Establishing a Reference Interval for Fibroblast Growth Factor (FGF)-23 in Cats

Area of Science:

• Veterinary Medicine
• Endocrinology
• Biochemistry

Background:

• Fibroblast growth factor-23 (FGF-23) is a key phosphaturic hormone.
• Elevated FGF-23 is linked to chronic kidney disease (CKD) progression in multiple species.
• Limited data exists on FGF-23 reference intervals (RIs) in cats.

Purpose of the Study:

• Establish RIs for FGF-23 in a large cohort of healthy cats.
• Investigate potential correlations between FGF-23 levels and feline age or sex.
• Provide a crucial benchmark for feline kidney health assessment.

Main Methods:

• Included 118 clinically healthy cats with normal bloodwork and chemistry.
• Excluded cats with concurrent diseases, suspected CKD, or on renal diets.
• Measured FGF-23 using an ELISA kit and calculated RIs with specialized software.

Main Results:

• Established a reference interval for FGF-23 in cats: 85.8 to 387.0 pg/mL.
• The 90% confidence interval for FGF-23 ranged from 40.5-103.9 pg/mL (lower limit) to 354.6-425.0 pg/mL (upper limit).
• No statistically significant correlations were found between FGF-23 concentrations and age (p=0.081) or sex (p=0.191).

Conclusions:

• The established FGF-23 RIs provide a vital diagnostic tool for feline veterinary medicine.
• FGF-23 levels in healthy cats are independent of age and sex.
• These findings align with previous studies using similar assays, reinforcing the established RIs.