association of body mass index with oxidative stress in patients with type 2 diabetes: do apolipoprotein a-ii -265t > c polymorphism alter this association?

b a ckground:  to compare the oxidative stress (os) factors in obese and non- obese subjects with type 2 diabetes (t2d) and to evaluate the interaction between the apolipoprotein a-ii (apo a-ii) - 265t > c polymorphism and body mass index (bmi) on os factors. m ethods : in this comparative cross-sectional study, 21 diabetes centers in tehran, iran were studied. 180 patients with t2d were divided into two groups of 90 obese (bmi ≥ 30) and 90 non-obese (bmi < 30) with equal numbers of each genotypes of apo a-ii (tt = 30, cc = 30 and tc = 30). superoxide dismutase (sod) activity, total antioxidant capacity (tac) and  8-isoprostane f2α concentration were compared between two groups obese and non-obese and between subjects with and without central obesity. then, the  interaction between the apo  a-ii polymorphism and bmi on os factors were analyzed by general linear model. results : after adjusting for confounding factors, it was observed that the mean of sod activity and tac were lower in the obese group than in the non-obese group (p < 0.050). the mean concentration of 8-isoprostane f2α was not statistically different between the two groups. adjusting for bmi showed that the differences in the mean os factors were not statistically significant between men and women with and without central obesity. it was also observed that the interaction between the apo a-ii polymorphism and bmi on os factors were not significant. conclusion : os level was the higher in obese subjects with t2d than non-obese one.  the  interaction  between  bmi  and  apo  a-ii  polymorphism  had  not  a significant effect on os factors.