Context: Bile acids regulate lipid and carbohydrate metabolism by interaction with membrane or intracellular proteins including the nuclear farnesoid X receptor (FXR). Postprandial activation of ileal FXR leads to secretion of fibroblast growth factor 19 (FGF-19), a gut hormone that may be implicated in postprandial glucose metabolism.
Objective: To describe postprandial plasma concentrations of 12 individual bile acids and FGF-19 in patients with type 2 diabetes (T2D) and healthy controls.
Design and setting: Descriptive study, performed at the Center for Diabetes Research, Gentofte Hospital, Hellerup, Denmark.
Participants: Fifteen patients with T2D and 15 healthy matched controls with normal glucose tolerance.
Interventions: A 75-g oral glucose tolerance test and three isocaloric and isovolemic liquid meals with low, medium, and high fat content, respectively.
Main outcome measures: Bile acid and FGF-19 concentrations.
Results: Postprandial total bile acid concentrations increased with increasing meal fat content (P < .05), peaked after 1-2 hours, and were higher in T2D patients vs controls (oral glucose tolerance test, low and medium fat meals, P < .05; high fat meal, P = .30). Differences reflected mainly unconjugated and glycine-conjugated forms of deoxycholic acid (DCA) and to a lesser extent cholic acid (CA) and ursodeoxycholic acid (UDCA), whereas chenodeoxycholic acid (CDCA) concentrations were comparable in the two groups. FGF-19 concentrations tended to be lower in T2D patients vs controls, but differences were not statistically significant due to considerable variation.
Conclusion: Postprandial plasma patterns of bile acids with FXR agonistic properties (CDCA, DCA, and CA) and FXR antagonistic properties (UDCA) in T2D patients support the notion of a "T2D-bile acid-FGF-19" phenotype with possible pathophysiological implications.
Trial registration: ClinicalTrials.gov NCT01374594.