Sophie Hogan-Lamarre1, Marie Lepitre, Elisa Le Roux, Guillermo Sanchez-Delgado, Frédérique Frisch, Gabriel Richard, Christophe Noll, Warner Mampuya, Serge Phoenix, Mélanie Fortin, Lucie Bouffard, Joris Hoeks, Patrick Schrauwen, Brigitte Guérin, Éric E. Turcotte, André C. Carpentier, Denis P. Blondin1.
1CRCHUS and Faculty of Medicine and Health Sciences, Université de Sherbrooke, QC, Canada.
Sophie.hogan-lamarre@usherbooke.ca
Background: Early disturbances in the storage of dietary fatty acids (DFA) within adipose tissue is believed to be a key mechanism linking obesity to the onset of insulin resistance, leading to an increased flux of fatty acids towards lean organs. Exercise is known to improve peripheral insulin sensitivity, but its effects on organ-specific DFA flux remains unclear. Here, we investigated the acute and chronic effects of high-intensity interval training (HIIT) on postprandial DFA metabolism in women and men with prediabetes.
Methods: 20 women and 5 men (mean age 59 [SD 8] years, weight 84.7 [15.2] kg, BMI 31,0 [5.1] kg/m2) with prediabetes (defined by at least one Diabetes Canada criteria or an oral glucose sensitivity index ≤360 ml/kg/min) participated in three postprandial metabolic protocols: (1)before, (2)18-24h after a single session and (3)48-72h after the last of 36 sessions of HIIT on an bicycle. Participants ingested a standard liquid meal containing the long-chain fatty acid positron emission tomography tracer [18F]-FTHA. Whole-body PET scans were taken 6h after meal consumption to quantify tissue distribution of DFA.
Results: Neither a single bout nor exercise training affected the retention of [18F]-FTHA in the intestines, heart, liver, skeletal muscle and adipose tissue depots (visceral and subcutaneous). This, despite an increase in VO2peak of 1.94 ml/kg/min (95%CI: 0.66 to 3.22ml/kg/min, P=0.0037) and maximum power output of 18 W (95%CI: 10 to 27W, P=0.0006) after 12 weeks of exercise.
Conclusion: Our preliminary results show no changes in the handling of DFA in response to HIIT. We expect that the time of day in which participants are performing their exercise bouts contributes significantly to the exercise-induced changes in metabolic responses and will be examined at the termination of the study.