ECE2022 Poster Presentations Calcium and Bone (68 abstracts)
Application of Calcium to Phosphorus (Ca/P) ratio in the diagnosis of pseudohypoparathyroidism: Another piece in the puzzle of diagnosis of Ca-P metabolism disorders
Sara De Vincentis 1,2,3 , Giulia Brigante 1,2 , Giulia Del Sindaco 4,5 , Antonio Moretti 1 , Angela Pagnano 4,5 , Lucia Zirilli 2 , Vincenzo Rochira 1,2 , Manuela Simoni 1,2 , Giovanna Mantovani 4,5 & Bruno Madeo 2
1Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Modena, Italy; 2Unit of Endocrinology, Department of Medical Specialties, Azienda Ospedaliero-Universitaria Policlinico di Modena, Modena, Italy; 3Clinical and Experimental Medicine PhD Program, University of Modena and Reggio Emilia, Modena, Italy; 4Department of Clinical Sciences and Community Health, University of Milan, Milan, Milan, Italy; 5Endocrinology Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Milan, Italy
Introduction: The serum calcium/phosphorus (Ca/P) ratio has been proposed to identify patients with primary hyperparathyroidism and chronic hypoparathyroidism (HPT) from healthy subjects. However, other disorders of the Ca-P metabolism might present similar biochemical profile of HPT, such as pseudohypoparathyroidism (PHP), for which the use of Ca/P can be useful.
Aim: To test the performance of Ca/P ratio in the diagnosis of PHP in comparison to healthy subjects and to HPT patients for differential diagnosis.
Methods: A retrospective, observational study was carried out, including 60 PHP patients and 60 HPT patients compared to 120 controls. Serum Ca, P, creatinine, parathyroid hormone (PTH) and albumin, and creatinine were collected. Serum Ca and P were expressed in mg/dL. The diagnostic performance was evaluated by receiver operating characteristic (ROC) curve, sensitivity, specificity and accuracy.
Results: The Ca/P ratio was significantly lower in PHP and HPT patients, compared to controls (P<0.0001). At ROC curve analysis, the cut-off of 2.32 (1.78 if serum Ca and P measured in mmol/L) for Ca/P ratio was able to identify both PHP and HPT patients among the entire cohort (sensitivity and specificity: 76%). Selecting patients with Ca/P ratio below 2.32, no valid cut-off of Ca/P was found to discriminate PHP from HPT patients; in this case, serum PTH above 53.0 pg/mL was defined for the identification of PHP patients (sensitivity and specificity: 100%). The index (Ca/P x PTH) above 150 pg/mL identified PHP patients from controls (sensitivity 84.7%; specificity 87.4%), whereas (Ca/P x PTH) below 44 pg/mL identified HPT patients from controls (sensitivity 88.9%; specificity 90.8%).
Conclusions: This study further validates the serum Ca/P ratio below 2.32 (1.78 SI) as a highly accurate tool to identify PHP and HPT patients, but it is not reliable to differentiate these two conditions. The index (Ca/P x PTH) is excellent to specifically recognize PHP or HPT from healthy subjects. Thanks to its extraordinary simplicity and the favorable cost-effectiveness, serum Ca and P should be equally considered as first-line examinations to calculate their ratio that can be easily applied to screen/rule out disorders of Ca-P metabolism, especially in asymptomatic patients.
Article tools
My recent searches
My recently viewed abstracts
Authors
Endocrine Abstracts
ISSN 1470-3947 (print) | ISSN 1479-6848 (online)
© Bioscientifica 2024 |
Privacy policy |
Cookie settings
BiosciAbstracts
Bioscientifica Abstracts is the gateway to a series of products that provide a permanent, citable record of abstracts for biomedical and life science conferences.
Find out more