Objectives
Insomnia, especially difficulty maintaining sleep, is prevalent among older adults and increases the incidence of falls and fractures. Moreover, the drugs used to treat it exacerbate the risk. Yet current therapies fail to address one of its most common causes in older adults: nocturia and its primary contributor, nocturnal polyuria (NP), especially among the majority of individuals without lower urinary tract symptoms (LUTS). Therefore, we examined the factors associated with nocturia in two groups of such older women and the impact of nocturia on sleep.
Design
Secondary analysis of two observational studies of bladder function in carefully evaluated healthy older women.
Setting
Academic medical center.
Participants
A total of 39 women without LUTS who had adequate fluid intake (ie, >1200 mL urine output/24 h recorded on their diary), normal videourodynamic testing, and normal daytime frequency (≤7 voids).
Measurements
Voided volumes and sleep duration obtained from subjects’ 3‐day voiding diary, and sleep quality from the Center for Epidemiologic Studies Depression Scale. Nighttime excretion of more than 33% of 24‐hour urine volume was considered NP.
Results
Overall, 21 of these healthy subjects (54%) awakened at least once nightly to void, and 19 (90%) of them had NP. Compared with those without nocturia, participants with nocturia had shorter duration of the first uninterrupted sleep period (182 ± 100 vs 250 ± 60 min; P = .03), and they reported worse sleep quality. Two factors contributed independently to nocturia: (1) a larger proportion of 24‐hour urine output at night (43.4 ± 7.4% vs 25.4 ± 5.5%; P = <.001) and (2) smaller bladder capacity (484 ± 157 mL vs 608 ± 167 mL; P = .02).
Conclusions
Nocturia, NP, and reduced bladder capacity are very common even in healthy older women without LUTS and are associated with impaired sleep. Thus applying currently available modalities to address both NP and reduced bladder capacity may effectively treat sleep disruption without incurring the complications of sedative‐hypnotics.
By Prof. van Kerrebroeck
The authors state as an introduction that insomnia, especially difficulty maintaining sleep, is prevalent among older adults, increases the incidence of falls and fractures, and drugs used to treat insomnia exacerbate the risk. Furthermore they quite correctly state that current therapies fail to address one of the most common causes of insomnia in older adults, being nocturia and its primary contributor, nocturnal polyuria (NP), especially among the majority of individuals without lower urinary tract symptoms (LUTS). Therefore, they examined the factors associated with nocturia in two groups of such older women.
A secondary analysis was performed of two observational studies on bladder function in carefully evaluated healthy older women in an academic medical centre.
A total of 39 women without LUTS were studied who had adequate fluid intake (ie, >1200 mL urine output/24 h recorded on their diary), normal video-urodynamic testing, and normal daytime frequency (≤7 voids). Voided volumes and sleep duration were obtained from subjects based on a 3-day voiding diary, and sleep quality from the Center for Epidemiologic Studies Depression Scale. Nighttime excretion of more than 33% of 24-hour urine volume was considered NP.
Overall, 21 of these healthy subjects (54%) awakened at least once nightly to void, and 19 (90%) of them had NP. Compared with those without nocturia, participants with nocturia had shorter duration of the first uninterrupted sleep period (182 ± 100 vs 250 ± 60 min; P = .03), and they reported worse sleep quality. Two factors contributed independently to nocturia: (1) a larger proportion of 24-hour urine output at night (43.4 ± 7.4% vs 25.4 ± 5.5%; P = <.001) and (2) smaller bladder capacity (484 ± 157 mL vs 608 ± 167 mL; P = .02).
Based on these results the authors conclude that nocturia, NP, and reduced bladder capacity are very common even in healthy older women without LUTS and are associated with impaired sleep. They advocate that applying currently available modalities to address both NP and reduced bladder capacity may effectively treat sleep disruption without incurring the complications of sedative-hypnotics.
By Prof. van Kerrebroeck
Any medical doctor confronted with patients with insomnia should consider nocturia as an important contributing factor and pay attention to the pathophysiological factors causing the nocturnal voids.