Renal hypercalciuria: ¿Is it different from idiopathic hypercalciuria?

Abstract

Introduction: Idiopathic hypercalciuria is the leading risk factor in oxalo-calcium stones and a secondary cause of osteoporosis. It occurs in families with a probably polygenic trait, which involves alterations in intestinal, bone, and renal calcium management. Some studies suggest that more than 50% of calcium excretion is genetically determined, most frequently observed in first-degree relatives. The objective of our study was to evaluate whether there are clinical, biochemical, and densitometric differences between patients with renal hypercalciuria and idiopathic hypercalciuria. Material and methods: 112 hypercalciuric patients were included, half with elevated PTH. Results: Renal hypercalciuric patients, Group I (n = 56) were older (p < 0.001) and heavier (p < 0.05) than patients with idiopathic hypercalciuria Group II (n = 56). A higher level of iPTH (p <0.001) and serum crosslap (p <0.05) was presented in patients with renal hypercalciuria. No significant differences were found between the groups in the presence of kidney stones and bone density. According to the presence (n = 32) or absence (n = 24) of kidney stones in Group I (renal hypercalciuria), there were also no significant changes. Conclusion: renal hypercalciuria is a variant of idiopathic hypercalciuria, which to date does not show significant differences with the remaining variants of idiopathic hypercalciuria. Prospective studies with longer-term follow-ups, including genetic evaluation, will confirm the existence or absence of these differences.