Urine calcium excretion predicts bone loss in idiopathic hypercalciuria

Area of Science:

• Nephrology
• Endocrinology
• Bone Metabolism

Background:

• Idiopathic hypercalciuria (IH) is linked to lower bone mineral density (BMD).
• Predictors for BMD changes in IH patients over time remain unidentified.
• Bone health in IH patients and their relatives requires further investigation.

Purpose of the Study:

• To identify predictors of bone mineral density (BMD) changes in idiopathic hypercalciuria with stone formers (IHSF) and their relatives.
• To assess the predictive value of clinical measurements for BMD changes over an extended period.
• To determine if urine calcium excretion predicts bone loss in IHSF.

Main Methods:

• Longitudinal study tracking femoral neck and spine BMD z-scores in men and women with IHSF and their first-degree relatives.
• Analysis of correlations between baseline clinical measurements and BMD changes over 3 years.
• Evaluation of urine calcium excretion, bone turnover markers, serum calcitriol, urine acid-base balance, and dietary calcium intake.

Main Results:

• Higher 24-hour urine calcium excretion was inversely correlated with changes in femoral neck BMD z-scores over 3 years.
• Urine calcium excretion showed a marginal correlation with the decline in spine BMD z-scores.
• Bone turnover markers, serum calcitriol, urine acid-base balance, and dietary calcium intake did not predict BMD changes.

Conclusions:

• Individuals with idiopathic hypercalciuria and kidney stones (IHSF) exhibiting the highest 24-hour urine calcium excretion rates are at increased risk for femoral neck bone mineral loss.
• Urine calcium excretion is a significant predictor of bone loss at the femoral neck in this population.
• Further research should focus on managing hypercalciuria to mitigate bone loss in affected individuals.