Effects of prior moderate exercise on exogenous and endogenous lipid metabolism and plasma factor VII activity.
Moderate exercise reduces postprandial triacylglycerol concentrations, which are a risk marker for coronary heart disease. The present study sought to determine the qualitative nature of exercise-induced changes in lipid metabolism and their association (if any) with changes in factor VII activation. Eleven normotriglyceridaemic men, aged 51.7+/-6.1 years (mean+/-S.D.), participated in two oral fat tolerance tests after different pre-conditions: control (no exercise), and exercise (90 min of brisk walking the day before). Venous blood samples were obtained in the fasted state and for 8 h after ingestion of a high-fat meal (1.32 g of fat, 1.36 g of carbohydrate, 0.30 g of protein and 10 mg of [1,1,1-(13)C] tripalmitin x kg(-1) body mass). Prior exercise reduced postprandial plasma triacylglycerol concentrations by 25+/-3% (mean+/-S.E.M.), with lower concentrations in the Svedberg flotation rate (Sf) 20--400 (very-low-density lipoprotein) fraction accounting for 79+/-10% of this reduction. There was no effect on plasma factor VII coagulant activity or on the concentration of the active form of factor VIIa. Prior exercise increased postprandial serum 3-hydroxybutyrate and plasma fatty acid concentrations, decreased serum postprandial insulin concentrations and increased exogenous (8 h (13)C breath excretion of 15.1+/-0.9% of ingested dose compared with 11.9+/-0.8%; P=0.00001) and endogenous postprandial fat oxidation. These data raise the possibility that reduced hepatic secretion of very-low-density lipoprotein plays a role in the attenuation of plasma triacylglycerol concentrations seen after exercise, although it is possible that increased triacylglycerol clearance also contributes to this effect.
Gill
J M
JM
Human Muscle Metabolism Research Group, Loughborough University, Loughborough, LE113TU, UK. j.gill@clinmed.gla.ac.uk
Frayn
K N
KN
Wootton
S A
SA
Miller
G J
GJ
Hardman
A E
AE
D000368:Aged; D002914:Chylomicrons / Q000097:blood; D004041:Dietary Fats / Q000378:metabolism; D004734:Energy Metabolism / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005167:Factor VII / Q000378:metabolism*; D005215:Fasting / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D019518:Postprandial Period / Q000502:physiology; D014280:Triglycerides / Q000097:blood*
D002914:Chylomicrons; D004041:Dietary Fats; D007328:Insulin; D014280:Triglycerides; D005167:Factor VII