Nocturia is commonly associated with prostate or bladder problems but is also an important symptom of obstructive sleep apnea, a potentially lethal condition. The primary purpose of this study was to test the relationship between symptoms of sleep-disordered breathing and increased nocturnal urine production as described by the Sleep-Disordered Breathing--Nocturia Model. The purpose of the first phase of this three-phase study was to survey community-dwelling older adults (> 55 years) about nocturia and sleep-disturbance symptoms. A random sample of 1,000 older adults, balanced by ethnicity and gender, were surveyed via a mailed questionnaire. The brief questionnaire included characterizing poor sleep quality, obstructive sleep apnea symptoms, nocturia, lower urinary tract symptoms, naps, and self-rated health. The return rate was low (18%, n = 176), but respondents were equally represented by gender and ethnicity across the targeted age groups. Half of the respondents (n = 87) reported > or = 2 voids per night, two-thirds of whom reported nocturia as bothersome. The data showed that African-American women had significant associations between episodes of nocturia and symptoms of obstructive sleep apnea, poor sleep quality, naps, and lower urinary tract symptoms, thus failing to support the notion that nocturia or sleep-disordered breathing are prostate or gender related. As expected, subjects (n = 80) who volunteered for the later phases of the study, had significantly more problems. These preliminary data suggest that the relationship between obstructive sleep apnea and nocturia is important because older adults are at higher risk of injury due to falls that may occur while attempting to toilet in the dark. Also, older adults may also be at higher risk of receiving inappropriate urologic treatment if they are not screened for sleep disorders when reporting nocturia along with symptoms of excessive daytime sleepiness and sleep-disordered breathing. Phases II and III of the parent study will include a detailed examination of hormonal, biochemical, and physical variables to further test the proposed Sleep-Disordered Breathing--Nocturia Model.