Introduction and hypothesis: Can diary-derived bladder and sleep measurements differentiate individuals with overactive bladder syndrome (OAB) from individuals with primary insomnia and healthy controls?
Methods: Bladder- and sleep-diary data were compared in nine OAB, ten insomnia, and five control individuals. One-way analysis of variance (ANOVA) was used for normally and Kruskal-Wallis test for nonnormally distributed variables, followed, when significant effects were found, by pairwise comparisons.
Results: OAB individuals woke up as frequently as insomniacs, but their awakenings were respectively shorter in duration (18.6 vs. 38.1 min.) and were predominantly initiated by nocturic events (89.2 vs. 23.9 % respectively). Regardless, their reported quality of sleep was as impaired as for the insomniacs. Furthermore, smaller mean volume voided awakenings were evident not only in those with OAB but also in insomniacs compared to controls.
Conclusions: Bladder- and sleep-diary data provide means to differentiate those with OAB from those with insomnia and healthy controls. Awakenings in OAB individuals were shorter than those with insomnia and much more likely due to the need to void. Thus, a reduction in the number of nocturic voids could be the most appropriate sleep-related outcome for nocturia therapy in individuals with OAB. In addition, limited nocturnal bladder capacity, though expected in OAB, was unexpectedly found in insomnia, possibly reflecting the role of consciousness (wakefulness at night) in modulating bladder sensation.