THE ARGININE-VASOPRESSIN SECRETION PROFILE OF CHILDREN WITH PRIMARY NOCTURNAL ENURESIS

Objective: The aim of this group of studies was to determine the relat ionship between primary nocturnal enuresis and arginine-vasopressin (A VP) secretion. Methods: The first study compared the 24-hour AVP secre tion profiles of an enuretic group and a control group. Blood samples were collected every hour. In the second study, we compared nocturnal AVP secretion in group A, with low urinary osmotic pressure (UOP) and large nocturnal urinary volume (NUV), with that of group D, with norma l UOP and small NUV. The plasma AVP level was measured at 30-min sampl ing intervals. In the third study, the change in nocturnal AVP secreti on from before to after treatment was determined. Results: The plasma AVP level was significantly lower in the enuretic group from 23:00 thr ough 04:00 h. The mean plasma AVP level was significantly lower in gro up A than in group D at all points of measurement. The mean nocturnal AVP level in group A (0.64 +/- 0.23 pg/ml) was lower than that in grou p D (1.43 +/- 0.72 pg/ml) (p< 0.0001). The mean nocturnal AVP level af ter treatment was significantly increased, from 0.47 pg/ml before trea tment to 0.78 pg/ml after treatment (p = 0.01). However, a significant increase was noted in only 10 cases. Conclusions: These findings sugg est that decreased nocturnal AVP secretion is one of the causes of bed -wetting. However, the improvement of bed-wetting was not solely due t o the increased nocturnal AVP secretion.