Nocturia is more than an isolated lower urinary tract symptom, being significantly associated with dysfunction of sleep quality and duration, cardiovascular morbidity, mental health and mortality [1]. The medical conditions co-existing with nocturia may share central neural control areas in the brainstem [2,3]. The aim of this study was to investigate whether improvement in one comorbid variable, the overactive bladder, in patients with nocturia may regulate other co-morbid dysfunctions toward a more normal state.

A prospective, 2-arm repeated measures study was performed at both a tertiary Continence Service and a Sleep Medicine Service with recruitment between April and September 2017. Inclusion criteria: ≥40 years of age, nocturia and urinary urgency or urge incontinence severe enough to require pharmacotherapy. Exclusion criteria were current urinary tract infection, end-stage renal disease, bladder cancer, previous pelvic radiotherapy, pregnancy, urinary catheterisation and dementia or cognitive impairment that precluded completion of study tasks. Patients not able to complete questionnaires in English were also excluded from the study.

Baseline data included demographic information, overactive bladder symptom score (OABSS), Nocturia-specific quality of life instrument (NQoL), Epworth Sleepiness Scale (ESS), Pittsburg Sleep Quality Index (PSQI), Hospital Anxiety and Depression Scale (HADS) and Euroquol-5D Health Questionnaire (EQ-5D). Patients completed a 2-day bladder diary, and wore a wristband actigraphy device to detect sleep, waking and movement over a 5-day period. Postural blood pressures were measured.

Study intervention was either an anticholinergic agent or beta-3 agonist (mirabegron) to treat urgency or urgency incontinence. Patients were followed up regularly and reviewed after 12 weeks of treatment.  Data were re-collected at 12 weeks.

Findings from the Continence Service arm are presented in Table 1.Overall  n= 20, 65% female with a mean age of 65 years (SD 13.5) and health status on EQ-5D of 74/100. Half the cohort were retired, 20% were employed. Full compliance with medication was reported by 78% of participants. As expected, the OABSS was significantly reduced (p=0.04), however, neither maximum nor average day voided volumes increased. No changes were noted in HADS depression or anxiety scores, EQ-5D health score or night pain.

In a cohort of younger, relatively healthy individuals, treatment of daytime OAB resulted in less nocturia, improved sleep quality, longer duration of restorative slow wave sleep and a reduction in clinically relevant systolic blood pressure. There were no changes in bladder storage, diuresis, nocturnal polyuria index or QOL to explain the findings.

Nocturia and other co-morbid dysfunctions were shown to improve when severity of overactive bladder symptoms was reduced. Treatment of OAB, appears to have induced change toward a more normal state in other variables known to have control areas in the brainstem.

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Bower WF et al. Nocturia as a marker of poor health: Causal associations to inform care. Neurourol Urodyn. 2017 Mar;36(3):697-705. doi: 10.1002/nau.23000. Epub 2016 Apr 6.