Selected markers of oxidative stress in overweight and obese women - a link between obesity and atherosclerosis
The results of recent studies indicate that obesity is associated with an increase in peroxidation processes. The aim of the present study was to assess the degree of oxidative stress in obese women and to evaluate the relationship between selected markers of oxidative stress and body mass index. Study population consisted of 43 women aged 21 to 66. Subjects were divided into two groups according to their body mass index (BMI): Overweight group (BMI < 30 kg/m2) and Obese group (BMI > 30 kg/m2). Venous blood samples were taken from each subject after an overnight fast and following parameters were assessed: plasma total antioxidant status (TAS), plasma concentrations of thiobarbituric acid reactive substances (TBARS), serum levels of antibodies against oxidized low density lipoproteins (oLAB), serum lipid profiles, serum glucose and insulin concentrations. Additionally, serum low density lipoprotein (LDL) cholesterol and insulin resistance indices were calculated. Serum triglyceride concentrations, insulin levels and insulin resistance indices were significantly higher in obese women in comparison with overweight ones. No significant differences in TBARS concentrations, TAS and oLAB levels were found between the two study groups. However, oLAB titres in Obese group were above the upper limit of the reference range for healthy adults. In both study groups significant correlations (p <0.01) between BMI and levels of triglycerides, insulin concentrations and insulin resistance indices were observed. Additionally, positive correlations (p < 0.05) between BMI and LDL-cholesterol and diastolic blood pressure as well as negative correlations (p < 0.05) between HDL-cholesterol and diastolic blood pressure were found in Obese group. In the overweight women, there were positive correlations between oLAB levels and triglyceride and insulin concentrations, between oLAB titres and insulin resistance indices and between oLAB levels and systolic and diastolic blood pressure (p < 0.01 for all correlations). There was also a negative correlation between oLAB titres and TAS (p < 0.05). The results of the present study confirm that obesity is associated with oxidative stress. Oxidative stress may be the link between obesity and atherosclerosis.