{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,11]],"date-time":"2026-02-11T20:55:22Z","timestamp":1770843322135,"version":"3.50.1"},"reference-count":19,"publisher":"Oxford University Press (OUP)","issue":"2","license":[{"start":{"date-parts":[[2024,12,10]],"date-time":"2024-12-10T00:00:00Z","timestamp":1733788800000},"content-version":"vor","delay-in-days":1,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,2,3]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n               <jats:sec>\n                  <jats:title>Introduction<\/jats:title>\n                  <jats:p>The calcium load test (CLT) was developed by Pak et\u00a0al. in 1974 to better discriminate hypercalciuria. Absorptive hypercalciuria (AH) is defined by an increase of the difference between urinary calcium\/creatinine ratio (\u0394UCa\/Cr) of more than 0.5\u00a0mmol\/mmol with a 4-hour CLT. In clinical practice and more recent studies, CLT is a 2-hour test. We hypothesized that the 4\u00a0h timepoint is more efficient in AH diagnosis.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>We report a single-centre retrospective study including all patients who underwent CLT because of hypercalciuria or hyperparathyroidism. After a 3-day low-calcium diet and a 12-hour fast, 24-hour urines were collected. Blood and urinary samples were done at arrival and after 2\u00a0h and 4\u00a0h of oral ingestion of 1\u00a0g of calcium. AH was diagnosed by \u0394UCa\/Cr between baseline and 2\u00a0h or 4\u00a0h of more than 0.05\u00a0mmol\/mmol.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>We included 328 patients. Baseline UCa\/Cr ratio was 0.3\u00a0\u00b1\u00a00.2\u00a0mmol\/mmol and increased significantly after 2\u00a0h and 4\u00a0h (0.6\u00a0\u00b1\u00a00.3 and 0.8\u00a0\u00b1\u00a00.4\u00a0mmol\/mmol, P\u00a0&amp;lt;\u00a00.001). \u0394UCa\/Cr was significantly different between baseline and 2\u00a0h or 4\u00a0h (0.2\u00a0\u00b1\u00a00.2 versus 0.5\u00a0\u00b1\u00a00.4, P\u00a0&amp;lt;\u00a00.001). AH was diagnosed in 35 (10.7%) patients after 2\u00a0h, 84 (25.6%) more were diagnosed at 4\u00a0h (P\u00a0&amp;lt;\u00a00.001).<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>The 4\u00a0h CLT improves the diagnosis of AH with more than 50% of AH diagnosed within 4\u00a0h of calcium ingestion. It seems that there are cases of AH of later diagnosis with a similar clinical and biological profile depending on enteral absorption.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1093\/ckj\/sfae399","type":"journal-article","created":{"date-parts":[[2024,12,11]],"date-time":"2024-12-11T01:12:10Z","timestamp":1733879530000},"source":"Crossref","is-referenced-by-count":1,"title":["Improving the diagnostic of absorptive hypercalciuria: a comparative analysis of calcium load tests at 2-hour and 4-hour intervals"],"prefix":"10.1093","volume":"18","author":[{"given":"Lara","family":"Cabezas","sequence":"first","affiliation":[{"name":"Service de N\u00e9phrologie, HTA, dialyse et explorations fonctionnelles r\u00e9nales, Hopital Edouard Herriot, Hospices civils de Lyon , Lyon ,","place":["France"]},{"name":"Nephrology, Hemodialysis, Apheresis and Kidney Transplantation Department, University Hospital Grenoble , Grenoble ,","place":["France"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pierre","family":"Letourneau","sequence":"additional","affiliation":[{"name":"Service de N\u00e9phrologie, HTA, dialyse et explorations fonctionnelles r\u00e9nales, Hopital Edouard Herriot, Hospices civils de Lyon , Lyon ,","place":["France"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Aur\u00e9lie","family":"De Mul","sequence":"additional","affiliation":[{"name":"Service de N\u00e9phrologie, HTA, dialyse et explorations fonctionnelles r\u00e9nales, Hopital Edouard Herriot, Hospices civils de Lyon , Lyon ,","place":["France"]},{"name":"INSERM 1060-CARMEN, Universit\u00e9 de Lyon , Universit\u00e9 Lyon 1, Lyon ,","place":["France"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0578-2529","authenticated-orcid":false,"given":"Justine","family":"Bacchetta","sequence":"additional","affiliation":[{"name":"Centre de R\u00e9f\u00e9rence des Maladies R\u00e9nales Rares, Centre de R\u00e9f\u00e9rence des Maladies Rares du Calcium et du Phosphore, HFME , Bron ,","place":["France"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3462-4239","authenticated-orcid":false,"given":"Laurence","family":"Chardon","sequence":"additional","affiliation":[{"name":"Hospices civils de Lyon, Groupement hospitalier Est, Service de biochimie , Lyon ,","place":["France"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Laurence","family":"Derain Dubourg","sequence":"additional","affiliation":[{"name":"Service de N\u00e9phrologie, HTA, dialyse et explorations fonctionnelles r\u00e9nales, Hopital Edouard Herriot, Hospices civils de Lyon , Lyon ,","place":["France"]},{"name":"Centre de R\u00e9f\u00e9rence des Maladies R\u00e9nales Rares, Centre de R\u00e9f\u00e9rence des Maladies Rares du Calcium et du Phosphore, HFME , Bron ,","place":["France"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3460-2507","authenticated-orcid":false,"given":"Sandrine","family":"Lemoine","sequence":"additional","affiliation":[{"name":"Service de N\u00e9phrologie, HTA, dialyse et explorations fonctionnelles r\u00e9nales, Hopital Edouard Herriot, Hospices civils de Lyon , Lyon ,","place":["France"]},{"name":"INSERM 1060-CARMEN, Universit\u00e9 de Lyon , Universit\u00e9 Lyon 1, Lyon ,","place":["France"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"286","published-online":{"date-parts":[[2024,12,9]]},"reference":[{"key":"2025022408454648200_bib1","doi-asserted-by":"publisher","first-page":"387","DOI":"10.1172\/JCI107774","article-title":"The hypercalciurias. 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