Nocturia in men less than 50 years of age may be associated with obstructive sleep apnea syndrome

OBJECTIVES To assess the prevalence of nocturia in association with other voiding symptoms in men with obstructive sleep apnea syndrome (OSAS). METHODS Seventy-three patients in whom OSAS was diagnosed at Gifu Red Cross Hospital during the period from October 2005 through April 2006 were assessed on the basis of the International Prostate Symptom Score (IPSS) and the Apnea-Hypopnea Index (AHI). Nocturia was defined as two or more voids per night. We classified patients by the presence versus absence of nocturia and by age (less than 50 years versus 50 years or more). Between-group differences in the AHI and IPSS were analyzed by Student's t test or the Mann-Whitney U test. RESULTS Nocturia was found in 30 patients with OSAS (41.1%). The AHI was higher in patients with nocturia than in those without nocturia (P < 0.01), especially in patients less than 50 years of age (P < 0.005). However, other voiding symptoms were not associated with nocturia in the OSAS patients younger than 50 years. CONCLUSIONS The prevalence of nocturia is high among patients with OSAS. Our results suggest that OSAS may have some relationship to nocturia without other voiding symptoms in men less than 50 years of age.