Sleep Apnea and Circadian Extracellular Fluid Change as Independent Factors for Nocturnal Polyuria.
OBJECTIVE
We investigated the relationships among nocturnal polyuria, sleep apnea and body fluid volume to elucidate the pathophysiology of nocturia in sleep apnea syndrome.


METHODS
We enrolled 104 consecutive patients who underwent polysomnography for suspected sleep apnea syndrome. Self-assessed symptom questionnaires were administered to evaluate sleep disorder and lower urinary tract symptoms, including nocturia. Voiding frequency and voided volume were recorded using a 24-hour frequency-volume chart. Body fluid composition was estimated in the morning and at night using bioelectric impedance analysis. Frequency-volume chart data were analyzed in 22 patients after continuous positive airway pressure therapy.


RESULTS
Patients with nocturnal polyuria showed a higher apnea-hypopnea index (33.9 vs 24.2, p = 0.03) and a larger circadian change in extracellular fluid adjusted to lean body mass (0.22 vs -0.19, p = 0.019) than those without nocturnal polyuria. These relations were more evident in patients 65 years old or older than in those 64 years or younger. A multivariate linear regression model showed an independent relationship of nocturnal polyuria with the apnea-hypopnea index and the circadian change in extracellular fluid adjusted to lean body mass (p = 0.0012 and 0.022, respectively). Continuous positive airway pressure therapy significantly improved nocturnal polyuria and nocturia only in patients with nocturnal polyuria.


CONCLUSIONS
This study identified sleep apnea and the circadian change in extracellular fluid as independent factors for nocturnal polyuria.
Department of Urology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
Aya
A
Niimi
Department of Urology, Tokyo Teishin Hospital, Tokyo, Japan.
Motofumi
M
Suzuki
Department of Geriatric Medicine, Graduate School of Medicine, University of Tokyo, Tokyo, Japan. Electronic address: yamayasu-tky@umin.ac.jp.
Yasuhiro
Y
Yamaguchi
Department of Geriatric Medicine, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
Masaki
M
Ishii
Department of Urology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
Tetsuya
T
Fujimura
Department of Urology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
Tohru
T
Nakagawa
Department of Urology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
Hiroshi
H
Fukuhara
Department of Urology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
Haruki
H
Kume
Department of Continence Medicine, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
Yasuhiko
Y
Igawa
Department of Geriatric Medicine, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
Masahiro
M
Akishita
Department of Urology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
Yukio
Y
Homma
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002940:Circadian Rhythm; D045604:Extracellular Fluid; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D053158:Nocturia / Q000209:etiology / Q000503:physiopathology*; D017286:Polysomnography; D011141:Polyuria / Q000209:etiology / Q000503:physiopathology*; D012891:Sleep Apnea Syndromes / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D011795:Surveys and Questionnaires
body fluids; circadian rhythm; polyuria; sleep apnea syndromes; urinary bladder