To investigate urination parameters measured by toilet uroflowmetry in hospitalized men with nocturia over a 24-hour period to clarify the circadian rhythm of urination. Physicians often encounter male patients with complaints of low maximum flow rate only in the early morning. However, this has not been proved scientifically because most urinary examinations are generally performed for outpatients only during the daytime.
This retrospective study included 117 hospitalized male patients (age, 68.7 ± 12.8 years). The data of 4689 urinations during their hospital stay were evaluated on the ward by toilet uroflowmetry, which is a toilet-type device that allows patients to urinate as usual. The records including voided volume, maximum flow rate, and voiding time were evaluated as averages of eight time periods of three hours each by generalized linear mixed models with an identity link function to adjust for personal bias.
Voided volume after adjustment for age was significantly higher during the nighttime (21:00-06:00) than that in the morning (06:00-09:00) and highest from 00:00-03:00. Interestingly, even after adjustment for both voided volume and age, the maximum flow rate from 06:00-09:00 was the lowest. Voiding time after adjustment for age and voided volume was significantly higher during the nighttime (00:00-06:00) than that from 06:00-09:00.
We clearly showed the circadian rhythm of urination in a group of hospitalized men with nocturia. Maximum flow rate was lowest in the early morning, including just after waking up.
Urology. 2022 Mar 18 [Epub ahead of print]
Ippei Hiramatsu, Akira Tsujimura, Miho Miyoshi, Taiki Ogasa, Yuto Miyoshi, Keisuke Ishikawa, Yuka Uesaka, Taiji Nozaki, Masato Shirai, Hiroshi Kiuchi, Shigeo Horie
Department of Urology, Juntendo University, Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan; Department of Urology, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu, Chiba 279-0021, Japan., Department of Urology, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu, Chiba 279-0021, Japan. Electronic address: ., Department of Urology, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu, Chiba 279-0021, Japan., Osaka University Graduate School of Medicine Department of Urology, 1-1 Yamadaoka, Suita, Osaka 565-0871, Japan., Department of Urology, Juntendo University, Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.