Relationship between plasma antioxidant status and leptin in controlled and non-controlled type 2 diabetic non-obese women

ABSTRACT

It is an established fact that diabetes in-duces oxidative stress; obesity is associated with type 2 diabetes mellitus [T2DM] and increased leptin levels. Insulin has been suggested to be a regulator of in vivo leptin secretion, while hyperinsulinaemia is a feature of T2DM. Our study aimed at determining the relationship between plasma antioxidant status and leptin in controlled and non-controlled T2DM non obese women. Sixty-five non-obese [BMI <26kg/m2] women with T2DM, 34 controlled [HbA1c <6%] and 31 non-controlled [HbA1c >8%], between the ages of 25-55 years were recruited for the study. Plasma levels of leptin, alpha-tocopherol, retinol, total antioxidant status [TAS], lipid peroxidation [Malondialdehyde [MDA]], fasting plasma glucose [FPG], glycosylated haemoglobin [HbA1c%], total cholesterol [TC], HDL-cholesterol, LDL-cholesterol and triglyceride [TG] were determined for all enrollees. Mean +/- SD plasma alpha-tocopherol and TAS for non-controlled T2DM subjects were significantly reduced compared to the controlled [p<0.01]. However, the mean +/- SD plasma leptin and MDA for the non-controlled T2DM subjects were significantly increased compared to the controlled group [p<0.01]. The analysis for association between leptin and TAS shows an inverse correlation for the controlled [r-0.23, p<0.05] and for the non-controlled [r-0.51, p<0.01] T2DM group. Likewise, there was an inverse correlation between leptin and alpha-tocopherol for the controlled [r-0.25, p<0.05] and for the non-controlled [r-0.49, p<0.01] T2DM groups. However, a direct correlation between leptin and MDA was found for the controlled [r=0.21, p<0.05] and for the non-controlled [r=0.47, p<0.01] T2DM subjects. Our findings suggest that oxidative stress and leptin are associated with risk of T2DM and could be a target for insulin sensitization to prevent diabetes and its complications