Stress urinary incontinent women, the influence of age and hormonal status on estrogen receptor alpha and beta gene expression and protein immunoexpression in paraurethral tissues.

Abstract

The underlying cause of stress urinary incontinence (SUI) is an anatomical abnormality associated with paraurethral connective tissue dysfunction. The question as to whether estrogens affect the quality of that tissue remains unexplained. Samples of paraurethral connective tissue from 81 women were examined (the SUI's n = 49; the control's n = 32). In both groups, the patients were subdivided into pre- and postmenopausals. Primary study outcome was comparison of the estrogen receptor alpha (ERα) and the estrogen receptor beta (ERβ) gene and protein in paraurethral tissue between SUI and control group. Secondary study outcome was comparison of these receptors according to hormonal status of the patients and their age. In both examined groups, we found both ER proteins. The ERα gene expression was detected in-19/32 (SUI) samples and in 24/31 (control), and ERβ gene expression 31/32 and 30/31 samples, respectively. The SUI's had significantly lower ERa gene expression premenopausally than the control's. The analysis found considerably lower ERβ and reduced ERα gene expression in postmenopausals, approaches the significance level. There was also significant decrease in both receptors' genes expression in post-53 women, compared to younger patients. Spearman's correlation test revealed a statistically significant decrease in ERβ gene with age. Both estrogen receptors are found in women's paraurethral tissue, so this tissue is an estrogen target. No correlation between ERβ gene expression and immunoexpression and SUI was found. The ERα gene seems to play a key role in SUI in the premenopausal period, but ERβ gene expression in the paraurethral connective tissue decreases with age.