Impaired postprandial fibroblast growth factor (FGF)-19 response in patients with stage 5 chronic kidney diseases is ameliorated following antioxidative therapy

Abstract

While dysmetabolism is common in patients with chronic kidney disease (CKD) and associated with mortality, the mechanisms mediating these changes are unclear. New data implicate fibroblast growth factor (FGF)-19 as a possible entero-hepatic modulator of lipid metabolism. Using samples previously gathered as part of a randomized placebo-controlled study of antioxidative therapy for postprandial dysmetabolism, we investigated short-term (4 h) postprandial changes in circulating FGF-19 (ELISA) and the relationship to metabolic markers in six haemodialysis (HD) patients and nine matched healthy subjects (HS), with each participant assessed on four separate occasions. The postprandial FGF-19 response was blunted in patients [maximum change +34.63 (0.24-186) pg/mL] versus controls [maximum change +150.3 (31.2-378.7) pg/mL; P < 0.0001], and the area under the curve (AUC; pg × min × mL(-1)) was also significantly lower 18 019 (12 513-44 387) versus 38 517 (19 775-72 816; P < 0.01). In patients, we found univariate correlations between AUC FGF-19 with AUC C-peptide (rho = 0.71; P = 0.001), AUC insulin (rho = 0.63; P = 0.001), but not with AUCs for triglycerides (TG) or glucose. Finally, treatment with the antioxidative compounds N-acetyl cysteine or MP865, but not with placebo, was associated with higher plasma FGF-19 (NAC and MP865 coefficients -0.28 and -0.23, P < 0.05, respectively). In advanced CKD, the postprandial FGF-19 response appears to be blunted, with partial normalization following antioxidative treatments. A blunted FGF-19 response was associated with impaired insulin and C-peptide signalling.