Twenty-six subjects were divided into two groups: enuretics, and patients with various diseases but without enuresis. These subjects were studied to investigate the diurnal variation of urinary volume and of urinary total solute, Na, K, 17-OHCS and ADH excretions in urine at 3 hourly intervals over periods one to nine days.
The results are summarized as follows:
I. Variation in urinary volume, total solute, Na, and K excretion
A. Excretion of urinary volume and total solute
In the subjects with nocturnal enuresis in contrast with other subjects under ten years of age, urinary volume and total solute excretions increased both at night and in the day. There was in particular an increase in the volume of night urine and the volume of solute excretion at night and there was a reduction in the volume of total solute of daytime urine.
In the subjects in the 10-15 year age group, the enuretic group, as compared with other group, showed an increase in urinary volume and total solute excretions at night. And also the subjects above sixteen years of age showed a similar tendency.
B. Excretion of total solute and Na in urine.
It was noticed that the rate of Na excretion into total solute excretion was almost constant. In particular, a large relative excretion of total solute and Na in nighttime urine was observed in the groups under 10 years of age, in the 10-15 year group, and in the over 16 group.
C. Excretion of total solute and K in urine.
When the total solute increased, the volume of K in the total solute increased slightly but it could hardly be recognized that there was any fixed tendency in the rate of increase. Therefore, there was no significant difference between enuretics and other subjects.
II. Daily variation of urinary 17-OHCS level
In the group without enuresis under 10 years of age, the nocturnal values were the lowest, but the values increased rapidly in the early morning and decreased gradually in the afternoon. On the other hand, in the enuretic group, the urinary values were relatively low at night and increased slightly in the morning, but were low as a whole and the variation of them was only slight for all periods. Because measurements of the enuretic 10-15 year age group were infrequent, it was difficult to evaluate the difference between the enuretic group and the other group by the same criterion. But it would appear that the results for the subjects under 10 years of age were almost the same as those above.
In the group without enuresis above sixteen, the nocturnal values were low and rose in the morning and fell slowly in the afternoon. But in the enuretic group, quite a wide distribution was observed for all periods of the day and night, and it was difficult to perceive any definite trend of daily variation.
III. Diurnal variation of urinary ADH level in urine.
In the group without enuresis under 10 years of age, the urinary values were relatively low in the early morning and rose slightly in the forenoon. These values were maintained in the afternoon but fell at night. On the other hand, although scattered from night to day, the enuretic group showed very similar changes as compared with the group without enuresis. Later, cases with extremely high and extremely low values were found.
In the 10-15 year age group, it was difficult to evaluate the difference between the enuretic group and the group without enuresis, but in the enuretic group, it was observed that some enuretic subjects showed low values in the morning, and high values in the evening and at nighttime.
But in early morning and in the evening, cases with high values among the non-enuresis group were found in the over 16 year group, but apart from this there was no particular difference between the two group during the daytime.