By Chiara Ghetti, MD

Associate Professor, Obstetrics and Gynecology, Division of Female Pelvic Medicine and Reconstructive Surgery, Washington University School of Medicine, St. Louis

Dr. Ghetti reports no financial relationships relevant to this field of study.

SYNOPSIS: Weight loss interventions were associated with improvements in urinary incontinence in overweight and obese women at one to 2.9 years.

SOURCE: Yazdany T, Jakus-Waldman S, Jeppson PC, et al. American Urogynecologic Society Systematic Review: The impact of weight loss intervention on lower urinary tract symptoms and urinary incontinence in overweight and obese women. Female Pelvic Med Reconstr Surg 2020;26:16-29.

The main objective of this study was to evaluate existing data on how weight loss interventions (behavioral and surgical) affect lower urinary tract symptoms in overweight and obese women. This systematic review was conducted by the American Urogynecologic Society Systematic Review Group and registered at Prospero.

Researchers searched PubMed, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), and the Cochrane Library for English-language articles from Jan. 1, 1990, to Dec. 1, 2018. Full-text articles were selected based on set inclusion and exclusion criteria. Eligible studies included randomized, controlled trials and cohort and case-control investigations. Case series were included only if pre- and post-intervention outcomes were reported. Studies included women age 18 years whose mean body mass index (BMI) was ≥ 30 kg/m2 enrolled in behavioral or surgical weight loss programs and with symptoms of urinary incontinence or overactive bladder. Behavioral weight loss interventions included diet modification, exercise programs, medications, and/or counseling. Review articles were excluded, as were studies of subjects with interstitial cystitis, bladder pain syndrome, fistulas, pelvic cancer, urinary retention, neurogenic bladder, spinal cord injury, or subjects who had undergone pelvic irradiation or were pregnant. Only data pertaining to women were included in the reported study.

Evidence for certainty of outcomes was categorized using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) and was rated as high, moderate, low, and very low certainty. A grade of high certainty meant the authors were confident the real outcome or true effect comes close to the estimated, while very low certainty evidence meant the authors were not confident at all in the estimate, and that the real effect was likely to be significantly different from the estimate. The authors found high-certainty evidence that behavioral weight loss (diet and exercise) leads to moderate reduction in the prevalence of stress urinary incontinence and overall urinary incontinence (12% to 18%, collectively). However, there was low-certainty evidence on the long-term effects of behavioral weight loss interventions, and only moderate to low certainty evidence exists regarding the effects of weight loss on urge incontinence and overactive bladder symptoms. To date, there is little evidence about the effect of surgical weight loss on urinary symptoms, and there are no randomized studies.

COMMENTARY

Urinary incontinence affects nearly half of all women.1 Obesity is a strong independent risk factor for the condition.2 Obesity is a growing public health problem worldwide, with a prevalence of 42.4% in the United States in 2017-2018.3 Epidemiologic studies indicate a 20% to 70% increase in the risk of incontinence with each five unit increase in BMI. Prior studies have shown improvements in urinary incontinence symptoms with weight loss. The goal of this study was to evaluate the existing evidence supporting weight loss for the treatment of urinary incontinence to aid in treatment recommendations. The authors found strong evidence to support improvement of urinary incontinence in the short term following behavioral weight loss. However, it appears weight loss benefits may diminish over time. In light of this evidence, the authors suggested providers not delay treatment of incontinence in women not interested in weight loss.

The treatment of urinary incontinence often is multimodal and certainly should not be delayed. However, the relationship between obesity and urinary incontinence treatment is not simple, either. In a retrospective cohort study of 431 subjects undergoing midurethral sling, Elshatanoufy et al found that patients with class 3 obesity (BMI 40 kg/m2) were twice as likely to fail treatment and had either postoperative stress urinary incontinence symptoms or required additional treatment for stress urinary incontinence.4 In another recent study of the British Society of Urogynaecology database of 11,859 women treated with midurethral sling, Bach et al found patient-reported subjective urinary incontinence symptoms, measured by validated measures, worsened as BMI increased.5

An earlier systematic review and meta-analysis by Greer et al suggested midurethral sling cure rates were lower in obese women.6 There are significant knowledge gaps in both understanding the long-term effects of weight loss and the effects of surgical weight loss in the treatment of urinary incontinence. More studies also are needed to better understand the long-term effectiveness of surgical interventions for urinary incontinence in obese patients.

In pondering these relationships between obesity, weight loss, and incontinence, we must acknowledge obesity is the second most common cause of preventable death. Each five-unit increase in BMI confers approximately 30% higher overall mortality.7,8 Obesity increases the risk of cancer, hypertension, heart disease, diabetes, stroke, sleep apnea, and musculoskeletal disorders. As providers addressing the quality of life burden of urinary incontinence, it is imperative we counsel our patients extensively about the risks of obesity while building a therapeutic partnership to promote changes that will lead to weight loss. Although weight loss may not provide long-term urinary symptom reduction, the consequences of persistent obesity are formidable.

REFERENCES

  1. Sampselle CM, Harlow SD, Skurnick J, et al. Urinary incontinence predictors and life impact in ethnically diverse perimenopausal women. Obstet Gynecol 2002;100:1230-1238.
  2. Subak LL, Richter HE, Hunskaar S. Obesity and urinary incontinence: Epidemiology and clinical research update. J Urol 2009;182:S2-S7.2.
  3. Centers for Disease Control and Prevention. Prevalence of obesity and severe obesity among adults: United States, 2017-2018. Published February 2020.
  4. Elshatanoufy S, Matthews A, Yousif M, et al. Effect of morbid obesity on midurethral sling efficacy for the management of stress urinary incontinence. Female Pelvic Med Reconstr Surg 2019;25:448-452.
  5. Bach F, Hill S, Toozs-Hobson P. The effect of body mass index on retropubic midurethral slings. Am J Obstet Gynecol 2019;220:371.e1-371.e9.
  6. Greer WJ, Richter HE, Bartolucci AA, Burgio KL. Obesity and pelvic floor disorders: A systematic review. Obstet Gynecol 2008;112:341-349.
  7. Flegal KM, Graubard BI, Williamson DF, Gail MH. Excess deaths associated with underweight, overweight, and obesity. JAMA 2005;293:1861-1867.
  8. Prospective Studies Collaboration, Whitlock G, Lewington S, et al. Body-mass index and cause-specific mortality in 900 000 adults: Collaborative analyses of 57 prospective studies. Lancet 2009;373:1083-1096.