title: Decrease in circulating fibroblast growth factor 21 after an oral fat load is related to postprandial triglyceride-rich lipoproteins and liver fat.
abstract: BACKGROUND
  Elevated levels of circulating fibroblast growth factor 21 (FGF21) are commonly encountered in type 2 diabetes, dyslipidemia, and non-alcoholic fatty liver disease, all of which share exaggerated postprandial lipemia as a common proatherogenic feature. How FGF21 responds to an oral fat load in man is unknown.
  
  
  METHODS
  We measured liver fat contents and subcutaneous and visceral fat volumes in 47 healthy subjects, who also underwent an oral fat load with measurements of plasma FGF21 and free fatty acid (FFA). Triglyceride (TG), apolipoprotein B-48 (apoB-48), and apoB-100 concentrations were measured in triglyceride-rich lipoprotein (TRL) fractions.
  
  
  RESULTS
  When compared with fasting levels, the concentration of FGF21 decreased significantly at 4 h (P < 0.05) and tended to return to fasting levels at 8 h after an oral fat load. Fasting and postprandial FGF21 correlated significantly with liver fat as well as with TRLs in the chylomicron and especially in very low-density lipoprotein 1 (VLDL1) and VLDL2 fractions representing remnant particles, but not with FFA. Subjects with increased liver fat (>5%, n = 12) showed impaired suppression of FGF21 at 4 h (P < 0.05) and at 8 h (P=0.01) and demonstrated higher postprandial TG area under the curve in plasma and TRL fractions (P ≤ 0.032) compared with those with normal liver fat (≤ 5%, n = 35).
  
  
  CONCLUSIONS
  We observed a significant decrease of FGF21 concentration after an oral fat load. Fasting and postprandial FGF21 levels were closely related to large VLDL and remnants, but not to plasma FFA. Our pilot findings suggest that the postprandial accumulation of TRL remnants and liver fat may modulate postprandial FGF21 levels.
authors.affiliation: Division of Cardiology Division of Endocrinology, Department of Medicine, Helsinki University Central Hospital, University of Helsinki, PO Box 700, FIN-00029 Helsinki, Finland. niina.matikainen@hus.fi
authors.forename: Niina
authors.initials: N
authors.lastname: Matikainen
authors.forename: Marja-Riitta
authors.initials: MR
authors.lastname: Taskinen
authors.forename: Sanna
authors.initials: S
authors.lastname: Stennabb
authors.forename: Nina
authors.initials: N
authors.lastname: Lundbom
authors.forename: Antti
authors.initials: A
authors.lastname: Hakkarainen
authors.forename: Kirsi
authors.initials: K
authors.lastname: Vaaralahti
authors.forename: Taneli
authors.initials: T
authors.lastname: Raivio
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D053299:Apolipoprotein B-100 / Q000097:blood; D053283:Apolipoprotein B-48 / Q000097:blood; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D004041:Dietary Fats / Q000008:administration & dosage*; D005230:Fatty Acids, Nonesterified / Q000097:blood*; D005234:Fatty Liver / Q000097:blood* / Q000175:diagnosis; D005260:Female; D005346:Fibroblast Growth Factors / Q000037:antagonists & inhibitors* / Q000097:blood*; D006801:Humans; D008079:Lipoproteins, VLDL / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D019518:Postprandial Period / Q000502:physiology*; D014280:Triglycerides / Q000097:blood; D055815:Young Adult
chemical_list: D053299:Apolipoprotein B-100; D053283:Apolipoprotein B-48; D015415:Biomarkers; D004041:Dietary Fats; D005230:Fatty Acids, Nonesterified; D008079:Lipoproteins, VLDL; D014280:Triglycerides; C414620:fibroblast growth factor 21; D005346:Fibroblast Growth Factors