Impact of Nocturia on Mortality: The Nagahama Study.

Nocturia has been reported as a risk factor for mortality; however, evidence is limited and has a high risk of bias. We evaluated the association between nocturia and mortality using longitudinal data from the general Japanese population.

Data were obtained from the Nagahama Cohort Project, a longitudinal, general population cohort study. Nocturia was measured using the International Prostate Symptom Score. Mortality data were obtained from the Basic Resident Register in Nagahama City. We used Cox proportional hazard models and time-varying covariates at baseline and 5-year follow-up to analyze the association between nocturia and mortality.

We analyzed 9,762 participants (median age, 56.8 years; male, 32.8%). The prevalence rates of nocturnal voiding at 0, 1, 2, and ≥3 times were 44.3%, 39.1%, 11.7%, and 4.9%, respectively. A total 263 participants died; the follow-up assessment was performed 3,224 (standard deviation [SD], 537) days after baseline. According to multivariable Cox proportional hazard regressions, mortality increased dose-dependently with the nocturnal voiding frequency as follows: hazard ratio (HR) of 1.46 for 1 time (95% confidence interval [CI], 1.02-2.09); HR of 1.85 for 2 times (95% CI, 1.23-2.77); and HR of 2.06 (95% CI, 1.28-3.32) for ≥3 times in comparison with 0 times (P for trend = 0.00084). In the time-varying Cox proportional hazard regression, the association was still significant (P for trend = 0.0017).

According to this longitudinal study with a low incidence of missing data and high representation of the general population, nocturia is associated with mortality.

The Journal of urology. 2020 May 12 [Epub ahead of print]

Satoshi Funada, Yasuharu Tabara, Kazuya Setoh, Hiromitsu Negoro, Shusuke Akamatsu, Takayuki Yoshino, Koji Yoshimura, Norio Watanabe, Toshi A Furukawa, Fumihiko Matsuda, Osamu Ogawa

Department of Urology, Kyoto University Graduate School of Medicine, Kyoto, Japan., Center for Genomic Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan., Department of Urology, University of Tsukuba Hospital, Ibaraki, Japan., Department of Urology, Shizuoka General Hospital, Shizuoka, Japan., Department of Health Promotion and Human Behavior, Kyoto University School of Public Health, Kyoto, Japan.