Abstract
INTRODUCTION AND HYPOTHESIS: The aim of the present study was in a case-control design to evaluate the association between nocturia and obstructive sleep apnea, in men and women who had nocturia ≥ 2 per night (nocturics) compared to those without nocturia (controls). METHODS: Participants were randomly selected among respondents in a population study of 4000 elderly individuals. Nocturia was assessed using the validated Nocturia, Nocturnal Enuresis, and Sleep-interruption Questionnaire (NNES-Q). Nocturia (≥ 2 voids/night) or control (< 1 void/night) status was assessed by a 3-day frequency volume chart (FVC). Furthermore, all participants completed an overnight ambulatory polygraphic recording to identify obstructive sleep apnea (OSA). RESULTS: Of 1111 eligible individuals, a total of 75 nocturics and 75 controls (13.5%) were included. Overall, the prevalence and severity of OSA among nocturics and controls was not significantly different. In a sub-analysis we found that 22 nocturics with OSA (69%) had nocturnal polyuria. This led to a significantly increased risk of having OSA (OR 2.8, 95% CI: 1.1-7.3, p < 0.05) when having nocturnal polyuria compared to other pathophysiological causes of nocturia (polyuria, low bladder capacity, a combination of nocturnal polyuria/low bladder capacity, and neither nocturnal polyuria/low bladder capacity). CONCLUSIONS: Nocturia twice or more was not significantly associated with OSA. However, nocturics with nocturnal polyuria had a significantly higher risk of having OSA than nocturics with other pathophysiologies.