Low-calcium diet in hypercalciuric enuretic children restores AQP2 excretion and improves clinical symptoms
- 1 November 2002
- journal article
- clinical trial
- Published by American Physiological Society in American Journal of Physiology-Renal Physiology
- Vol. 283 (5) , F895-F903
Abstract
In this study, we analyzed the effect of a therapeutic intervention in 46 enuretic children, 26 (57%) of whom were hypercalciuric. All the patients ( n = 46) were treated with DDAVP for 3–6 mo. The hypercalciuric patients ( n = 26) received a low-calcium diet (∼500 mg/day) for the same period. After the therapy, the bed-wetting episodes stopped in 80% of the 46 patients tested. In those patients having low-AVP levels before the therapy, circulating AVP concentration returned to normal (>4 pg/ml), and the hypercalciuria was resolved in the hypercalciuric patients (calcium/creatinine ratio <0.2). Urinary aquaporin-2 (AQP2) levels were semiquantified by densitometric scanning and reported as a ratio between the intensity of the signal in the day vs. the night urine samples (day/night AQP2 ratio). In the hypercalciuric patients, the day/night AQP2 ratio returned to values close to those found in the healthy children (from 1.19 ± 0.20 before to 0.69 ± 0.10 after the treatment, n = 26, P = 0.03). In contrast, in the normocalciuric children we saw no significant modulation of AQP2 excretion (from 1.07 ± 0.14 before to 0.99 ± 0.14 after the treatment, n = 20). This study clearly demonstrates that urinary calcium levels modulate AQP2 excretion and is likely to be useful for treatment of children with enuresis.Keywords
This publication has 22 references indexed in Scilit:
- Defective Processing and Trafficking of Water Channels in Nephrogenic Diabetes insipidusNephron Experimental Nephrology, 2000
- Nocturnal Enuresis can be Caused by Absorptive HypercalciuriaScandinavian Journal of Urology and Nephrology, 1999
- Nephrogenic diabetes insipidusThe American Journal of Medicine, 1998
- Long‐term treatment with desmopressin in children with primary monosymptomatic nocturnal enuresis: an open multicentre studyBritish Journal of Urology, 1998
- Osmoregulatory Function of the Kidney in Enuretic ChildrenScandinavian Journal of Urology and Nephrology, 1998
- Urinary Excretion of Aquaporin-2 in the Diagnosis of Central Diabetes InsipidusThe Journal of Clinical Endocrinology & Metabolism, 1997
- Experience and current status of research into the pathophysiology of nocturnal enuresisBritish Journal of Urology, 1997
- Murine mucopolysaccharidosis type VII: long term therapeutic effects of enzyme replacement and enzyme replacement followed by bone marrow transplantation.Journal of Clinical Investigation, 1997
- Urinary Excretion of Aquaporin-2 in Patients with Diabetes InsipidusNew England Journal of Medicine, 1995
- Cloning and expression of apical membrane water channel of rat kidney collecting tubuleNature, 1993