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Errol B. Marliss, M.D., FRCPC Professor Director, McGill Nutrition & Food Science Centre |
Research:
Clinical studies on:
- Whole-body protein metabolism in obesity, diabetes and aging.
- Regulation of glucose turnover in exercise in normal and diabetic persons.
The insufficient insulin action in diabetes affects not only glucose and fat, but also protein metabolism, in proportion to the magnitude of hyperglycemia. In collaboration with Drs. Réjeanne Gougeon and José Morais, we use stable isotopic methods (15N-glycine and 13C-leucine) to estimate protein turnover in aging an in Type 2 diabetic subjects during weight-maintaining and reducing diets, with varying levels of glycemic control. Correlations between the magnitude of alterations in glucose vs protein metabolism are made during hyperinsulinemic and euaminoacidemic clamp studies. Studies are performed in the RVH Clinical Investigation Unit. Insulin and glucagon usually regulate hepatic glucose production during exercise. Intense exercise at greater than 80% of maximum oxygen consumption is an exception, in which the major regulators appear to be catecholamines. We are testing this hypothesis by infusion of cathecholamines during exercise of lesser intensity, and use of alpha - and - beta adrenergic blocking agents. Glucose turnover is measured using labeled glucose. We have begun testing the hypothesis that prior intense exercise will inhibit the normal counterregulatory response to subsequent hypoglycemia, and the reverse, This has implications especially for Type 1 diabetes.
Selected Publications:
Gougeon, R., Styhler, K., Morais, J.A., Jones, P.J.H. and Marliss, E.B. Effects of oral hypoglycemic agents and diet on protein metabolism in Type 2 diabetes. Diabetes Care 23: 1-8, 2000.
Marliss, E.B., Kreisman, S.H., Manzon, A., Halter, J.B., Vranic, M. and Nessim S.J. Gender differences in glucoregulatory responses to intense exercise. J. Appl. Physiol. 88: 457-466, 2000.
Kreisman, S.H., Ah Mew, N., Arsenault, M., Nessim, S.J., Halter, J.B., Vranic, M. and Marliss, E.B. Epinephrine infusion during moderate intensity exercise increases glucose production and uptake. Am J Physiol: Endo & Metab 278: E949-957, 2000.
Kreisman, S.H., Ah Mew, N., Halter, J.B., Vranic, M. and Marliss, E.B. Norepinephrine infusion during moderate intensity exercise increases glucose production and uptake. J Clin Endocrinol Metab 86: 2118-2124, 2001.
Marliss, E.B. and Vranic, M. Intense exercise has unique effects on both insulin release and its role in glucoregulation: Implications for Diabetes. Diabetes 51: S271-S283.