Preliminary Experience with Low-dose Desmopressin Treatment and Urinary Arginine Vasopressin Concentration as a Response Predictor for Patients with Nocturia with Nocturnal Polyuria

Night-to-Day Ratio of Excreted Urinary Sodium Concentration Using Spot Urine in Older Adults With Nocturnal Polyuria

BACKGROUND

The diurnal rhythm in water and solute diuresis is known to be disturbed in older adults with nocturia due to nocturnal polyuria. We estimated the prevalence of increased natriuresis in nocturia due to nocturnal polyuria by comparing individuals with and without nocturnal polyuria.

METHODS

We calculated the night-to-day ratio of excreted urinary sodium and potassium concentrations adjusted for urinary creatinine concentration and urinary osmolality using spot urine samples collected at 2 PM (daytime) and 6 AM (nighttime) and compared results among controls with nocturia and paitents with nocturia with and without nocturnal polyuria.

RESULTS

Among 83 patients aged 50 to 86 years, the mean night-to-day ratio of excreted urinary sodium and potassium concentrations in the nocturia group with nocturnal polyuria (n = 40) was 2.5, which was significantly higher (p = 0.034) than those in the control group (n = 23; 0.7) and the nocturia group without nocturnal polyuria (n = 20; 0.9). After adjustment for age, no difference in potassium and urinary osmolality existed among groups. Thirteen patients (33%) in the nocturia group with nocturnal polyuria showed increased natriuresis when a 2.0 night-to-day ratio of excreted urinary sodium was applied as a cut-off for increased natriuresis, whereas only 3 (7%) patients in the combined groups without nocturnal polyuria had increased natriuresis (p = 0.005).

CONCLUSIONS

One-third of patients with nocturia due to nocturnal polyuria had increased natriuresis. Assessment of a night-to-day ratio of excreted urinary sodium using spot urine samples could facilitate a better understanding of the underlying pathophysiology and optimal management of nocturnal polyuria.

Pharmacologic management of nocturnal polyuria: a contemporary assessment of efficacy, safety, and progress toward individualized treatment

This narrative review synthesizes current evidence on the medical management of nocturnal polyuria, including antidiuretic replacement therapy as well as other emerging modalities, with particular emphasis on areas of active investigation and future research directions. Relative to earlier formulations, the pharmacological profiles of novel desmopressin acetate nasal spray and orally disintegrating tablet formulations appear favorable in optimizing the balance between efficacy and safety. Additionally, several highly selective small-molecule arginine vasopressin 2 receptor agonists are under active development, while appropriately timed short-acting diuretics, pharmacotherapy for hypertension, nonsteroidal anti-inflammatory drugs, and sex hormone replacement therapy are also a focal point of extensive ongoing nocturnal polyuria research. Emerging laboratory technologies now make feasible a sub-stratification of nocturnal polyuria patients into substrate-based phenotypes for individualized treatment. An increasingly refined understanding of the pathogenesis of nocturnal polyuria, and arginine vasopressin dysregulation in particular, has also introduced new opportunities for point-of-care testing in patients with nocturnal polyuria.