Nocturnal enuresis can be caused by absorptive hypercalciuria.

OBJECTIVE

The aim of this study was to determine whether nocturnal enuresis (NE) can be caused by absorptive hypercalciuria.

METHODS

From 1981 to 1995, 406 patients with primary monosymptomatic nocturnal enuresis were studied. Up to 1989 (Group 1), urinary electrolytes and urinary creatinine were not evaluated, but since 1990 (Group 2) these tests have been performed routinely. In doing so, we noticed that in 8 patients in Group 2 and in 13 patients in Group 1 with persistent NE the urinary calcium and the urinary calcium/creatinine ratios were significantly high (p < 0.001). These patients were submitted to Pak's test and parathyroid hormone (PTH) and antidiuretic hormone (ADH) measurements.

RESULTS

In all 21 patients, PTH and ADH levels were normal, while the Pak's test showed absorptive hypercalciuria. They were given an appropriate diet. After 3 months, NE had ceased completely in 4 patients (19%); bedwetting episodes diminished and calciuria levels were found to be borderline in the remaining 17. A new urodynamic evaluation showed normal patterns in 12 and detrusor instability (DI) in 5. Patients with DI received oxybutinine: enuresis disappeared in all. The remaining 12 children with persistent NE and normal urodynamic findings and the child with DI and persistent NE empirically received DDAVP; enuresis ceased in all of them within 1 month and calciuria stabilized at normal levels.

CONCLUSIONS

This study revealed that absorptive hypercalciuria can be responsible for NE and can be treated with the combination of diet and DDAVP.