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Hypercalciuria: its value as a predictive risk factor for nephrolithiasis in asymptomatic primary
F Saponaro1,2, F Cetani3, L Mazoni3
1Department of Pathology, University of Pisa, Pisa, Italy. federica.saponaro@unipi.it.
Journal of Endocrinological Investigation
|December 25, 2019
Summary
Hypercalciuria predicts kidney stones in patients with asymptomatic primary hyperparathyroidism (aPHPT). However, this urinary calcium excretion has a low positive predictive value for identifying nephrolithiasis.
Area of Science:
- Endocrinology
- Nephrology
- Urology
Background:
- Recent guidelines for asymptomatic primary hyperparathyroidism (aPHPT) include hypercalciuria as a surgical criterion.
- The predictive value of hypercalciuria for nephrolithiasis requires further validation.
Purpose of the Study:
- To determine the prevalence of silent kidney stones in aPHPT patients.
- To assess the sensitivity, specificity, and predictive value of various hypercalciuria cut-offs for detecting nephrolithiasis.
Main Methods:
- 176 patients with aPHPT underwent evaluation of serum and urinary parameters.
- Kidney ultrasound was used to identify silent nephrolithiasis.
Main Results:
- Silent kidney stones were detected in 21.6% of patients.
- Hypercalciuria was a significant predictor of nephrolithiasis across multiple criteria (e.g., >400 mg/24h, >231 mg/24h).
- Despite predictive significance, the positive predictive value of hypercalciuria for nephrolithiasis was low (27.4-32.7%).
Conclusions:
- Hypercalciuria is a validated predictor of nephrolithiasis in aPHPT.
- The low positive predictive value of hypercalciuria limits its utility in routine screening for kidney stones.
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