Quantitative association between nocturnal voiding frequency and objective sleep quality in the general elderly population: the HEIJO-KYO cohort.
OBJECTIVE
A significant association between nocturia and subjective sleep quality has previously been reported; however, the association between nocturia and objective sleep quality remains unclear. The purpose of this study was to evaluate the quantitative association between nocturnal voiding (NV) frequency and objective sleep quality in a large, general, elderly population.


METHODS
Nocturnal voiding frequency, objective sleep quality, and subjective sleep quality were measured among 1086 community-based elderly individuals using actigraphy and the Pittsburgh Sleep Quality Index (PSQI) questionnaire.


RESULTS
In multivariate analyses adjusted for potential confounding factors (such as age, gender, body mass index, medication use, renal function, bedtime, rising time, daytime physical activity, endogenous melatonin levels, and bedroom light levels), increased NV frequency, ranging from zero, one, two, three or more voids, was significantly associated with poorer objective sleep quality, including lower sleep efficiency (SE) and longer wake after sleep onset (WASO) (mean SE, 86.3, 84.8, 83.6, and 81.2%, respectively; p for trend <0.001; mean WASO: 42.6, 49.0, 53.6, and 66.1 min, respectively; p for trend <0.001), but shorter sleep onset latency (SOL) (mean SOL, 3.0, 3.0, 2.8, and 2.8 log min, respectively; p for trend = 0.018). In addition, an increased NV frequency was significantly associated with poorer subjective sleep quality in a multivariate model (mean PSQI global score, 4.60, 4.86, 5.22, and 5.48, respectively; p for trend 0.012).


CONCLUSIONS
The present study revealed a quantitative association between NV frequency and objective sleep quality in the general elderly population.
Department of Community Health and Epidemiology, Nara Medical University School of Medicine, Nara, Japan. Electronic address: obayashi@naramed-u.ac.jp.
Kenji
K
Obayashi
Department of Community Health and Epidemiology, Nara Medical University School of Medicine, Nara, Japan.
Keigo
K
Saeki
Department of Community Health and Epidemiology, Nara Medical University School of Medicine, Nara, Japan.
Norio
N
Kurumatani
D056044:Actigraphy; D000367:Age Factors; D000368:Aged; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D053158:Nocturia / Q000150:complications* / Q000453:epidemiology; D012307:Risk Factors; D012737:Sex Factors; D012890:Sleep; D012892:Sleep Deprivation / Q000453:epidemiology / Q000209:etiology*; D011795:Surveys and Questionnaires
Actigraphy; Melatonin; Nocturia; Nocturnal voiding frequency; Sleep quality