A systematic review of overweight and obesity as risk factors and targets for clinical intervention for urinary incontinence in women.

AIMS To review the epidemiological literature of urinary incontinence with respect to overweight and obesity as a risk factor, and how the findings eventually fulfill general criteria for being a causal factor for the condition. Likewise to review all interventional studies assessing the effect of weight reduction on incontinence. METHODS Systematic searches until June 2008 for publications of community based prevalence studies with bivariate or multivariate analyses of the association between urinary incontinence in women and overweigh/obesity. In addition an attempt was made to identity and assess all relevant longitudinal studies, prospective case series, and trials, whatever design. RESULTS There is evidence 3 and some evidence 2 level data to support that in addition to BMI, waist-hip ratio and thus abdominal obesity may be an independent risk factor for incontinence in women. Only a few interventional studies have been carried out to assess the effect of weight reduction on incontinence. Five studies report effect on incontinence after surgical weight reduction procedures, and one study after a weight reduction program, thus giving some level 2 documentation. There are three RCTs which all show reducing incontinence by weight loss (level of evidence 1). CONCLUSIONS Epidemiological studies document overweight and obesity as an important risk factor for urinary incontinence. There is now valid documentation for weight reduction as a treatment for urinary incontinence in women.