Effect of aluminum hydroxide on serum phosphate and fibroblast growth factor 23 concentrations in young adult cats with surgically induced chronic kidney disease.

Abstract

OBJECTIVE: To describe serum fibroblast growth factor 23 (FGF-23) concentrations in young adult cats with remnant kidney model-induced chronic kidney disease (CKD) and to evaluate the effects of orally administered aluminum hydroxide (ALOH) on serum phosphate and FGF-23 concentrations in these cats. ANIMALS: 17 adult, purpose-bred cats with induced CKD and 13 healthy, age-matched cats. METHODS: A prospective, randomized study. Cats with induced CKD fed a wet renal diet received treatment with ALOH (90 mg/kg/d, PO) on days 0 to 42 and no treatment on days 43 to 84 (treatment group, n = 9) or no treatment on days 0 to 84 (control group, n = 8). Standard serum and urine biochemical analyses and several parameters reflective of calcium-phosphate balance, including serum parathyroid hormone and FGF-23 concentrations, were evaluated at baseline and various time points, including days 42 and 84. Age-matched, healthy, community-owned cats underwent similar evaluations at a single time point. Baseline data from CKD cats were compared to those of healthy cats. Longitudinal data from CKD cats were compared over time. RESULTS: Serum phosphate, total and ionized calcium, and FGF-23 concentrations were significantly higher in CKD cats at baseline relative to healthy cats (all P &#x2264; .009). Serum phosphate concentration did not change significantly over time in either CKD group; however, FGF-23 concentrations significantly increased over time in the control group (P < .02) but not the treatment group (P = .059). CLINICAL RELEVANCE: Aluminum hydroxide did not reduce serum phosphate or FGF-23 concentrations in this small study of cats with induced CKD chronically eating a phosphate-restricted diet.