The effects of the interaction between adiponectin genotype and dietary folate, vitamin B6 and vitamin E on serum TNF‐α level in the patients with type 2 diabetes

Abstract

Adiponectin is known to relate with insulin resistance and CVD risk due to its anti‐inflammatory effect. To evaluate the effect of interaction between the adiponectin genotype and nutrient factors on tumor necrosis factor‐α (TNF‐α), SNP 276G→T at adiponectin gene was evaluated by a PCR‐RFLP analysis and TNF‐α was measured by ELISA kit. Dietary intakes were analyzed by using semi‐quantitative food frequency questionnaire. Sex, age, BMI, smoking, and alcohol drinking were used for adjustment and energy intake was used only in the analysis of dietary factors. 569 patients with T2D (287 males and 282 females) were enrolled, whose prevalence of G/G, G/T and T/T genotype was 45.9%, 45.7% and 8.4%, respectively. TNF‐α was correlated with HbA1c (r=0.237, P<0.0001), KITT, an insulin resistance index (r=−0.160, P<0.0001), atherosclerosis index (r=0.104, P<0.05) and log‐transformed intakes of dietary folate (r=−0.156, P<0.0001), vitamin E (r=−0.145, P<0.01) and vitamin B6 (r=−0.123, P<0.01). However negative relationships between above vitamins and TNF‐α were significant only in the G/G genotype (P‐values for trend were <0.0001, <0.001, and <0.01, respectively). In conclusion, dietary vitamins could reduce serum TNF‐α, a risk factor of insulin resistance and CVD, and it could be more effective in the T2D patients with normal adiponectin genotype. This work was supported by the Brain Korea 21 project.