| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 3905156 | Urology | 2007 | 5 Pages |
ObjectivesTo determine the cutoff value of early-morning urinary arginine vasopressin (uAVP)/urinary creatinine (uCr) for patients with nocturnal polyuria (NP), and to investigate whether abnormal secretion of AVP at nighttime is a risk factor of NP in elderly men.MethodsA total of 189 men older than 50 years of age with nocturia were enrolled. The frequency volume chart was recorded. The uAVP, urinary sodium, uCr, and osmolarity of a single urine sample voided at 6:00 am were measured in all cases. Two definitions of NP—nocturnal urine volume/24-hr production greater than 0.35 (NP index [NPI] definition) and a nocturnal urine volume of 0.9 mL/min × the sleeping duration or greater (NUV definition)—were used for analysis.ResultsuAVP/uCr was an independent predictor for NP according to the NPI and NUV definitions. The cutoff value of uAVP/uCr for NP was 23.4 pg/mL/Cr according to the NPI definition and 28.3 pg/mL/Cr according to the NUV definition. The sensitivity of the cutoff value according to the NPI and NUV definitions was 69% and 77%, respectively, and the specificity was 61% and 66%, respectively. In both NP definitions, 31% and 38% of the patients with a uAVP/uCr greater than the cutoff value showed NP. Significant differences in NUV and urine osmolarity, but not in uAVP/uCr and uNa/uCr, between the NP group and the non-NP group were found using both NP definitions.ConclusionsWe demonstrated that age and uAVP/uCr were independent predictive factors for nocturia in patients with NP. The cutoff value of uAVP/uCr is a useful screening marker for NP in elderly men with nocturia.
