Item – Theses Canada

OCLC number
Link(s) to full text
LAC copy
LAC copy
Riddell, Michael Charles,1967-
Effects of glucose ingestion during prolonged exercise in adolescents with and without insulin-dependent diabetes mellitus.
Ph. D. -- McMaster University, 2000
Ottawa : National Library of Canada = Bibliothèque nationale du Canada, [2002]
3 microfiches.
Includes bibliographical references.
This research was conducted to examine the influence of exogenous glucose (GLUexo) on the metabolic responses to exercise in adolescents with and without IDDM. In chapter 2, the influence of GLU exo on limiting hypoglycemia during exercise in adolescents with IDDM was investigated. We found that 60-min moderate exercise decreased blood glucose levels by 67 ± 3%, which could be attenuated to a 23 ± 7% decrease by GLUexo intake matched with total CHO utilization. The study presented in chapter 3 examined the rating of perceived exertion (RPE) during 60-min exercise performed with and without GLUexo in adolescents with IDDM and non-diabetic controls. For exercise performed at the same relative intensity, RPE was 2-3 points higher in the boys with IDDM compared with controls (P < 0.05). Although GLUexo attenuated the drop in glycemia during exercise, it was not associated with a change in RPE response in the boys with IDDM. The third study presented in chapter 4 examined the metabolic responses to 60min exercise with and without GLUexo enriched with 13C-labelled glucose in adolescents with and without IDDM. During exercise with water intake, total CHO and fat oxidation was similar between groups and contributed to ~75% and 25% to the total energy provision, respectively. During exercise with GLUexo, despite plasma insulin and gycemic levels that were 3-fold higher in the IDDM group, GLUexo oxidation, as measured by the ratio of 13CO2/ 12CO2 in expired gas, contributed to less of the overall energy provision in the boys with IDDM (9.0 ± 1.0%), compared with controls (12.4 ± 0.5%) (P < 0.05). In chapter 5, the metabolic responses to 2hrs exercise performed with and without GLUexo were investigated in non-diabetic adolescents. Compared with water, GLUexo increased total CHO oxidation by 20% and decreased fat oxidation by 45%. In addition, GLUexo oxidation contributed to ~25% of the total energy provision and spared endogenous CHO by ~16%. Plasma insulin levels decreased during exercise with water intake but remained at pre-exercise levels with GLUexo. The decrease in insulin levels with water paralleled increases in plasma free fatty acids and glycerol levels, while GLUexo attenuated these changes.