title: Urine calcium excretion predicts bone loss in idiopathic hypercalciuria.
abstract: Although idiopathic hypercalciuria (IH) is associated with reduced bone mineral density (BMD), no studies to date have identified predictors of BMD change over an extended period of observation. We have studied change in femoral neck and spine BMD z-scores in men and women with IH and stone disease (IHSF) and their first-degree relatives in order to determine the predictive value of commonly made clinical measurements. Urine calcium excretion was inversely correlated with change in femoral neck z-score over 3 years, and marginally correlated with fall in spine z-score. Markers of bone turnover, serum calcitriol, and urine measurements of acid-base balance such as ammonium and sulfate had no predictive value, nor did calcium intake assessed using a well-established questionnaire. It would appear that IHSF with the highest 24-h urine calcium excretion rates are at highest risk for loss of femoral neck bone mineral over a 3-year period.
authors.affiliation: Litholink Corporation, University of Chicago, Chicago, Illinois 60612, USA. jasplin@litholink.com
authors.forename: J R
authors.initials: JR
authors.lastname: Asplin
authors.forename: S
authors.initials: S
authors.lastname: Donahue
authors.forename: J
authors.initials: J
authors.lastname: Kinder
authors.forename: F L
authors.initials: FL
authors.lastname: Coe
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood; D015519:Bone Density / Q000502:physiology*; D001862:Bone Resorption / Q000097:blood / Q000503:physiopathology* / Q000652:urine*; D001842:Bone and Bones / Q000378:metabolism* / Q000503:physiopathology*; D002117:Calcitriol / Q000097:blood; D002118:Calcium / Q000652:urine*; D015331:Cohort Studies; D003094:Collagen / Q000097:blood; D005260:Female; D005272:Femur Neck / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D006909:Hydroxyproline / Q000097:blood; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D000644:Quaternary Ammonium Compounds / Q000652:urine; D013131:Spine / Q000378:metabolism / Q000503:physiopathology
chemical_list: D000644:Quaternary Ammonium Compounds; D003094:Collagen; D000469:Alkaline Phosphatase; D002117:Calcitriol; D006909:Hydroxyproline; D002118:Calcium