Increased serum oxidative stress markers in women with uterine leiomyoma

Abstract

Background: Uterine leiomyomas (fibroids) are the most common gynaecological benign tumors in premenopausal women. Evidences support the role of oxidative stress in the development of uterine leiomyoma. We have analysed oxidative stress markers (thiols, advanced oxidized protein products (AOPP), protein carbonyls and nitrates/nitrites) in preoperative sera from women with histologically proven uterine leiomyoma.

Methodology/principal findings: We conducted a laboratory study in a tertiary-care university hospital. Fifty-nine women with histologically proven uterine leiomyoma and ninety-two leiomyoma-free control women have been enrolled in this study. Complete surgical exploration of the abdominopelvic cavity was performed in each patient. Preoperative serum samples were obtained from all study participants to assay serum thiols, AOPP, protein carbonyls and nitrates/nitrites. Concentrations of serum protein carbonyl groups and AOPP were higher in leiomyoma patients than in the control group (p=0.005 and p<0.001, respectively). By contrast, serum thiol levels were lower in leiomyoma patients (p<0.001). We found positive correlations between serum AOPP concentrations and total fibroids weight (r=0.339; p=0.028), serum AOPP and serum protein carbonyls with duration of infertility (r=0.762; p=0.006 and r=0.683; p=0.021, respectively).

Conclusions/significance: This study, for the first time, reveals a significant increase of protein oxidative stress status and reduced antioxidant capacity in sera from women with uterine leiomyoma.

Figure 1. Serum oxidative stress parameters in women with uterine leiomyoma and in controls.

A) Serum Thiols (µmol/l). B) Serum AOPP (µmol/l). C) Serum protein carbonyls (nmol/mg). D) Serum Nitrates/Nitrites (µmol/l). Statistical analysis was performed using the Mann-Whitney U. Serum oxidative stress parameters are represented as boxes and whisker plots. The bottom and top of the boxes represent the interquartile range (the 25th and 75th percentile, respectively), and the band near the middle of the box is the median. The ends of the whiskers represent the minimum and maximum of all the data. P < 0.05 was considered statistically significant.

Figure 2. Correlation between serum oxidative stress parameters and anatomical parameters of uterine leiomyoma.

A) Serum AOPP levels and Total Fibroids Weight (g), B) Serum AOPP levels and infertility duration, C) Serum Protein Carbonyl levels and infertility duration. Nonparametric Spearman’s correlation test was used to assess correlations.