Primer hiperparatiroidizmde klorür/fosfor ve klorür/magnezyum oranı

Abstract

Arka Plan: Giderek daha fazla tanınan bir endokrin bozukluk olan primer hiperparatiroidizm (PHPT), hiperkalsemik ve normokalsemik olmak üzere iki alt tipe ayrılmaktadır. Son dönem çalışmalarda, klorür/fosfor (Cl/P) ve klorür/magnezyum (Cl/Mg) oranları gibi biyokimyasal parametrelerin, PHPT’ye bağlı komplikasyonların tanısal değerlendirilmesi ve risk sınıflandırmasında yardımcı olabileceği öne sürülmektedir. Bu çalışmada, Cl/P ve Cl/Mg oranlarının PHPT alt tiplerini ayırt etmedeki tanısal ve öngörücü değerinin yanı sıra osteoporoz ve nefrolitiazis riskinin değerlendirilmesindeki potansiyel rolü araştırılmıştır. Yöntem: Bu retrospektif çalışmaya, 2019–2022 yılları arasında Ankara Bilkent Şehir Hastanesi’nde PHPT nedeniyle paratiroidektomi uygulanan 116 hasta dahil edilmiştir. Tüm hastalar, uluslararası kılavuzlara göre cerrahi endikasyonları karşılamaktaydı. Normokalsemik PHPT olguları, tekrarlayan normal kalsiyum düzeyleri ile birlikte sekonder nedenlerin dışlanmasıyla tanımlanmıştır. Hastaların preoperatif biyokimyasal parametreleri, görüntüleme bulguları ve komplikasyon profilleri analiz edilmiştir. Cl/P ve Cl/Mg oranları hesaplanarak Mann-Whitney U testi, Spearman korelasyon analizi ve ROC eğrisi analizi ile değerlendirilmiştir. Bulgular: Cl/P oranı, hiperkalsemik PHPT olgularında normokalsemik olgulara göre anlamlı düzeyde daha yüksek bulunmuştur (medyan 42,4 vs. 38,3; p = 0,0125) ve kemik mineral yoğunluğu ile pozitif korelasyon göstermiştir. Cl/P için belirlenen >43,6 eşik değeri, PHPT alt tiplerini ayırt etmede %80 özgüllük sağlamıştır (AUC: %64,1). Cl/Mg oranı alt tipler arasında anlamlı fark göstermemekle birlikte, nefrolitiazis riski ile anlamlı ilişki göstermiştir. ≤55 eşik değeri bu riski öngörmede %82,4 duyarlılık ve %66,7 özgüllük sunmuştur (AUC: %70,5; p = 0,0002). Sonuç: Cl/P ve Cl/Mg oranları, PHPT tanısal sürecini ve komplikasyon risk sınıflamasını destekleyen, düşük maliyetli ve kolay erişilebilir biyobelirteçler olarak umut vadetmektedir. Cl/P oranı, normokalsemik ve hiperkalsemik alt tiplerin ayrımında fayda sağlarken; Cl/Mg oranı, nefrolitiazis riski yüksek bireylerin belirlenmesinde etkili olmuştur. Bulgular, önceki çalışmalarla uyumludur ve bu oranların PHPT’nin klinik değerlendirme algoritmalarına entegre edilebileceğini düşündürmektedir.

Keywords

• Primer hiperparatiroidizm
• normokalsemik hiperparatiroidizm
• klorür/fosfor oranı
• klorür/magnezyum oranı
• paratiroidektomi

Clinical significance of chloride-to-phosphorus and chloride-to-magnesium ratios in primary hyperparathyroidism

Abstract

Aims: Primary hyperparathyroidism (PHPT), a well-recognized endocrine disorder, is subclassified into hypercalcemic and normocalcemic forms. Recent studies suggest that biochemical ratios such as the chloride-to-phosphorus (Cl/P) and chloride-to-magnesium (Cl/Mg) ratios may aid in the diagnostic evaluation and risk stratification of PHPT-related complications. This study aimed to investigate the diagnostic and predictive utility of the Cl/P and Cl/Mg ratios in differentiating PHPT subtypes and assessing the risk of osteoporosis and nephrolithiasis. Methods: This retrospective study included 116 patients who underwent parathyroidectomy for PHPT at Ankara Bilkent City Hospital between 2019 and 2022. All patients met surgical criteria based on international guidelines, and normocalcemic PHPT (N-PHPT) cases were defined by repeatedly normal calcium measurements and exclusion of secondary causes. Preoperative biochemical parameters, imaging findings, and complication profiles were analyzed. Cl/P and Cl/Mg ratios were calculated and evaluated using the Mann-Whitney U test, Spearman correlation, and receiver operating characteristic (ROC) analysis. Results: The Cl/P ratio was significantly higher in hypercalcemic PHPT than in normocalcemic patients (median 42.4 vs. 38.3, p=0.0125) and was positively associated with bone mineral density. A Cl/P threshold of >43.6 yielded 80.0% specificity in distinguishing PHPT subtypes [area under the curve (AUC): 64.1%]. The Cl/Mg ratio, although not differing between subtypes, was significantly associated with nephrolithiasis risk, with a cut-off value of ≤55 providing 82.4% sensitivity and 66.7% specificity (AUC: 70.5%, p<0.001). Conclusion: The Cl/P and Cl/Mg ratios show promise as low-cost, accessible biomarkers for enhancing diagnostic evaluation and risk stratification in PHPT. The Cl/P ratio demonstrated utility in distinguishing normocalcemic from hypercalcemic subtypes, while the Cl/Mg ratio effectively identified patients at increased risk of nephrolithiasis. These results are consistent with previous studies and support the potential integration of these indices into clinical assessment algorithms for PHPT.

Keywords

• Primary hyperparathyroidism
• normocalcemic hyperparathyroidism
• chloride-to-phosphorus ratio
• chloride-to-magnesium ratio
• parathyroidectomy

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