Oxidative Stress, Antioxidant Enzymes and Risk of Hypertension in Obese Type 2 Diabetic Subjects in Osogbo, Osun State, Nigeria

Abstract

Obesity is a chronic disease often associated with type 2 diabetes mellitus (T2DM) and metabolic syndrome. Coexistence of diabetes and hypertension have adverse clinical outcomes with micro and macrovascular complications. This study investigates the relationship of oxidative stress markers and antioxidants with occurrence of hypertension in obese type 2 diabetic subjects in Osun State, Nigeria. Four hundred and forty-five participants made up of 138 non-obese diabetics, 107 obese diabetic subjects attending two tertiary Hospitals in Osogbo in addition to 100 obese non-diabetes (positive controls) and 100 non-obese non-diabetes (negative controls) were enrolled in this study. FBS (9.55±0.13 mmol/l) and HbA1c (9.51±0.15 %) showed highest significant increase in obese diabetic subjects compared to other groups. Mean serum MDA was highest among obese diabetics (p<0.05) while least values of superoxide dismutase (121.09±3.10 µ/ml) and catalase (24.97±0.66 pg/ml) were recorded in non-obese diabetics (p<0.05). 21.0% of non-obese diabetics (n=29), 54.2% of obese diabetics (n=58), 45.0% of obese non-diabetic (n=45) and 21% of non-obese non-diabetics (n=21) were hypertensive. Age, sex, marital status, religion and occupation (χ²=9.856, 8.405, 22.701, 12.066 and 14.468) respectively were all significantly associated with occurrence of hypertension among obese diabetics.  Receiver operating characteristics (ROC) and area under the curve (AUC) showed MDA having the highest cut off point among obese diabetes subject: 0.529 (0.42-0.64 95% CI) with a steep increase in LDL: 0.505(0.40-0.62 95% CI). This study revealed that increased oxidative stress and reduced antioxidant defense enzymes are strongly associated with dyslipidemia among obese diabetic subject.