Urine calcium excretion predicts bone loss in idiopathic hypercalciuria

Kidney Int. 2006 Oct;70(8):1463-7. doi: 10.1038/sj.ki.5001778. Epub 2006 Aug 30.


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.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Absorptiometry, Photon
  • Adult
  • Aged
  • Alkaline Phosphatase / blood
  • Bone Density / physiology*
  • Bone Resorption / blood
  • Bone Resorption / physiopathology*
  • Bone Resorption / urine*
  • Bone and Bones / metabolism*
  • Bone and Bones / physiopathology*
  • Calcitriol / blood
  • Calcium / urine*
  • Cohort Studies
  • Collagen / blood
  • Female
  • Femur Neck / metabolism
  • Femur Neck / physiopathology
  • Humans
  • Hydroxyproline / blood
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Prospective Studies
  • Quaternary Ammonium Compounds / urine
  • Spine / metabolism
  • Spine / physiopathology


  • Quaternary Ammonium Compounds
  • Collagen
  • Alkaline Phosphatase
  • Calcitriol
  • Hydroxyproline
  • Calcium