BMI, waist circumferences and urinary incontinence in older women compared with older men: findings from three prospective longitudinal cohort studies

Abstract

Abstract Background Obesity and urinary incontinence (UI) among older people, particularly older men, are yet to be fully explored. Utilising multiple nationwide prospective longitudinal cohorts representative of the US, UK, and European samples, we examined the association of body mass index (BMI) and waist circumference (WC) with UI among both older women and men. Methods We derived the data from the Health and Retirement Study (HRS, 2010-2018), the English Longitudinal Study of Aging (ELSA, 2011-2019), and the Survey of Health, Ageing and Retirement in Europe (SHARE, 2004-2010) that surveyed UI. Participants were asked if they had experienced urine leakage within the past 12 months (HRS and ELSA) or within the past six months (SHARE). The measure of obesity was based on BMI and WC. We employed a random-effect logistic model to associate BMI and WC with UI, adjusting for covariates including age, race, education, residence area, marital status, number of children, smoking, drinking, hypertension, diabetes, cancer, stroke, functional ability, and cognitive impairment. We visualised the associations by using restricted cubic spline curves. Findings A total of 200,717 participants with 718,822 observations (207,805 in HRS; 98,158 in ELSA; 412,859 in SHARE) were included in the baseline analysis. The 12-months prevalence of UI among female and male participants were 15.6% and 6.6% in the HRS, 10.6% and 4.4% in the ELSA. The 6-months prevalence of UI were 2.8% and 1.4% in the SHARE’s female and male participants. Compared to those without UI, both female and male participants with UI demonstrated a higher BMI and WC. Among females, the fully adjusted models showed linear associations between BMI, WC, and UI (Ps<0.001) in three cohorts. However, we observed U-shaped associations of BMI, WC with UI among males. The lowest likelihood of having UI was found among male participants with a BMI between 24 and 35 kg/m2. Interpretation Findings from our study revealed that the associations of obesity indices with UI varied among older men compared to older women. As a result, weight loss interventions could be applied to older women rather than older men as a means of treating UI. Interventions aimed at preventing UI among older adults must take sex into account.