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

Molecular Processes in Stress Urinary Incontinence: A Systematic Review of Human and Animal Studies

Stress urinary incontinence (SUI) is a common and burdensome condition. Because of the large knowledge gap around the molecular processes involved in its pathophysiology, the aim of this review was to provide a systematic overview of genetic variants, gene and protein expression changes related to SUI in human and animal studies. On 5 January 2021, a systematic search was performed in Pubmed, Embase, Web of Science, and the Cochrane library. The screening process and quality assessment were performed in duplicate, using predefined inclusion criteria and different quality assessment tools for human and animal studies respectively. The extracted data were grouped in themes per outcome measure, according to their functions in cellular processes, and synthesized in a narrative review. Finally, 107 studies were included, of which 35 used animal models (rats and mice). Resulting from the most examined processes, the evidence suggests that SUI is associated with altered extracellular matrix metabolism, estrogen receptors, oxidative stress, apoptosis, inflammation, neurodegenerative processes, and muscle cell differentiation and contractility. Due to heterogeneity in the studies (e.g., in examined tissues), the precise contribution of the associated genes and proteins in relation to SUI pathophysiology remained unclear. Future research should focus on possible contributors to these alterations.

Treatment with platelet-rich plasma attenuates proprioceptor abnormalities in a rat model of postpartum stress urinary incontinence

INTRODUCTION AND HYPOTHESIS

Stress urinary incontinence (SUI) is the most prevalent form of urinary incontinence, and vaginal delivery is a major risk factor for developing SUI. We evaluated the hypothesis that applying the autologous platelet rich plasma (PRP) to the pelvic floor muscles via injection affects expression of proprioceptors and improves postpartum stress urinary incontinence (PSUI) in rats.

METHODS

Virgin female Sprague-Dawley rats were divided into control (n = 10) and experimental group(n = 20). Vaginal dilation was used to establish PSUI, and the rats in the experimental group were further divided into the PSUI group (n = 10) and PSUI+PRP group (n = 10). Pelvic floor muscles from rats in the PSUI+PRP group were positioned under ultrasound guidance for PRP injection. The morphology and number of pelvic floor muscle spindles were assessed using H&E staining, proprioceptors evaluated by gold chloride staining, and changes in the expression of neurotrophin-3 (NT-3) and skeletal myosin MY-32 determined by immunohistochemistry.

RESULTS

After 28 days,bladder leak point pressure (BLPP) and abdominal leaking-urine point pressure (ALPP) in rats with PSUI were significantly lower than in control animals (P<0.01). Both BLPP and ALPP increased significantly in the PSUI+PRP group (P<0.01). Compared with the control group, muscle spindle morphology and structure in the PSUI and PSUI+PRP groups had different pathological changes,with higher variations in the PSUI group. The positive signals for NT-3/MY-32 expression in control rats were higher than those from PSUI or PSUI+PRP groups, however, the expression for NT-3/MY-32 in PSUI+PRP animals was higher than that seen in the PSUI group (P < 0.01).

CONCLUSIONS

PSUI rats have an abnormal expression of pelvic proprioceptors, which affect proprioceptive function, and further the contractibility of pelvic floor muscles. A PRP injection may restore the sensory function of pelvic proprioceptors, thus improving urine leakage in PSUI rats.

The Onset of Urinary Incontinence in Different Subgroups and its Relation to Menopausal Status: A Hospital-based Study

BACKGROUND/AIM

Numerous risk factors have been reported to influence the development of urinary incontinence (UI). In this study, we took a closer look on the different forms of UI and tried to identify differences in regard to potential risk factors. Of special interest was the onset of UI symptoms and its relation to menopausal status.

PATIENTS AND METHODS

This was a hospital-based analysis of patients who presented with urinary incontinence in the outpatient ward of a tertiary hospital. The diagnosis of urinary incontinence was based on the subjective complaints of patients. Data concerning menopausal status, hormone replacement therapy, prior hysterectomy were assessed.

RESULTS

The mean age was 53.8 years in the SUI group, 62.7 years in the MUI group and 66.1 years in the UUI group, respectively (p<0.001). The proportion of patients with UUI was higher in the postmenopausal group, whereas the proportion of SUI was higher in the premenopausal group (p<0.001). The mean age in which complaints occurred was significantly lower in the SUI group (45.4 years) compared to the MUI (51.0 years) and UUI groups (54.7 years) (p<0.001). There was no correlation between menopausal status and onset of urinary incontinence (p=0.143).

CONCLUSION

Additional anamnestic information help further characterize the different types of urinary incontinence that can lead to an optimization of treatment options. Younger age and premenopausal status were accompanied by milder forms of UI while menopausal status itself had no influence on the onset of UI symptoms indicating that age-related changes may lead to different types of incontinence.