Clinical Consult

Each month, questions with a common theme will be selected and answered comprehensively by one of our Steering Committee members. Previously answered questions will be archived each month for your reference. If you wish to submit a question, click here.

This Month's Question:

Why does the prevalence of urinary incontinence (UI) increase with age, and what treatment strategies are available to effectively manage UI in the older woman?

Response by Thelma J. Wells, PhD, RN, posted 10/19/2005:

Stress urinary incontinence (SUI), the most common form of UI, affects about one half of women with UI. Both urge urinary incontinence (UUI) and mixed urinary incontinence, the latter being the second most prevalent form of UI, are more prevalent with increasing age. In terms of their relative prevalence, SUI is more common in younger women, whereas both UUI and mixed UI are more common in older women.^1-3

A number of investigators have explored the association of increased risk of UI with a variety of physiological changes and comorbidities that are linked to advancing age, as well as with traumatic injuries to the female (eg, childbirth) and specific behaviors. Results are summarized below.

• Childbirth: Evidence linking an increasing risk of developing UI with the number of vaginal births is suggestive, but not consistent, across studies.⁴
  
• Obesity: May be a contributing factor to UI. However, weight loss appears to improve and even eliminate UI in obese women.⁴
• Constipation: Constipation associated with straining during defecation has been implicated as a contributory factor to an increased risk of UI; however, results are not consistent across studies.⁴
• Smoking: Current smoking status has been reported to be a risk factor for UI. Results for former smoker status, however, are inconsistent across studies.⁴
• Hysterectomy: Study results evaluating prior hysterectomy as a risk factor for UI have been inconsistent. However, a meta-analysis of 5 previously published studies indicated that women with a history of prior hysterectomy have a 60% greater risk of UI than women who had not had a hysterectomy.⁵
• Hormone therapy: Both oral exogenous estrogen therapy and combination estrogen/progestin therapy have been shown to increase the incidence of UI.⁶

 A paucity of data explores the relationship between modifying risk and preventing or reducing UI incidence. It is important to note, however, that behavioral modifications in the areas of smoking and obesity have positive health implications, for example in the cardiovascular area, that go well beyond benefits specific to UI.⁴

Beyond the potential benefits of risk-factor reduction, evidence supports interventions, such as pelvic floor muscle (PFM) training and bladder training behavioral modification programs, as preventing UI-related events in older women. The PFMs provide structural support to the pelvic organs and are part of the continence system. Women with UI have been reported to have differences in PFM function compared to normal women.⁷

When pharmacotherapy becomes the therapy of choice, it is best used in combination with behavioral modification techniques. Pharmacotherapeutic agents are available for the treatment of UUI, but pharmacotherapy for SUI is limited. Duloxetine, an investigational new drug, has demonstrated promising results for women of all ages with SUI.⁸

References

1. Holroyd-Leduc JM, Straus SE. Management of urinary incontinence in women. JAMA. 2004;291:986-995.

2. Brown JS, Grady D, Ouslander JG, Herzog AR, Varner RE, Posner SF, for the Heart & Estrogen/Progestin Replacement Study (HERS) Research Group. Prevalence of urinary incontinence and associated risk factors in postmenopausal women. Obstet Gynecol. 1999;94:66-70.

3. Diokno AC, Brock BM, Herzog AR, Bromberg J. Medical correlates of urinary incontinence in the elderly. Urology. 1990;36:129-138.

4. Engberg S. Age-associated risks and strategies for the prevention and management of stress urinary incontinence in community-dwelling older women. Womens Health Care. 2005;Feb(suppl):8-12.

5. Brown JS, Sawaya G, Thom DH, Grady D. Hysterectomy and urinary incontinence: a systematic review. Lancet. 2000;356:535-539.

6. Hendrix SL, Cochrane BB, Nygaard IE, et al. Effects of estrogen with and without progestin on urinary incontinence. JAMA. 2005;293:935-948.

7. Gunnarsson M, Mattiasson A. Female stress, urge, and mixed urinary incontinence are associated with a chronic and progressive pelvic floor/vaginal neuromuscular disorder: an investigation of 317 healthy and incontinent women using vaginal surface electromyography. Neurourol Urodyn. 1999;18:613-621.

8. Dmochowski RR, Miklos JR, Norton PA, Zinner NR, Yalcin I, Bump RC, for the Duloxetine Urinary Incontinence Study Group. Duloxetine versus placebo for the treatment of North American women with stress urinary incontinence. J Urol. 2003;170:1259-1263.