatment group received three omega-3 capsules per day (eicosapentaenoic acid 1,548 mg; docosahexaenoic acid 828 mg; other omega-3 fatty acids 338 mg), while each subject in the control group received three placebo capsules (sunflower oil 2,100 mg) for a period of eight weeks. At the beginning of the study and post intervention, fasting blood samples were taken and serum concentrations of IL-2, TNF-α and CRP were assessed and compared. RESULTS: Serum IL-2 and TNF-α levels were significantly reduced in the treatment group compared to the controls (p < 0.01). There was no significant change in serum CRP levels. CONCLUSION: Short-term omega-3 fatty acid supplementation (3 g/day for eight weeks) can decrease the serum levels of TNF-α and IL-2 in diabetic patients, with no change in CRP levels. Consumption of omega-3 fatty acid supplements is highly recommended to alleviate inflammation caused by type 2 diabetes mellitus.