In Older Men With Persistent Nocturia Due to Nocturnal Polyuria, Desmopressin Is Effective for Those With Higher Muscle Mass.

OBJECTIVES: To investigate the efficacy of desmopressin in older men with persistent nocturia due to nocturnal polyuria and then determine the independent factors affecting the efficacy of desmopressin. METHODS: Desmopressin 50 mg was administered for 12 weeks to 49 patients (76.3 ± 7.3 years) with persistent nocturia. Physical factors including prostate volume, muscle mass, basal metabolic rate, maximum flow rate, voiding diary, serum sodium, and scores of several questionnaires were evaluated. First, we evaluated the efficacy of desmopressin and then investigated the independent factors influencing its efficacy. RESULTS: Nocturnal urinary frequency decreased significantly from 3.9 ± 1.0 to 1.9 ± 1.1 times/night. The nocturnal urine volume and nocturnal polyuria index significantly decreased from 761.6 ± 273.8 to 445.5 ± 159.3 mL and from 45.5% ± 10.2% to 32.3% ± 14.4% respectively. The total International Prostate Symptom Score improved significantly, as did the Quality of Life index. However, the Overactive Bladder Symptom Score and the Athens Insomnia Scale did not show significant improvement. Only muscle mass at the baseline measurement was identified as a factor predictive of affecting the efficacy of desmopressin based on the decrease in nocturnal urinary frequency. CONCLUSIONS: This study is the first, to our knowledge, to determine the independent factors affecting the efficacy of desmopressin.