1
|
Tostivint IN, Castiglione V, Alkouri R, Bertocchio JP, Inaoui R, Daudon M, Dousseaux MP, Cavalier E, Pieroni L, Izzedine H. How useful is an oral calcium load test for diagnosing recurrent calcium stone formers? Urolithiasis 2022; 50:577-587. [PMID: 35994082 DOI: 10.1007/s00240-022-01355-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 08/10/2022] [Indexed: 10/15/2022]
Abstract
Hypercalciuria is the main risk factor for recurrent calcium urolithiasis. The goal of our study is to determinate how useful an oral calcium load test is for stone formers to classify different forms of hypercalciuria in pathogenetic categories defined as renal or absorptive according to the current knowledge. Between June 2013 and February 2016, a prospective study was carried out on 117 documented recurrent hypercalciuric stone formers undergoing an oral calcium load test modified from the original description by Pak. After 2 days of calcium-restricted diet, urine and blood were analyzed at baseline and 120 min after receiving orally 1 g of calcium. Total and ionized calcium, parathyroid hormone from serum and urine calcium and creatinine were assessed in order to divide patients in three groups as previously described: resorptive, absorptive, and renal hypercalciuria. This allowed the identification of 19, 39, 34 and 33 patients with normocalcemic primary hyperparathyroidism (NPHPT), renal hypercalciuria aka renal calcium leak (RCL), absorptive hypercalciuria (AH) and unidentified cause, respectively. Patients with NPHPT (who required parathyroidectomy) experienced a lower PTH decrease (41.41 ± 12.82 vs. 54.06 ± 13.84% p < 0.01), higher beta-crosslaps, as well as lower TmP/GFR and distal third radius bone mineral density. RCL resulted in increased fasting urine calcium-to-creatinine ratio (Uca/Cr), i.e., > 0.37 mmol/mmol), without hyperparathyroidism. AH was diagnosed by the presence of ΔUCa/Cr > 0.60 mmol/mmol between baseline and 120 min without any other anomaly. For all remaining patients, results were inconclusive due to the lack of sufficient increase in serum calcium or because the cause of lithogenesis could not be clearly identified. The oral calcium load test is useful in nearly 80% of patients by identifying the different forms of hypercalciuria causing urolithiasis and by guiding treatment, including parathyroid surgery.
Collapse
Affiliation(s)
- Isabelle N Tostivint
- Department of Nephrology, AP-HP, Pitie Salpetriere Hospital, 48 Boulevard de l'Hôpital, 75013, Paris, France.
- GRC 20 SORBONNE UNIVERSITY Clinical multidisciplinary Research Group on Kidney Stones, Sorbonne University Tenon Hospital, Paris, France.
| | - Vincent Castiglione
- Department of Clinical Chemistry, University Hospital of Liege, Liege, Belgium
| | - Rana Alkouri
- Department of Metabolic Biochemistry, AP-HP, Pitie Salpetriere Hospital, Paris, France
| | - Jean Philippe Bertocchio
- Department of Nephrology, AP-HP, Pitie Salpetriere Hospital, 48 Boulevard de l'Hôpital, 75013, Paris, France
- Rare Diseases Network OSCAR, Center for Excellence in Rare Calcium and Phosphate Disorders, Paris, France
| | - Rachida Inaoui
- Department of Rheumatology, AP-HP, Pitie Salpetriere Hospital, Paris, France
| | - Michel Daudon
- Department of Biochemistry, Cristal Laboratory, AP-HP, Tenon Hospital, Paris, France
| | - Marie-Paule Dousseaux
- Department of Nutrition and Dietetics, AP-HP, Pitie Salpetriere Hospital, Paris, France
| | - Etienne Cavalier
- Department of Clinical Chemistry, University Hospital of Liege, Liege, Belgium
| | - Laurence Pieroni
- Department of Metabolic Biochemistry, AP-HP, Pitie Salpetriere Hospital, Paris, France
- Department of Biochemistry, Cristal Laboratory, AP-HP, Tenon Hospital, Paris, France
| | - Hassan Izzedine
- Department of Nephrology, Peupliers Private Hospital, Paris, France
| |
Collapse
|