[A physiological analysis of kidney ion-regulating function in children with enuresis]

Area of Science:

• Pediatric Nephrology
• Urology
• Endocrinology

Background:

• Nocturnal enuresis is common in children, often linked to altered water and solute excretion.
• Understanding ion and water balance is crucial for managing enuresis.

Purpose of the Study:

• To investigate ion and water excretion peculiarities in children with nocturnal enuresis.
• To explore the role of osmotically active substances in enuretic diuresis.
• To evaluate the efficacy of 1-deamino-8-D-arginine-vasopressin (DDAVP) in normalizing excretion patterns.

Main Methods:

• Comparative analysis of ion (Na, K, Ca, Mg) and water excretion in healthy children versus those with nocturnal enuresis (aged 6-15).
• Development of a formula for quantifying osmolar clearance contributions.
• Assessment of the impact of intranasal DDAVP administration on ion excretion and water reabsorption.

Main Results:

• Enuretic children showed greater diuresis due to increased Na and Mg excretion, not K or Ca.
• A high correlation was observed between Na/Mg excretion and osmotic free water reabsorption.
• DDAVP administration normalized Na and Mg excretion in enuretic children.

Conclusions:

• Enuretic diuresis is linked to elevated Na and Mg excretion, potentially from impaired ion reabsorption in the thick ascending Henle loop.
• DDAVP normalizes ion transport by stimulating V2-receptors, offering a therapeutic mechanism.
• The study elucidates the interplay between ion excretion, water reabsorption, and DDAVP's action in pediatric enuresis.