Fibroblast growth factor 23 (FGF-23) is an independent monitor of the progression of chronic kidney disease (CKD) in human medicine, and FGF-23 may have value as a biomarker in feline CKD. We evaluated the relationship between serum FGF-23 and CKD stages, and the effect of age on FGF-23 in normal cats. We measured FGF-23 and intact parathyroid hormone (iPTH) concentrations by ELISA, with intra- and inter-assay CVs ≤ 15%. The percentage recovery of FGF-23 and iPTH remained stable for up to 7 d in samples stored at −20°C and −80°C. We measured FGF-23 in 304 cats, among which 196 were diagnosed with CKD. The 108 clinically healthy cats were divided into 5 subgroups based on growth stage (0–2 y, 3–6 y, 7–10 y, 11–14 y, ≥ 15 y). No statistical difference was found in FGF-23 among age groups (p = 0.15) or by sex in healthy subjects. Using the International Renal Interest Society guideline, 34 cats were defined as CKD stage 1, 74 stage 2, 51 stage 3, and 37 stage 4. FGF-23 was higher in cats in all CKD stages than in controls. Higher serum phosphorus was observed in stage 3 (p = 0.04) and 4 (p < 0.01) compared to controls. iPTH increased as CKD progressed. Pearson analysis indicated a positive linear relationship between FGF-23 and iPTH (control: r = 0.70, p < 0.01; CKD: r = 0.46, p = 0.02). FGF-23 may be a useful biomarker of feline CKD and may precede hyperphosphatemia in advanced feline CKD.

成纤维细胞生长因子 23 (FGF-23) 是人类医学中慢性肾脏病 (CKD) 进展的独立监测器，FGF-23 可能具有作为猫 CKD 的生物标志物的价值。我们评估了血清 FGF-23 和 CKD 分期之间的关系，以及年龄对正常猫 FGF-23 的影响。我们通过 ELISA 测量了 FGF-23 和完整的甲状旁腺激素 (iPTH) 浓度，测定内和测定间 CV ≤ 15%。在 -20°C 和 -80°C 下储存的样品中，FGF-23 和 iPTH 的回收百分比保持稳定长达 7 天。我们测量了 304 只猫的 FGF-23，其中 196 只被诊断患有 CKD。108 只临床健康的猫根据生长阶段分为 5 个亚组（0-2 岁、3-6 岁、7-10 岁、11-14 岁、≥15 岁）。FGF-23 年龄组间差异无统计学意义（p= 0.15) 或健康受试者的性别。使用国际肾脏利益协会指南，34 只猫被定义为 CKD 1 期、74 只猫 2 期、51 只 3 期和 37 只 4 期猫。所有 CKD 阶段猫的 FGF-23 均高于对照组。与对照组相比，在第 3 阶段（ p = 0.04）和第 4 阶段（p < 0.01）观察到更高的血清磷。iPTH 随着 CKD 的进展而增加。Pearson 分析表明 FGF-23 和 iPTH 之间呈正线性关系（对照：r = 0.70，p < 0.01；CKD：r = 0.46，p = 0.02）。FGF-23 可能是猫 CKD 的有用生物标志物，并且可能先于晚期猫 CKD 的高磷血症。