Exploratory Comparison of Cardiac Left and Right Ventricle and Skeletal Muscle Glucose Uptake After Exercise

PURPOSE: This study aimed to measure and compare postexercise glucose uptake (GU) in the left and right ventricular myocardium (LV and RV, respectively) and quadriceps femoris (QF) muscle. METHODS: Six recreationally active males (22 [2] y; VO2peak 54 [6] mL/kg/min; maximal power 350 [22] W) completed a 30-minute cycling bout. The protocol comprised 10 minutes at 100 W, a ramp to exhaustion (+25 W/min), 1 min passive recovery, then cycling at 75% VO2peak to 30 minute GU was quantified with 2-[18F]FDG PET. RESULTS: Postexercise GU in the LV myocardium (14.1 [5.1] μmol/100 g/min) was significantly higher (P < .01) than that in the RV (7.2 [3.2] μmol/100 g/min) or QF muscle (6.4 [1.9] μmol/100 g/min). GU in the LV and RV correlated strongly (r = .84, P = .039), whereas GU in these ventricles did not correlate with QF GU (P > .27). Circulating venous blood lactate concentration was 1.1 (0.5) mmol/L at rest and peaked at 10.4 (2.6) mmol/L postexercise. Peak lactate tended to correlate positively with GU, particularly in the RV (r = .93, P = .02) and LV (r = .87, P = .055) myocardium, and to a lesser extent in the QF muscle (r = .78, P = .12). CONCLUSION: These findings indicate that the LV myocardium consumes more glucose per unit mass than skeletal muscle after vigorous exercise, whereas the RV shows no such difference.