Associations of sedentary time, physical activity, and fitness with muscle glucose uptake in adults with metabolic syndrome

ObjectiveThe objective of the study was to investigate the associations of sedentary time, physical activity, and cardiorespiratory fitness with skeletal muscle glucose uptake (GU). MethodsSedentary time and physical activity were measured with accelerometers and VO(2)max with cycle ergometry in 44 sedentary adults with metabolic syndrome. Thigh muscle GU was determined with [F-18]FDG-PET imaging. ResultsSedentary time (beta = -0.374), standing (beta = 0.376), steps (beta = 0.351), and VO(2)max (beta = 0.598) were associated with muscle GU when adjusted for sex, age, and accelerometer wear time. Adjustment for body fat-% turned all associations non-significant. ConclusionBody composition is a more important determinant of muscle GU in this population than sedentary time, physical activity, or fitness.