Endocrine Abstracts

Introduction: Polycystic ovary syndrome (PCOS) is usually accompanied by abdominal obesity and insulin resistance which are related with low-grade chronic inflammation, as evidenced by elevation of multiple markers of inflammation, among which is oxidative stress. However, as far as oxidative stress presence, the existing data are limited. The purpose of this study was the investigation of several oxidative stress markers in women with PCOS without insulin resistance.

Material and Methods: 15 patients with PCOS according to NIH criteria (1990) and 10 women matched for age and BMI, with normal cycles and without clinical or biochemical hyperandrogenemia were studied. Somatometric parameters were recorded and androgen, SHBG, insulin and blood glucose levels were measured after an overnight fast. Free androgen index (FAI) and homeostatic model assessment of insulin resistance (HOMA-IR) were calculated. Among oxidative stress markers, catalase (CAT) and superoxide dismutase (SOD) activity were determined, total antioxidant capacity (TAC), glutathione levels (GSH), lipid peroxidation by thiobarbituric acid reactive substances (TBARS) and nitrogen monoxide (NOx) levels were assessed in peripheral blood. Statistical analysis was performed with logistic SPSS 16.0.

Results: Patients and controls were comparable regarding age, BMI (22.6±2.8 vs 20.5±2.2 kg/m², P>0.05) and the level of insulin resistance as expressed by HOMA-IR (2.09±1.0 vs 1.6±0.5, P>0.05). As expected, androgen levels were higher while sex hormone-binding globulin levels were lower in patients with PCOS, compared to control group (P<0.01). Oxidative stress as evidenced by lipid peroxidation and TAC was not different in women with PCOS compared to controls. However, a significant increase in CAT and SOD activity was observed, indicating an inner stress- counterbalanced effect (P<0.01). CAT activity was positively correlated with total testosterone (P=0.019) and D4-androstendione (P=0.008) levels, while SOD activity was positively correlated with total testosterone (P<0.001), D4-androstendione (P=0.001), DHEA-S (P=0.023) and glucose (P=0.02) levels and negatively with SHBG (P=0.001) levels.

Conclusions: These preliminary results show that, oxidative stress is not increased in women with PCOS without insulin resistance, probably due to its sufficient counterbalance by the inner antioxidant response. Insulin resistance may be a factor that is crucially involved in the aggravation of pro-inflammatory oxidative stress.