Is obesity associated with increased plasma lipid peroxidation and oxidative stress in women?

The role of obesity in diabetes mellitus, hyperlipidemia, colon cancer, sudden death and other cardiovascular diseases has been confirmed by many studies. In this study, it was hypothesized that obesity is an independent risk factor for lipid peroxidation and decreased activity of cytoprotective enzymes in humans. To test the study hypothesis, we assessed lipid peroxidation by measuring the concentrations of plasma malondialdehyde [MDA] and the activity of erythrocyte copper-zinc superoxide dismutase [CuZn-SOD], glutathione peroxidase [GPX] and catalase [CAT] in 25 obese women [BMI=30-40 Kg/m2] and 25 women with healthy BMI [19-25Kg/m2]. The concentration of plasma MDA was significantly higher [P<0.001] in obese women [3.4 +/- 0.7 micro mol/L] compared to women with healthy BMI [1.4 +/- 0.3 micro mol/L]. Furthermore, there was a significantly positive correlation [r =0.75, P<0.0001] between BMI and plasma MDA. On the other hand, women with healthy BMI had significantly higher [P<0.001] erythrocyte CuZn-SOD [873 +/- 52 U/g Hb] and GPX [64.7 +/- 14.2 U/g Hb] activity than obese women [660 +/- 39 U/g Hb] and [48.5 +/- 13.1 U/g Hb], respectively. Furthermore, erythrocyte CuZn-SOD and GPX activity were negatively correlated with BMI [r =-0.52, P<0.0001 and r =-0.42, P<0.001], respectively. No significant difference was observed between two groups in erythrocyte CAT activity. We conclude that obesity, diabetes, renal or liver disease can decrease the activity of protective antioxidants and can enhance the systemic oxidative stress even in the absence of smoking

Efect of modest weight loss on cardiovascular inflammatory markers in obese women

Obesity is associated with an increased risk of coronary heart disease. It is believed that adipose tissue inflammatory substances contribute to the pathogenesis of cardiovascular disease. To find out the metabolic benefits of weight loss in reducing cardiovascular risk, we assessed the effect of modest weight loss on plasma inflammatory markers in obese women. In a clinical trial, 42 obese women underwent a 10 week restricted diet program. Body weight, fasting glucose, insulin, total cholesterol, triglyceride, high-density lipoprotein cholesterol [HDL-c], low-density lipoprotein cholesterol [LDL-c] and plasma inflammatory cytokines were measured at baseline and after 10 weeks. Weight, BMI, fasting blood glucose, insulin, cholesterol and triglyceride had significant reductions. No significant changes were observed in HDL-c and LDL-c concentrations. All plasma inflammatory proteins improved significantly except CRP level. Modest weight loss [almost equal to 5%] is associated with favorable changes in plasma inflammatory markers