Endocrine status and markers of collagen synthesis and degradation in serum and urogenital tissue from women with and without stress urinary incontinence

Abstract

To investigate possible differences in androgen/estrogen status between patients with stress urinary incontinence (SUI) and healthy women's and to study possible associations between circulating estrogens and androgens on the one hand and collagen synthesis and metabolism in urogenital tissue on the other. Markers of collagen turnover, the carboxy-terminal propeptide of type I procollagen (PICP), the carboxy-terminal telopeptide of type I collagen (ICTP), and the amino-terminal propeptide of procollagen III (PIIINP), were assayed in urogenital tissue homogenates and estradiol-17beta (E2), total testosterone (T), and sex-hormone-binding globulin (SHBG) were assayed in peripheral serum from 58 patients with SUI and 30 urologically healthy women. Apparent concentrations of free testosterone (fT) were calculated from T, SHBG, and a fixed albumin value. Significant positive correlations were found between E2 and PICP in controls and between E2 and ICTP in SUI patients without exogenous hormones. Significant negative and sometimes strong correlations were found between serum T and fT on the one hand and all three collagen turnover markers on the other. These correlations were strengthened when parity and/or body mass index (BMI) were reduced. No correlations between T and fT and collagen turnover markers were found in the controls. There were no significant differences between any of the groups in serum E2, T, or fT. Estrogens may increase collagen turnover in urogenital tissue, however, the clinical significance of this is still unclear. Androgens may affect urogenital tissue negatively by slowing down collagen turnover, probably by inhibition of matrix metalloprotease (MMP) synthesis and/or activity. Urogenital tissue in SUI patients and in urologically healthy women may differ in androgen sensitivity.