The chloride/phosphate ratio combined with alkaline phosphatase as a valuable predictive marker for primary hyperparathyroidism in Chinese individuals

Abstract

The chloride/phosphate ratio (Cl/PO4) has been suggested to have a role in primary hyperparathyroidism (PHPT), but the associations between Cl/PO4 combined with ALP level and PHPT has not been well-studied. Our aim was to investigate the predictive value of combination Cl/PO4 with ALP for PHPT. A cross-sectional retrospective analysis was conducted to examine 172 patients diagnosed with PHPT categorized into two groups: normocalcaemic primary hyperparathyroidism (NPHPT) group and hypercalcaemia PHPT group. We found that Cl/PO4 levels and ALP levels in the NPHPT and hypercalcaemia PHPT group were both significantly higher than normal controls. Cl/PO4 and ALP levels were an independent risk factor for PHPT. Cl/PO4 combined with ALP increased the receiver-operating characteristic curves (ROC-AUC) and the diagnostic value in NPHPT and hypercalcaemia PHPT group (0.913; 95% CI, 0.744–1.000 and 0.932; 95% CI, 0.897–0.966, respectively), specificity of 92.8% and sensitivity of 98%. In conclusion, combination Cl/PO4 with ALP might be a low-cost, simple, available predictive marker of PHPT in Chinese individuals, particularly Chinese remote region where the method used to measure PTH cannot be done. Moreover, due to serum calcium level in NPHPT, Cl/PO4 combined with ALP level measurement have great potential to predict significant occurrence of NPHPT.

The Utility of the Cl:PO4 Ratio in Patients With Variant Versions of Primary Hyperparathyroidism

“…Although it is considered general practice in most centers to examine both PTH and serum calcium, we mention this because diagnostic criteria vary according to institutions, and sometimes elevated PTH is solely considered for diagnosis. 14 Because of recent publications that reported a high sensitivity and specificity when using the Ca:PO4 ratio as an index to predict pHPT, 20,21 we also generated an ROC curve to see how the Ca:PO4 ratio would compare in our population. We reported an AUC of 0.813, which was still slightly inferior to the AUCs of calcium and ionized calcium but more sensitive than the Cl:PO4 ratio.…”

Severe, Symptomatic Hypocalcemia due to Denosumab Administration: Treatment and Clinical Course

“…Renal phosphorous excretion offsets the rising serum levels caused by PTH-driven bone resorption [16]. Patients with primary hyperparathyroidism exhibit mild reductions in serum phosphorous levels [17]. However, denosumab induces a PTH resistance specific to the bone, and the increasing PTH levels cause increased phosphorous excretion in the absence of osteoclastic liberation of bone phosphorous, overall leading to hypophosphatemia.…”

Diagnóstico del hiperparatiroidismo primario

“…La hipofosfatemia marginal (o niveles de fósforo plasmático en el límite bajo de la normalidad), junto con niveles de cloro en el rango alto de la normalidad, pueden resultar orientativos de HPP. En este sentido, un índice cloro/fosfato en sangre mayor de 33 presenta una sensibilidad >90% para el diagnóstico de HPP [13], que parece incrementarse aún más en presencia de niveles séricos elevados de fosfatasa alcalina total (>70 UI/L) [14]. [19].…”

“…• Determinación de la fosforemia y cloremia: para la orientación inicial hacia el HPP u otras formas de hipercalcemia (antes de disponer de los valores de PTH) [13,14]. • Determinación de la creatinina sérica y del filtrado glomerular: además de orientar hacia el diagnóstico diferencial en situaciones de hiperparatiroidismo, un filtrado glomerular <60 mL/min constituye uno de los marcadores para establecer la indicación quirúrgica.…”