Letter to the Editor in Response to “Age and Nocturnal Polyuria in Nocturia: A Multicenter Voiding Diary Cohort Study”

Kawase et al.'s recent multicenter cohort study offers significant evidence about the relationship between nocturnal polyuria (NP) in nocturia patients and aging. The study shows that overactive bladder, maximal voided volume, and 24-h urine volume are significant predictors of NP and that both the nocturnal polyuria index and the prevalence of NP rise with age. Although these results significantly advance our knowledge of age-related urinary dysfunction, a number of methodological issues need to be addressed. The reported relationships may have been impacted by the retrospective design, reliance on self-reported voiding diaries, and lack of information on renal function, sleep problems, hydration status, and diuretic use. Furthermore, using a single diagnostic criteria for NP across all age groups might not accurately represent aging-related physiological changes. To better diagnose and treat nocturnal polyuria in older persons, future prospective studies that take these factors into account and assess age-specific diagnostic criteria are required.