Elisa Le Roux¹, Sophie Hogan-Lamarre, Marie Lepitre, Guillermo Sanchez-Delgado, Frédérique Frisch, Gabriel Richard, Christophe Noll, Warner Mampuya, Serge Phoenix, Brigitte Guérin, Éric E. Turcotte, Joris Hoeks, Patrick Schrauwen, André C. Carpentier, Denis P. Blondin¹
¹CRCHUS and Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada.
Background: Exercise training reduces hepatic fat content in individuals with overweight, with or without type 2 diabetes or metabolic dysfunction-associated steatotic liver disease. However, some studies reported increased liver fat content after acute exercise. The mechanisms remain unclear, particularly whether this reflects increased non-esterified fatty acids (NEFA) uptake and/or reduced hepatic oxidation and triglyceride secretion. This study assessed the acute effects of high-intensity interval exercise on liver fat content and organ-specific FA fluxes in prediabetes.
Methods: Fifteen individuals with prediabetes (defined by at least one Diabetes Canada criteria or oral glucose insulin sensitivity ≤360ml/kg/min) were included (4 men, 11 women; mean age 58 [SD 8] years, weight 81.6 [15.5] kg, BMI 30.1 [4.4] kg/m²) in this ongoing study. Participants underwent two postprandial metabolic assessments: at baseline and 18–24h after an acute exercise bout. Hepatic fat fraction was assessed by MRI. Dynamic positron emission tomography/computed tomography with intravenous [¹¹C]-palmitate was used to evaluate organ-specific adipose tissue-derived NEFA fluxes 60min after liquid meal ingestion.
Results: Preliminary results indicate that a single exercise bout did not show significant changes in hepatic fat content (13.5 [7.7] vs 12.5 [6.7] %, P=0.207) or NEFA fluxes in liver, skeletal muscle, myocardium, kidney and adipose tissue. However, Spearman correlation analysis suggest moderate-to-strong negative associations between changes in liver fat fraction and changes in liver and myocardium FA oxidation (r=–0.71, P=0.058; r=–0.83, P=0.015), adipose tissue and kidney FA esterification (r=–0.75, P=0.066; r=–0.74, P=0.046) and myocardium FA uptake (r=–0.69, P=0.069).
Conclusion: Although no average changes were observed, increased liver fat content after a single exercise bout may be associated with reduced FA oxidation, uptake and esterification in lean organs and adipose tissue in individuals with prediabetes.