Overactive bladder sleep study links weaker daily rhythm to higher prevalence

An overactive bladder sleep study has linked weaker daily rest-activity patterns and less favorable sleep measures with a higher prevalence of overactive bladder. The findings, published July 17 in Neurourology and Urodynamics, suggest circadian and sleep health may be relevant to how researchers think about overactive bladder.

Renjie Huang of Heilongjiang University of Chinese Medicine in Harbin, China, and colleagues analyzed data from 6,603 adults in the National Health and Nutrition Examination Survey from 2011 to 2014, according to the study. The researchers used seven days of wrist-worn accelerometer readings to assess rest-activity rhythm and sleep-related measures.

The study was cross-sectional, meaning it looked at associations at one point in time rather than proving cause and effect. The authors said the findings need confirmation in prospective research.

What did the overactive bladder sleep study find?

Huang and colleagues reported that the weighted prevalence of overactive bladder was 21.4% among the adults included in the analysis. After full adjustment, stronger relative amplitude in the rest-activity pattern was tied to lower odds of overactive bladder, while greater intradaily variability was tied to higher odds, according to the study.

For each 0.1-unit rise in relative amplitude, the odds ratio for overactive bladder was 0.83, the researchers reported. For each 0.1-unit rise in intradaily variability, the odds ratio was 1.05.

Sleep measures also showed associations. The study found higher sleep efficiency was linked with lower odds of overactive bladder, with an odds ratio of 0.81 for each 10% increase. Longer sleep duration was also linked with lower odds, with an odds ratio of 0.95 for each additional hour, according to the researchers.

The investigators did not find independent associations for interdaily stability, social jet lag or catch-up sleep. They also reported that depression partly accounted for the relationship between relative amplitude and overactive bladder.

What is a rest-activity rhythm?

In this study, rest-activity rhythm refers to patterns derived from movement and rest data collected by wrist accelerometers over seven days. The researchers summarized those patterns using nonparametric metrics including interdaily stability, intradaily variability and relative amplitude.

Relative amplitude reflects the contrast in activity between active and rest periods, while intradaily variability captures fragmentation in the pattern, according to the measures used by the researchers. The study linked a lower-amplitude or more disrupted pattern with overactive bladder prevalence, but it did not show that the rhythm changes caused the bladder condition.

The authors wrote that the observational findings “require prospective validation” and support further study of whether behavioral approaches aimed at circadian and sleep health could complement overactive bladder management. The paper was titled “Association of Accelerometer-Derived Rest-Activity Rhythms and Sleep Health With Overactive Bladder: Depression as a Potential Explanatory Factor in a Nationally Representative Study.”

This story draws on original reporting from Medical Xpress.