It is an established fact that diabetes induces 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. Materials and Methods: 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, α-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. Results: Mean±SD plasma α-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 αtocopherol 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. Conclusion: 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.
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