Among younger men, lower body mass is associated with fewer urinary symptoms, including incontinence and nocturia. However, lower body mass may have different implications for older men due to age-associated muscle atrophy and decreased strength.

We conducted a prospective analysis of community-dwelling men, aged 70 to 79, in the multicenter Health, Aging, and Body Composition Study who underwent measurement of body mass (physical examination), composition (dual x-ray absorptiometry), and strength (grip and lower leg dynamometry). Associations with prevalent incontinence and nocturia (from structured questionnaires), as well as concurrent changes in urinary symptoms over 3 years was evaluated using multivariate logistic regression.

Of the 1,298 men analyzed, 22% reported incontinence and 52% reported nocturia at baseline. Higher body mass index and fat mass, as well as lower appendicular lean mass, grip and quadriceps strength (corrected for body mass index), were associated with increased prevalence of incontinence (P<0.05 for all). Higher body mass index and fat mass were also associated with increased nocturia prevalence (P<0.05 for all). Concurrent ≥5% decrease in body or fat mass was not associated with lower odds of new or worsening incontinence or nocturia, whereas ≥5% decrease in maximum grip strength was associated with higher odds of new or worsening incontinence.

Older men with higher body mass index and fat mass are more likely to report prevalent incontinence and nocturia. Whereas, late-life decreases in strength, but not increases in body or fat mass, were associated with concurrent increase in urinary incontinence.

The Journal of urology. 2019 Jun 12 [Epub ahead of print]

Scott R Bauer, Barbara Grimes, Anne M Suskind, Peggy M Cawthon, Steven Cummings, Alison J Huang, Health ABC Study

Department of Medicine, University of California , San Francisco , CA., Department of Epidemiology & Biostatistics, University of California , San Francisco , CA., Department of Urology, University of California , San Francisco , CA., Research Institute, California Pacific Medical Center , San Francisco , CA.