BACKGROUND: Bone mineral density (BMD) is reduced among patients with idiopathic hypercalciuria (IH) and nephrolithiasis. To disentangle effects of diet, stone formation, and physiology upon BMD, we studied vertebral and femoral neck BMD among relatives of hypercalciuric stone formers, and contrasted those with to those without stones. METHODS: Among 59 subjects from 11 families, vertebral and femoral neck BMD, diet calcium intake, urine excretions of calcium, sodium, ammonium, titratable acid, sulfate, urea nitrogen, and serum levels of calcitriol and markers of bone turnover were studied. RESULTS: Stone formers (SF) consumed less calcium than non-stone formers (NSF). Spine and femoral neck BMD z-scores varied inversely with urine calcium loss and urine ammonium excretion among SF but not NSF. No correlations of BMD z-score were found for bone markers, calcitriol, or any of the other measurements. CONCLUSION: SF consumed less calcium, presumably to prevent more stones, and displayed a bone mineral responsiveness to calcium loss and ammonium excretion not present among NSF, who ate more calcium. Lowered calcium consumption in IH, perhaps in response to stone formation, alters bone responses in a direction that can predispose to mineral loss and eventual fracture.
BACKGROUND: Bone mineral density (BMD) is reduced among patients with idiopathic hypercalciuria (IH) and nephrolithiasis. To disentangle effects of diet, stone formation, and physiology upon BMD, we studied vertebral and femoral neck BMD among relatives of hypercalciuric stone formers, and contrasted those with to those without stones. METHODS: Among 59 subjects from 11 families, vertebral and femoral neck BMD, diet calcium intake, urine excretions of calcium, sodium, ammonium, titratable acid, sulfate, ureanitrogen, and serum levels of calcitriol and markers of bone turnover were studied. RESULTS: Stone formers (SF) consumed less calcium than non-stone formers (NSF). Spine and femoral neck BMD z-scores varied inversely with urine calcium loss and urine ammonium excretion among SF but not NSF. No correlations of BMD z-score were found for bone markers, calcitriol, or any of the other measurements. CONCLUSION: SF consumed less calcium, presumably to prevent more stones, and displayed a bone mineral responsiveness to calcium loss and ammonium excretion not present among NSF, who ate more calcium. Lowered calcium consumption in IH, perhaps in response to stone formation, alters bone responses in a direction that can predispose to mineral loss and eventual fracture.
Authors: Gudmar Thorleifsson; Hilma Holm; Vidar Edvardsson; G Bragi Walters; Unnur Styrkarsdottir; Daniel F Gudbjartsson; Patrick Sulem; Bjarni V Halldorsson; Femmie de Vegt; Frank C H d'Ancona; Martin den Heijer; Leifur Franzson; Claus Christiansen; Peter Alexandersen; Thorunn Rafnar; Kristleifur Kristjansson; Gunnar Sigurdsson; Lambertus A Kiemeney; Magnus Bodvarsson; Olafur S Indridason; Runolfur Palsson; Augustine Kong; Unnur Thorsteinsdottir; Kari Stefansson Journal: Nat Genet Date: 2009-06-28 Impact factor: 38.330
Authors: Laura D Carbone; Kathleen M Hovey; Christopher A Andrews; Fridtjof Thomas; Mathew D Sorensen; Carolyn J Crandall; Nelson B Watts; Monique Bethel; Karen C Johnson Journal: J Bone Miner Res Date: 2015-07-14 Impact factor: 6.741