Idiopathic hypercalciuria: Can we prevent stones and protect bones?

Abstract

Idiopathic hypercalciuria increases the risk of urinary stones and osteoporosis. The aim of this review is to delineate our current understanding of idiopathic hypercalciuria in the context of bone health, specifi cally its defi nition, causes, epidemiology, laboratory evaluation, and potential treatments. KEY POINTS Idiopathic hypercalciuria is common in patients with kidney stones and is also present in up to 20% of postmenopausal women with osteoporosis but no history of kidney stones. Idiopathic hypercalciuria has been directly implicated as a cause of loss of trabecular bone, especially in men. But reversing the hypercalciuria in this condition has not been defi nitively shown to diminish fracture incidence. Patients with kidney stones who have low bone mass and idiopathic hypercalciuria should increase their daily fluid intake, follow a diet low in salt and animal protein, and take thiazide diuretics to reduce the risk of further calcium stone formation. Whether this approach also improves bone mass and strength and reduces fracture risk in this patient group requires further study.