Madeo Bruno, De Vincentis Sara, Repaci Andrea, Altieri Paola, Vicennati Valentina, Kara Elda, Vescini Fabio, Amadori Pierluigi, Balestrieri Antonio, Pagotto Uberto, Simoni Manuela, Rochira Vincenzo
Unit of Endocrinology, Department of Medical Specialties, Azienda Ospedaliero-Universitaria di Modena, Ospedale Civile di Baggiovara, 41126, Modena, Italy.
Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41126, Modena, Italy.
Endocrine. 2020 Jun;68(3):679-687. doi: 10.1007/s12020-020-02276-7. Epub 2020 Mar 31.
The diagnosis of primary hyperparathyroidism (PHPT) and chronic hypoparathyroidism (HypoPT) is still challenging, especially in patients asymptomatic or with non-classical phenotypes and for physicians not skilled in calcium-phosphorous (Ca-P) disorders. The serum calcium/phosphorous (Ca/P) ratio has been proposed as accurate index to identify PHPT, while it has never been tested in HypoPT. The aim of this study is to investigate the diagnostic power of the serum Ca/P ratio in the diagnosis of primary parathyroid dysfunctions (both PHPT and HypoPT) in a large series of data.
A multicentric, retrospective, cross-sectional study (ClinicalTrials.gov: NCT03747029) was carried out including 432 PHPT patients and 217 HypoPT patients compared with 389 controls. Serum Ca, P, creatinine, parathyroid hormone and 25OH-vitamin D were collected. Serum Ca and P were expressed in mmol/L. Ca/P diagnostic performance was evaluated by receiver operating characteristic (ROC) curve, sensitivity, specificity and accuracy.
The Ca/P ratio was significantly higher in PHPT and lower in HypoPT patients than controls (p < 0.0001). At ROC curve analysis, the Ca/P ratio above 2.55 was defined to identify PHPT patients (sensitivity 85.7%, specificity 85.3%) and below 1.78 to identify HypoPT patients (sensitivity 88.2%, specificity 87.9%).
The Ca/P ratio is a highly accurate index to identify PHPT when Ca/P is above 2.55 and HypoPT when it is below 1.78. These results demonstrate the reliability of this index to rule in/out primary parathyroid dysfunctions and remark the importance of measuring serum P in clinical practice.
原发性甲状旁腺功能亢进症（PHPT）和慢性甲状旁腺功能减退症（HypoPT）的诊断仍然具有挑战性，尤其是对于无症状或具有非典型表型的患者以及不擅长钙磷（Ca-P）紊乱的医生而言。血清钙/磷（Ca/P）比值已被提议作为识别PHPT的准确指标，但从未在HypoPT中进行过测试。本研究的目的是在大量数据中研究血清Ca/P比值在原发性甲状旁腺功能障碍（PHPT和HypoPT）诊断中的诊断能力。
进行了一项多中心、回顾性、横断面研究（ClinicalTrials.gov：NCT03747029），纳入了432例PHPT患者和217例HypoPT患者，并与389例对照进行比较。收集了血清钙、磷、肌酐、甲状旁腺激素和25羟维生素D。血清钙和磷以mmol/L表示。通过受试者操作特征（ROC）曲线、敏感性、特异性和准确性评估Ca/P的诊断性能。
PHPT患者的Ca/P比值显著高于对照组，HypoPT患者的Ca/P比值显著低于对照组（p < 0.0001）。在ROC曲线分析中，Ca/P比值高于2.55被定义为识别PHPT患者（敏感性85.7%，特异性85.3%），低于1.78被定义为识别HypoPT患者（敏感性88.2%，特异性87.9%）。
当Ca/P高于2.55时，Ca/P比值是识别PHPT的高度准确指标；当Ca/P低于1.78时，是识别HypoPT的高度准确指标。这些结果证明了该指标在排除/纳入原发性甲状旁腺功能障碍方面的可靠性，并强调了在临床实践中测量血清磷的重要性。
