FGF-23在慢性腎衰竭導致之續發性副甲狀腺機能亢進中所扮演的角色

The Role of FGF-23 in Secondary Hyperparathyroidism in Chronic Kidney Disease

江銘彥(Ming-Yan Jiang) ； 黃志強(Jyh-Chang Hwang) ； 呂宜樺(Yi-Hua Lu) ； 吳佳純(Chia-Chun Wu) ； 簡志強(Chih-Chiang Chien) ； 甘偉志(Wei-Chih Kan) ； 王憲奕(Hsien-Yi Wang) ； 鄭高珍(Kuo-Chen Cheng)

《內科學誌》 23卷3期 (2012/06) Pp. 199-205

https://doi.org/10.6314/JIMT.2012.23(3).07

摘要

慢性腎臟病患者由於磷酸鹽（phosphate）堆積、血鈣（calcium）下降、以及活性維生素D3（calcitriol）減少，因此促進副甲狀腺荷爾蒙（parathyroid hormone）的製造及分泌增加，導致續發性副甲狀腺機能亢進（secondary hyperparathyroidism），進而引起腎性骨病變（renal osteodystrophy）。過去認為影響體內鈣磷平衡的因素主要是副甲狀腺荷爾蒙及活性維生素D3，fibroblast growth factor-23（FGF-23）的發現使我們對於慢性腎臟病患者體內的鈣磷平衡有更深入的了解。FGF-23是由成骨細胞（osteoblast）所分泌，當體內磷酸鹽堆積、副甲狀腺荷爾蒙上升、或是活性維生素D3增加時，會促進FGF-23的分泌。FGF-23會增加磷酸鹽由尿液排泄、並抑制活性維生素D3的合成，並且由於活性維生素D3的合成降低，因此會使副甲狀腺荷爾蒙製造及分泌增加，副甲狀腺荷爾蒙增加則會促進FGF-23的分泌。近幾年來由於FGF-23的發現，開啟了許多實驗性的及臨床上的研究，也讓我們知道骨骼、腎臟、及副甲狀腺之間，存在許多回饋路徑，而且會彼此影響，共同作用去調節鈣磷的代謝。本篇綜論主要是要探討FGF-23的生理功能，以及它在鈣磷平衡及續發性副甲狀腺機能亢進中所扮演的角色。

關鍵字

Fibroblast growth factor 23 ； 慢性腎臟病 ； 續發性副甲狀腺機能亢進 ； 腎性骨病變

並列摘要

Patients with chronic kidney disease (CKD) develop secondary hyperparathyroidism, which is a consequence of phosphorus retention, decline in serum calcium levels, and decreased calcitriol production. Increased parathyroid hormone (PTH) synthesis and secretion result in renal osteodystrophy. PTH and vitamin D were previously considered the major factors regulating calcium and phosphate homeostasis. The discovery of FGF-23 has provided a new insight into the disorder of calcium and phosphate metabolism in CKD. FGF-23 is secreted by osteoblasts in response to a phosphorus load, high calcitriol levels and an increased PTH levels. FGF-23 causes both an increase in urinary phosphorus excretion and a reduction in calcitriol synthesis. The reduction in calcitriol levels caused by FGF-23 leads to an increase in PTH production and secretion. High PTH level would result in increased FGF-23 levels. The identification of FGF-23 opens a new field for clinical and experimental research in phosphate homeostasis. There are several feedback loops, involving parathyroid glands, bone, and kidney, regulating serum phosphate concentration. We will review the physiologic function of FGF-23 and its role in calcium and phosphate homeostasis and secondary hyperparathyroidism.

並列關鍵字

Fibroblast growth factor 23 ； Chronic kidney disease ； Secondary hyperparathyroidism ； Renal osteodystrophy