Tag Archive for: cross-sectional analysis


Article of the Week: Indoor cold exposure and nocturia

Every Week the Editor-in-Chief selects an Article of the Week from the current issue of BJUI. The abstract is reproduced below and you can click on the button to read the full article, which is freely available to all readers for at least 30 days from the time of this post.

In addition to the article itself, there is an accompanying editorial written by a prominent member of the urological community. This blog is intended to provoke comment and discussion and we invite you to use the comment tools at the bottom of each post to join the conversation.

If you only have time to read one article this week, it should be this one.

Indoor cold exposure and nocturia: a cross-sectional analysis of the HEIJO-KYO study

Keigo Saeki, Kenji Obayashi and Norio Kurumatani
Department of Community Health and Epidemiology, Nara Medical University School of Medicine, Nara, Japan



To investigate the association between indoor cold exposure and the prevalence of nocturia in an elderly population.

Subjects and Methods

The temperature in the living rooms and bedrooms of 1 065 home-dwelling elderly volunteers (aged ≥60 years) was measured for 48 h. Nocturia (≥2 voids per night) and nocturnal urine production were determined using a urination diary and nocturnal urine collection, respectively.



The mean ± sd age of participants was 71.9 ± 7.1 years, and the prevalence of nocturia was 30.8%. A 1 °C decrease in daytime indoor temperature was associated with a higher odds ratio (OR) for nocturia (1.075, 95% confidence interval [CI] 1.026–1.126; P = 0.002), independently of outdoor temperature and other potential confounders such as basic characteristics (age, gender, body mass index, alcohol intake, smoking), comorbidities (diabetes, renal dysfunction), medications (calcium channel blocker, diuretics, sleeping pills), socio-economic status (education, household income), night-time dipping of ambulatory blood pressure, daytime physical activity, objectively measured sleep efficiency, and urinary 6-sulphatoxymelatonin excretion. The association remained significant after adjustment for nocturnal urine production rate (OR 1.095 [95% CI 1.042–1.150]; P < 0.001).


Indoor cold exposure during the daytime was independently associated with nocturia among elderly participants. The explanation for this association may be cold-induced detrusor overactivity. The prevalence of nocturia could be reduced by modification of the indoor thermal environment.

Editorial: Does cold exposure cause nocturia?

We have all experienced that changing from a warm environment to a colder external temperature may provoke a sudden compelling desire to void. This feeling fits quite well with part of the definition of urgency following the International Continence Society definition. Consequently, it is logical to suspect that cold exposure during daytime may influence bladder behaviour and hence contribute to nocturia episodes. These Japanese authors [1] performed a cross-sectional analysis as part of a community based cohort study in 1127 home-dwelling volunteers aged ≤60 years. Living room and bedroom temperatures were measured for 48 h and the participants completed voiding charts and nocturnal urine collection, but were excluded if >12 h were spent outside their house. The mean age of the participants was ≈72 years and nocturia was present in 30.8%. A decrease in daytime indoor temperature of 1 °C was associated with a higher odds ratio for nocturia and this was independent of outdoor temperature and other potential confounders. Furthermore, the association was independent of nocturnal urine production and hence reflect a direct effect on bladder behaviour, probably due to detrusor overactivity. However, a change of indoor temperature modified nocturia in only 29.3% of participants, and varied significantly in individuals. Nevertheless, these findings could be used as a population approach to reduce the prevalence of nocturia and hence the eventual impact on quality of life and morbidity that is known to go together with nocturia.

Philip Van Kerrebroeck, Professor of Urology
Department of Urology, Maastricht University Medical Centre, Maastricht, The Netherlands


1 Saeki K, Obayashi K, Kurumatani N. Indoor cold exposure and nocturia: a cross-sectional analysis of the HEIJO-KYO study. BJU Int 2016; 117: 82935



© 2024 BJU International. All Rights Reserved.