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[Study of the renal acidification capacity in children diagnosed of idiopathic hypercalciuria]
V García Nieto1, M Monge, L Hernández Hernández
1Unidad de Nefrología Pediátrica, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife.
Insights
Children with idiopathic hypercalciuria have normal renal acidification capacity, particularly when assessed with sodium bicarbonate stimulus. Diuretic-induced tests may yield less reliable results for evaluating H+ secretion.
Area of Science:
- Pediatric Nephrology
- Renal Physiology
- Urolithiasis Research
Background:
- Idiopathic hypercalciuria (IH) is a common cause of kidney stones in children.
- Assessing renal acidification capacity is crucial for understanding IH.
- Previous studies have yielded conflicting results regarding renal acidification in IH.
Purpose of the Study:
- To evaluate the renal acidification capacity in children diagnosed with idiopathic hypercalciuria.
- To compare the effectiveness of different stimuli in assessing H+ secretion in IH.
Main Methods:
- Studied 36 children with IH and control groups.
- Measured maximum urinary pCO2 (UpCO2) using acetazolamide and sodium bicarbonate (NaHCO3) stimuli.
- Performed acidification tests with frusemide stimulus.
Main Results:
- No significant differences in UpCO2 or urinary HCO3- (UHCO3-) between IH patients and controls with NaHCO3 and acetazolamide.
- Significantly lower UpCO2 and UHCO3- in IH patients with acetazolamide compared to NaHCO3.
- Lower titratable acid and ammonium excretion in IH patients during frusemide-stimulated acidification tests.
Conclusions:
- Renal H+ secretion capacity is normal in children with IH, best demonstrated by NaHCO3-stimulated UpCO2.
- Diuretic-induced stimuli may provide less conclusive results due to potential resistance or lower potency in H+ secretion.
- Further research is needed to clarify the role of diuretics in assessing renal acidification in IH.
Objective:
To study the capacity of renal acidification in a group of children diagnosed of idiopathic hypercalciuria.
Patient And Methods:
36 children were studied, to those that were determined the pCO2 (UpCO2) maximum urinary with two different stimuli, acetazolamide and sodium bicarbonate (NaHCO3). At 33 of them, was performed an acidification test with frusemide stimulus. We studied a control group of 13 healthy children so much for the first one as the second tests and other 14 healthy children for the acidification test with frusemide.
Results:
In the tests performed with NaHCO3 and acetazolamide stimulus, they were not proven differences in the values of UpCO2 neither in the urinary concentration of HCO3- (UHCO3-) than control children. Nevertheless, the UpCO2 and the concentration of UHCO3- in the patients were significantly lower with acetazolamide with regard to the NaHCO3 stimulus. In the acidification test with frusemide, significantly lower values of titratable acid and ammonium were obtained than control children.
Conclusions:
In children with idiopathic hypercalciuria, the capacity of secretion of H+ is normal, what is evidenced, especially, when studying the maximum UpCO2 after stimulus with NaHCO3. When diuretics are used as stimuli, exists more negative results that can be due to a certain partial resistance to the action of the same ones or to that are less potent to induce the secretion of H+.
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