Prevalence and Correlates of Nocturia in Community-dwelling Older Men: Results from the Korean Longitudinal Study on Health and Aging

PURPOSE To determine the prevalence and correlates of nocturia in Korean community-dwelling older men. MATERIALS AND METHODS A study population of 439 Korean elderly men (≥65 years of age, including 299 men from a randomly sampled population) was sampled from residents of Seongnam, Korea. Standardized face-to-face interviews and questionnaires were performed. In-person interviews solicited sociodemographic information, medical history, Mini-Mental State Examination (MMSE) score, and measurement of body mass index. Transrectal ultrasonography and laboratory tests including urinalysis and measurement of creatinine and prostate-specific antigen were performed. For the analysis of prevalence, 299 randomly sampled men were included. Men who answered the International Prostate Symptom Score questionnaire (n=424) were included in the analysis of the correlates of nocturia. Nocturia was defined as having to get up to urinate two or more times per night (≥2). RESULTS The overall prevalence of nocturia was 56.0% for community-dwelling older men. There was a significant correlation between age and the prevalence of nocturia (p<0.001). The univariate analysis revealed a significant association between nocturia and MMSE score (odds ratio [OR], 0.88; p<0.001), history of benign prostatic hyperplasia (BPH) (OR, 2.85; p=0.003), alpha-blocker usage (OR, 2.79; p=0.018), alcohol consumption (OR, 0.65; p=0.035), and smoking (OR, 0.58; p=0.025). Age, duration of education, MMSE score, and prostate volume were also significantly associated with nocturia. In the multivariate regression analysis using forward elimination, nocturia was significantly associated with a history of BPH and MMSE score. CONCLUSIONS The prevalence of nocturia was 56.0% in Korean community-dwelling older men. Nocturia was associated with age and a history of BPH. MMSE score was protective.