Background: Adiposity has been associated with elevated risk of urinary incontinence in epidemiological studies; however, the strength of the association has differed between studies.
Objectives: To conduct a systematic literature review and dose-response meta-analysis of prospective studies on adiposity and risk of urinary incontinence.
Search strategy: We searched PubMed and Embase databases up to 19 July 2017.
Selection criteria: Prospective cohort studies were included.
Data collection and analysis: Data were extracted by one reviewer and checked for accuracy by a second reviewer. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random effects models.
Main results: Twenty-four prospective studies were included. The summary RR per 5 kg/m2 increment in body mass index (BMI) was 1.20 (95% CI 1.16-1.25, I2 = 62%, n = 11) for population-based studies and 1.19 (95% CI 1.08-1.30, I2 = 87.1%, n = 8) for pregnancy-based studies, 1.18 (95% CI 1.14-1.22, I2 = 0%, n = 2) per 10 cm increase in waist circumference and 1.34 (95% CI 1.11-1.62, I2 = 90%, n = 2) per 10 kg of weight gain. Although the test for nonlinearity was significant for BMI, P = 0.04, the association was approximately linear. For subtypes of urinary incontinence the summary RR per 5 BMI units was 1.45 (95% CI 1.25-1.68, I2 = 85%, n = 3) for frequent incontinence, 1.52 (95% CI 1.37-1.68, I2 = 34%, n = 4) for severe incontinence, 1.33 (95% CI 1.26-1.41, I2 = 0%, n = 8) for stress incontinence, 1.26 (95% CI 1.14-1.40, I2 = 70%, n = 7) for urge incontinence, and 1.52 (95% CI 1.36-1.69, I2 = 0%, n = 3) for mixed incontinence.
Conclusion: These results suggest excess weight may increase risk of urinary incontinence.
Tweetable abstract: Overweight and obesity increase the risk of urinary incontinence.
Keywords: Body mass index; meta-analysis; obesity; overweight; prospective studies; urinary incontinence; waist circumference.
© 2019 Royal College of Obstetricians and Gynaecologists.