Nocturnal polyuria and natriuresis in male patients with nocturia and lower urinary tract symptoms.

PURPOSE: We investigated the circadian variation in urine output, plasma angiotensin II, aldosterone, atrial natriuretic peptide, arginine vasopressin and blood pressure.

MATERIALS AND

METHODS

We studied 17 elderly men with nocturia and lower urinary tract symptoms, and 10 age matched controls without nocturia.

RESULTS

Of the 17 patients studied 11 had a lack of diurnal variation in urine output and increased nocturnal urine production associated with increased nocturnal sodium excretion, and 6 had a diurnal variation in urine output comparable to controls.

CONCLUSIONS

Nocturia in a large proportion of elderly men with lower urinary tract symptoms is caused by nocturnal polyuria and natriuresis.