Circadian rhythm disturbances in nocturia and nocturnal polyuria: A systematic review

Nocturia is a common symptom among adults and is often associated with disrupted sleep and diminished quality of life. In many cases, it is driven by nocturnal polyuria, an imbalance in nighttime urine production. Emerging evidence suggests that circadian rhythm disturbances, which regulate hormone secretion, renal function, and blood pressure, may play a role in this altered diuresis. This systematic review evaluated the contribution of circadian dysregulation to the pathophysiology of two distinct nocturnal voiding patterns: nocturia (defined by voiding frequency) and nocturnal polyuria (defined by urine production volume).

We systematically searched PubMed, Embase, and CINAHL for studies examining circadian factors, such as melatonin, vasopressin, natriuretic peptides, or nocturnal blood pressure patterns, in relation to nocturia or nocturnal polyuria. Eligible studies included adult populations, with no publication date restrictions. Studies addressing nocturnal polyuria and nocturia were analyzed separately to reflect distinct underlying mechanisms. Two reviewers independently screened articles, extracted data, and assessed study quality using the Newcastle-Ottawa Scale. Studies were categorized based on use of the clinical threshold for nocturia (≥2 voids per main sleep period), nocturnal polyuria, or subgroup analyses.

Fourteen studies met inclusion criteria. Across diverse populations and methodologies, circadian dysregulation was consistently linked to altered nocturnal urine production. Common findings included reduced nighttime melatonin and vasopressin levels, elevated natriuretic peptide secretion, and diminished nocturnal blood pressure dipping. These abnormalities were observed in older adults, patients with obstructive sleep apnea, and individuals with neurological conditions. Several studies also reported a blunting of normal diurnal variation in sodium excretion and urine concentration.

These findings underscore the importance of incorporating circadian rhythm assessment into the clinical evaluation of nocturnal urinary complaints.