graduate student National Taiwan University Taipei City, Taipei, Taiwan (Republic of China)
Abstract:
Background: Elevated plasma fibroblast growth factor-23 (FGF23) in cats with chronic kidney disease (CKD) has emerged as a prognostic biomarker. Whether increased urinary FGF23 (uFGF23) is associated with either renal diseases or the outcome is unknown.
Objectives: To evaluate uFGF23 in cats with renal diseases and its relationship with negative outcomes.
Methods: Case-control study. Cats with International Renal Interest Society Stage 1&2 and Stage 3&4 CKD were enrolled in the early, and late CKD groups, respectively, whereas ACKD was defined as an increase of >1 mg/dL and >20% baseline in serum creatinine concentration within 30 days. Urinary FGF23 was measured using commercial ELISA and expressed as uFGF23-to-creatinine ratio (uFGF23/cr).
Results: A significantly elevated uFGF23/cr (median [IQR]: 11.98 [7.09-19.15] pg/mg) was observed in the ACKD group compared to the control group (0.91 [0.66-1.01] pg/mg), early CKD group (2.57 [1.09-4.09] pg/mg), and late CKD group (7.01 [5.77-8.06] pg/mg, all P < .001). The odds of 30-day mortality increased with an elevated uFGF23/cr (odds ratio= 1.57, 95% confidence interval= 1.02-2.41, P = .04) after adjusting for the CKD stage. Cats with ACKD in the high uFGF23/cr (cutoff = 17.9 pg/mg) group were associated with higher 30-day mortality (6/6, 100%, versus 1/12, 8.3%, P < .001), and had higher BUN (116 [112-160] versus 60 [40.3-106.3] mg/dL, P = .037).
Conclusions and Clinical Importance: Urinary FGF23 is elevated with a decline in renal function and could be a potential biomarker to predict the prognosis of ACKD.
