Analysis of Nocturia Determinants Using a Novel Portable Urine-Measuring Device.

AIMS

To investigate the relationship between nocturia and values measured using a novel multifunctional portable urine-measuring device.

METHODS

Thirty-five older men with nocturia and/or high-normal or high blood pressure were enrolled to record measurements on one full day (24 h) and two nights using the portable device during urination. Participants used a semi-conical cup with a small hole equipped with a conductivity sensor, temperature sensor, and timer to measure urine volume, salt content, urine temperature, and urination speed.

RESULTS

Two participants were excluded owing to oliguria. The mean age of 33 participants was 75.2 ± 7.4 years (range: 55-85 years). The mean nocturnal urination frequency, including the first urination after waking, was 2.1 ± 0.6 times. Simple correlation analysis revealed that nocturnal urine frequency significantly increased with nocturnal urine volume (r = 0.65, p < 0.001) and salt content (r = 0.57, p < 0.001) but not with 24-h urine volume and salt content. Furthermore, the frequency significantly decreased with nocturnal urine temperature (r = -0.37, p < 0.05). No significant relationship was observed between morning blood pressure and nocturnal urination frequency. A high correlation was observed between nighttime urine volume and salt content (r = 0.73, p < 0.001).

CONCLUSIONS

Nocturnal urine volume, salt content, and urine temperature are significantly correlated with nocturia. The portable urine-measuring device could guide nocturia reduction through facilitation of the reduction of nocturnal urine volume and salt content, in addition to urine temperature monitoring.