Dose-response of Physical Exercise on Pelvic Floor Muscle Function in Postmenopausal Women With Urinary Incontinence

Urinary incontinence (UI) symptoms are highly prevalent among women, and menopause is one of the risk factors for UI. During the menopausal transition, not only the hormonal secretion is changed but also the level of physical activity is affected. The time spent on physical activity is reduced in postmenopausal women. Studies have shown that physical activity acts in a bidirectional manner, exerting either a preventive or an aggravating effect on urinary incontinence. Individuals with sedentary lifestyle and insufficient physical activity (\< 150 min/week) are at risk of developing UI, and regular physical activity exerts a protective effect in preventing UI, but the optimal type, duration, and intensity of exercise for the female older adult population remain unknown. In addition, objective measurements of pelvic floor muscle function is needed as the use of self-reported measures may cause response bias. The aim of the study is to investigate the effect of different intensity of exercise on pelvic floor muscle function and HRQoL in postmenopausal women with UI. The investigators hypothesize that (a) both high- and low-intensity physical activities can improve pelvic floor muscle strength and HRQoL in postmenopausal women with UI, and (b) the improvement in high-intensity group is higher than that in low-intensity group. A randomized trial will be conducted to compare the effect of different exercise intensity on pelvic floor muscle function in postmenopausal women with urinary incontinence (n=90).

In Taiwan, the prevalence of urinary incontinence (UI) in postmenopausal women was 29.8%. Previous studies have indicated that menopause may be associated with developing UI. As there are many estrogen receptors in pelvic floor, the estrogen decline after menopausal transition may lead to pelvic floor muscle dysfunction, and the subsequent development of UI. Pelvic floor muscle training (PFMT) has been recommended by the International Continence Society as the first-line conservative treatment for women with UI. In addition to the prevalent incontinence associated with postmenopausal status, many women tend to have a more sedentary lifestyle after menopausal transition. Previous studies have shown that a sedentary lifestyle is related to UI in older women and indicated the importance of physical activity on preventing incontinence. Regular physical exercise including aerobic exercise and resistance training has been proved to improve bone mineral density, stress management and autonomic functions in postmenopausal women. However, the effect of different intensity of physical exercise adding to PFMT on pelvic floor muscle function in postmenopausal women with UI remains unknown. Therefore, the aim of this study is to investigate the effect of different intensity of exercise on pelvic floor muscle function and health-related quality of life in postmenopausal women with UI.

This is a randomized controlled trial (RCT). Postmenopausal women with UI and a sedentary lifestyle will be recruited. Eligible participants will be randomly allocated to the high-intensity group to receive high intensity general exercise plus PFMT program, the low-intensity group to receive low intensity general exercise plus PFMT, or the control group to receive only PFMT. The intervention will be provided twice weekly for eight weeks. The assessments will be conducted at baseline and after 8-week intervention. The primary outcome is pelvic floor muscle function measured by manometry and through digital palpation. The secondary outcomes are symptom severity measured using the International Consultation on Incontinence Questionnaire -Urinary Incontinence Short Form (ICIQ-UI SF), health-related quality of life measured using the International Consultation on Incontinence Questionnaire Lower Urinary Tract Symptoms Quality of Life Module (ICIQ-LUTSqol), and physical activity levels measured by the International Physical Activity Questionnaire (IPAQ). In addition, the participants will be asked to complete a 3-day bladder diary. Data analysis will be performed using Statistical Product and Service Solutions (SPSS) version 22.0. For continuous data, analysis of covariance tests will be used for within-group and between-group comparisons, respectively. For categorical data, McNemar's tests and chi-square tests will be used for within-group and between-group comparisons. The significant level is set at p-value \< 0.05.

Eligibility Criteria:
Inclusion Criteria:

* Postmenopausal women: amenorrhoea for longer than 12 months.
* Symptomatic UI: The questionnaire for urinary incontinence diagnosis (QUID) score \>0
* Sedentary lifestyle: \< 150 minutes of moderate-intensity aerobic physical activity throughout the week, or \< 75 minutes of vigorous-intensity aerobic physical activity throughout the week, or an equivalent combination of moderate and vigorous-intensity activity
* Able to answer the questionnaire correctly (no language barrier or cognitive problems)
* No other physical or psychological problem that would interfere participation in the study
* No concurrent outpatient rehab attendance / supervised exercise

Exclusion Criteria:

* Use hormone therapy
* Age \>80 y/o
* Neurological condition: Spinal cord injury, multiple sclerosis, transverse myelitis, cerebrovascular accident
* Radical surgery for pelvis, sling, and prolapse surgery
* Malignancy for bladder, urethra, uterus, ovary, cervix, and rectum
* Overflow incontinence or voiding dysfunction