title: Real-time assessment of postprandial fat storage in liver and skeletal muscle in health and type 2 diabetes.
abstract: Liver and skeletal muscle triglyceride stores are elevated in type 2 diabetes and correlate with insulin resistance. As postprandial handling of dietary fat may be a critical determinant of tissue triglyceride levels, we quantified postprandial fat storage in normal and type 2 diabetes subjects. Healthy volunteers (n = 8) and diet-controlled type 2 diabetes subjects (n = 12) were studied using a novel 13C magnetic resonance spectroscopy protocol to measure the postprandial increment in liver and skeletal muscle triglyceride following ingestion of 13C-labeled fatty acids given with a standard mixed meal. The postprandial increment in hepatic triglyceride was rapid in both groups (peak increment controls: +7.3 +/- 1.5 mmol/l at 6 h, P = 0.002; peak increment diabetics: +10.8 +/- 3.4 mmol/l at 4 h, P = 0.009). The mean postprandial incremental AUC of hepatic 13C enrichment between the first and second meals (0 and 4 h) was significantly higher in the diabetes group (6.1 +/- 1.4 vs. 1.7 +/- 0.6 mmol x l(-1) x h(-1), P = 0.019). Postprandial increment in skeletal muscle triglyceride in the control group was small compared with the diabetic group, the mean 24-h postprandial incremental AUC being 0.2 +/- 0.3 vs. 1.7 +/- 0.4 mmol x l(-1) x h(-1) (P = 0.009). We conclude that the postprandial uptake of fatty acids by liver and skeletal muscle is increased in type 2 diabetes and may underlie the elevated tissue triglyceride stores and consequent insulin resistance.
authors.affiliation: School of Clinical Medical Sciences (Diabete)s Medical School, University of Newcastle, UK.
authors.forename: B
authors.initials: B
authors.lastname: Ravikumar
authors.forename: P E
authors.initials: PE
authors.lastname: Carey
authors.forename: J E M
authors.initials: JE
authors.lastname: Snaar
authors.forename: D K
authors.initials: DK
authors.lastname: Deelchand
authors.forename: D B
authors.initials: DB
authors.lastname: Cook
authors.forename: R D G
authors.initials: RD
authors.lastname: Neely
authors.forename: P T
authors.initials: PT
authors.lastname: English
authors.forename: M J
authors.initials: MJ
authors.lastname: Firbank
authors.forename: P G
authors.initials: PG
authors.lastname: Morris
authors.forename: R
authors.initials: R
authors.lastname: Taylor
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000097:blood; D019540:Area Under Curve; D001786:Blood Glucose / Q000378:metabolism; D002914:Chylomicrons; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000378:metabolism*; D004041:Dietary Fats / Q000378:metabolism; D005230:Fatty Acids, Nonesterified / Q000097:blood / Q000378:metabolism; D005260:Female; D005990:Glycerol / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D019344:Lactic Acid / Q000097:blood; D008074:Lipoproteins / Q000097:blood; D008099:Liver / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism*; D019518:Postprandial Period / Q000502:physiology; D014280:Triglycerides / Q000097:blood / Q000378:metabolism*
chemical_list: D001786:Blood Glucose; D002914:Chylomicrons; D004041:Dietary Fats; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D008074:Lipoproteins; D014280:Triglycerides; D019344:Lactic Acid; D005990:Glycerol; D020155:3-Hydroxybutyric Acid