Vitamin D and incident urinary incontinence in older adults.

BACKGROUND/OBJECTIVES: The aim of this study is to determine whether vitamin D status is associated with incident urinary incontinence (UI) among community-dwelling older adults.

SUBJECTS/METHODS: The University of Alabama at Birmingham Study of Aging is a prospective cohort study of community-dwelling Medicare enrollees. Standardized assessment of UI was conducted using the validated Incontinence Severity Index. The analysis of 25-hydroxyvitamin D [25(OH)D] levels was performed on stored baseline sera. UI was assessed every 6-12 months for up to 42 months. The analyses included multivariable logistic regression and Cox proportional hazard models.

RESULTS: Of 350 participants (175 male, 147 black, mean age 73.6±5.8), 54% (189/350) were vitamin D deficient (25(OH)D <20 ng/ml) and 25% (87/350) were vitamin D insufficient (25(OH)D: 20 ng/ml to <30 ng/ml). Among the 187 subjects with no UI at baseline, 57% (107/187) were vitamin D deficient and 24% (45/187) were vitamin D insufficient. A total of 175 of the 187 subjects had follow-up evaluation for incident UI over 42 months, and incident UI occurred in 37% (65/175). After adjustment, cumulative incident UI at 42 months was associated with baseline vitamin D insufficiency (P=0.03) and demonstrated a trend association with deficiency (P=0.07). There was no association between baseline vitamin D status and the time to incident UI.

CONCLUSIONS: These preliminary results support an association between vitamin D and incident UI in community-dwelling older adults. Future studies may target specific at-risk groups, such as men with BPH or women with pelvic floor disorders for evaluation of the impact of vitamin D supplementation on urinary symptoms.