Mechanistic model of fuel selection in the muscle.
Fuel selection in human muscle is key to explaining insulin resistance. In obesity and type 2 diabetes mellitus, there is an increased content of lipid within and around muscle fibers. Changes in muscle fuel partitioning of lipid, between oxidation and storage of fat, contribute to the accumulation of intramuscular triglycerides and to the pathogenesis of both obesity and type 2 diabetes mellitus. A mathematical model of the aggregated metabolism in skeletal muscle was developed and the effects of fuel selection for lean and obese individuals under fasting conditions, insulin-stimulated conditions, and oscillating insulin conditions were examined. Model results were complementary to prior observations that elevated lipid oxidation during insulin-stimulated conditions is correlated with insulin resistance. The model also adequately simulated metabolic inflexibility between fat and glucose oxidation in the obese individual. A novel sensitivity analysis indicated the strong interaction effects of parameters of glucose and lipid oxidation pathways on the variables of each pathway.
Institut de Recherche et de Développement. 32, avenue Henri Varagnat, 93143 Bondy cedex, France.
P
P
de Beaudrap
G
G
Witten
G
G
Biltz
E
E
Perrier
D001786:Blood Glucose / Q000378:metabolism; D003198:Computer Simulation; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism; D005215:Fasting; D005227:Fatty Acids / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance; D050356:Lipid Metabolism; D008954:Models, Biological; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000378:metabolism*; D009765:Obesity / Q000378:metabolism*; D014280:Triglycerides / Q000378:metabolism
D001786:Blood Glucose; D005227:Fatty Acids; D007328:Insulin; D014280:Triglycerides