Mortality in older men with nocturia. A 15-year followup of the Krimpen study.

PURPOSE: Although nocturia seems to be related to increased mortality in older men, it is unclear whether this is an independent association. Therefore, we studied the association of nocturia and mortality in community dwelling older men. MATERIALS AND METHODS: A longitudinal, population based study was conducted among 1,688 men 50 to 78 years old. Recruitment started in 1995. At baseline all men completed a questionnaire and a 3-day frequency-volume chart. Nocturnal voiding frequency was derived from the frequency-volume chart and nocturia was defined as 2 or more voids per night. In 2010 all general practitioners' patient records were checked for possible date of death. Univariable and multivariable Cox regression analyses were performed. A subanalysis was performed to determine the effect of 3 longitudinal nocturia patterns (ie incident, persistent or transient/resolved) on the mortality rate. RESULTS: A total of 1,114 men were eligible for analysis. Median followup was 13.4 years (quartiles 1 to 3: 10.3-14.1) for a total of 12,790 person-years of followup. Univariably nocturia was associated with an increased mortality rate (HR 1.63, 95% CI 1.20-2.21, p = 0.002). After correction for possible confounding factors nocturia had no significant influence on mortality (p = 0.838) in contrast to age, chronic obstructive pulmonary disease, smoking and hypertension (all p <0.05). Men with persistent nocturia had the highest mortality rate compared to those without nocturia. However, this association was not significant (p = 0.083). CONCLUSIONS: In an analysis based on frequency-volume chart data, the association between nocturia and mortality was explained by confounding factors, predominantly age. Furthermore, the mortality risk was not associated with the 3 nocturia patterns.