Plasmatic and Intracellular Markers of Oxidative Stress in Normal Weight and Obese Patients with Polycystic Ovary Syndrome

Abstract

Introduction Insulin resistance (IR) is associated with polycystic ovary syndrome (PCOS). Oxidative stress (OS) is, in turn, related to IR. Studies in PCOS evidenced an increase in OS markers, but they are mainly performed in obese patients, while the complex picture of normal weight PCOS is still poorly investigated. Matherials and Methods To investigate OS in PCOS and relationship with hormonal and metabolic picture, we performed a case-control study in 2 PCOS groups: normal weight (N-PCOS, n=21, age 18-25 ys, mean±SEM BMI 20.7±0.2 kg/m²) and obese (OB-PCOS, n=15, 20-30 ys, BMI 32.8±1.1), compared with control groups matched for BMI: normal (N-C, n=10, 20-30 ys, BMI 21.6±0.9) and obese (OB-C, n=20, 21-31ys, BMI 36.8±1.0). Malondialdehyde (MDA) in blood plasma and peripheral mononuclear cells, obtained by density-gradient centrifugation, was assayed spectrophotometrically by TBARS assay. CoenzymeQ₁₀ (CoQ₁₀) in plasma and cells was assayed by HPLC. Plasma Total Antioxidant Capacity (TAC) was also measured by spectrophotometric method. Results PCOS patients exhibited higher Testosterone levels than controls, but OB-PCOS had highest HOMA (Homeostasis Model Assessment) index, suggesting marked insulin resistance. Despite plasma MDA levels were not significantly different (N-PCOS 3380±346.94 vs. N-C 7 120±541.66; OB-PCOS 5 517.5±853.9 vs. OB. 3 939.66±311.2 pmol/ml), intracellular MDA levels were significantly higher in N-PCOS than controls (mean 3 259±821.5 vs. 458±43.2 pmol/10⁶/cells) and higher than OB-PCOS, although not significantly (1363.1±412.8 pmol/10⁶/cells). Intracellular CoenzymeQ₁₀ was higher in N-PCOS than in N-C, but the highest levels were found in OB-C. Conclusions Our data, while confirming the presence of OS in obese PCOS patients in agreement with literature, suggest that OS could be present also in normal weight PCOS, but it can be revealed in tissue rather than in plasma. The relationship with metabolic status remains to be established, but could be a physiopathological basis for antioxidant treatment in such patients.