Association of nocturia and mortality: results from the Third National Health and Nutrition Examination Survey.

PURPOSE: Nocturia, a common problem in men and women, has been associated with chronic illnesses such as heart disease and hypertension. Using data from the Third National Health and Nutrition Examination Survey we investigated the association of nocturia with subsequent mortality risk. MATERIALS AND METHODS: NHANES III is a national probability survey of the United States between 1988 and 1994. Mortality data were obtained by linkage of NHANES III to the National Death Index. Cox proportional hazards regression models were used to assess the association between nocturia and all cause mortality, controlling for potential confounders in a sample of 15,988 men and women 20 years old or older. RESULTS: The prevalence of nocturia, defined as 2 or more voiding episodes nightly, was 15.5% in men and 20.9% in women. Multivariate analyses showed a statistically significant trend of increased mortality risk with increased number of voiding episodes in men and women. The magnitude of the nocturia and mortality association was greater in those younger than 65 years with attenuated associations in the 65 years old or older age group. CONCLUSIONS: Nocturia is a strong predictor of mortality, more so in younger men and women than in the elderly, with a dose-response pattern in increased mortality risk with increasing number of voiding episodes nightly. Potential underlying mechanisms of the observed association of nocturia and increased mortality risk include sleep disruption and subsequent development of related comorbid conditions.