Evaluation of Patients with Nocturia by Age Using a Bladder Diary: A Multi-Institutional Study

Iinuma K1, Nishino Y2, Matsuoka K3, Ihara T4, Makabe S5, Tanji R6, Harigane Y7, Ishida K8, Tamaki M9, Yokoi S10, Hoshino H11, Yuhara K12, Yamada T13, Miwa K14, Hagiwara N15, Kikuchi M16, Kojima Y3, Mitsui T17, Koie T1

Research Type

Clinical

Abstract Category

Nocturia

Abstract 269
Urology 9 - Nocturia: from Basics to Clinics
Scientific Podium Short Oral Session 23
Saturday 20th September 2025
11:30 - 11:37
Parallel Hall 2
Nocturia Voiding Diary Male Female
1. Department of Urology, Graduate School of Medicine, Gifu University, 2. Nishino Clinic, 3. Department of Urology, Fukushima Medical University, 4. Department of Urology, Toranomon Hospital Kajigaya, 5. Department of Urology, Ohara General Hospital, 6. Department of Urology, Japanese Red Cross Fukushima Hospital, 7. Department of Urology, Ohta Nishinouchi Hospital, 8. Matsunami General Hospital, 9. Department of Urology, Gifu Municipal Hospital, 10. Department of Urology, Central Japan International Medical Center, 11. Department of Urology, Toyota Memorial Hospital, 12. Department of Urology, Japanese Red Cross Takayama Hospital, 13. Department of Urology, Tokai Central Hospital, 14. Department of Urology, Japanese Red Cross Gifu Hospital, 15. Department of Urology, Matsunami General Hospital, 16. Sugo Clinic, 17. Department of Urology, University of Yamanashi Graduate School of Medical Sciences
Presenter
Links

Abstract

Hypothesis / aims of study
Nocturia, defined as the symptoms of waking up more than once during the night to urinate, negatively impacts quality of life and increases the risks of sleep disorders, depression, and metabolic syndrome. In elderly patients, it has also been associated with falls and fractures. With the aging population, nocturia has become a very important symptom. This condition is primarily caused by nocturnal polyuria (NP), bladder storage dysfunction, and sleep disorders, with cardiovascular disease also being a contributing factor. Our previous study reported that NP was present in 67.4% of 875 patients with nocturia and that its prevalence increased with age (1). However, limited data exist regarding age-related differences in patient characteristics and urination patterns. This study aimed to analyze characteristics of patients with nocturia and urination patterns using a bladder diary across different age groups.
Study design, materials and methods
This study was approved by the Institutional Review Board (approval number: 2021-053). In this multi-institutional observation study, patients presenting with nocturia as their main complaint at 17 institutions in Japan from January 2018 to December 2022 were enrolled. Patients were categorized into five age groups: <50, 50–59, 60–69, 70–79, and ≥80 years. Urinary frequency and voiding volume were assessed using a bladder diary. The primary endpoint was NP index variation with age. Secondary endpoints included characteristics of patients with nocturia, 24-hour, daytime, and nighttime voided volumes, and maximum voided volume, all categorized by age. The Steel-Dwass test was used for age-group comparisons, with statistical significance set at p < 0.05.
Results
In this study, 875 patients were included in the analysis and divided into five groups by age. The characteristic data of the enrolled patients are listed in Table 1. The median NP index, which was the primary endpoint, in patients <50 years, 50–59 years, 60–69 years, 70–79 years, and ≥80 years were 28.0%, 34.0%, 34.0%, 38.5%, and 42.0%, respectively (Fig. 1a). In patients ≥80 years, the NP index was significantly higher compared to other age groups (p < 0.05, Fig. 1a). In patients ≥80 years, the 24-hour and daytime voided volume were significantly lower compared to patients 50–59, 60–69, and 70–79 years (p < 0.05, Fig. 1b, 1c). Conversely, the nighttime voided volume was significantly higher in patients ≥80 years and 70–79 years compared to patients <50 years (p < 0.05, Fig 1d). The maximum voided volume was significantly lower in patients ≥80 years compared to those in patients with 50–59 years, 60–69 years, and 70-79 years (p < 0.05, Fig.1e).
Interpretation of results
In this study, it was shown that the NP index increases with age. Interestingly, in patients with ≥80 years, the 24-hour and daytime voided volume were significantly lower compared to other age groups, while the nighttime voided volume was significantly higher compared to patients <50 years. This leads to a rise in the NP index, which may contribute to NP and subsequently nocturia. Additionally, it is suggested that the decrease in bladder capacity with aging may also contribute to the development of nocturia.
Concluding message
To the best of our knowledge, this is the largest multi-institutional study to investigate the patient characteristics and urination patterns using bladder diary by age in Japanese patients with nocturia. In patients with nocturia, elderly patients tend to have a higher NP index and smaller bladder capacity compared to younger patients. Therefore, in elderly patients, in addition to administering medications that reduce nighttime voided volume such as desmopressin, the combination with anticholinergics or β-3 adrenoceptor agonist may be effective.
Figure 1
Figure 2
References
  1. Iinuma K, Nishino Y, Matsuoka K, et al. The prevalence and predictive factors of nocturnal polyuria in Japanese patients with nocturia: a multicentral retrospective cohort study. Sci Rep, 2023.
Disclosures
Funding None. Clinical Trial Yes Public Registry No RCT No Subjects Human Ethics Committee Institutional Review Board of Gifu University Helsinki Yes Informed Consent Yes
04/07/2025 06:03:11