Objective: The objective of the study was to investigate the associations of sedentary time, physical activity, and cardiorespiratory fitness with skeletal muscle glucose uptake (GU).
Methods: Sedentary time and physical activity were measured with accelerometers and VO2 max with cycle ergometry in 44 sedentary adults with metabolic syndrome. Thigh muscle GU was determined with [18 F]FDG-PET imaging.
Results: Sedentary time (β = -0.374), standing (β = 0.376), steps (β = 0.351), and VO2 max (β = 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.
Conclusion: Body composition is a more important determinant of muscle GU in this population than sedentary time, physical activity, or fitness.
Keywords: insulin resistance; physical activity; positron emission tomography; sedentary behavior; skeletal muscle.
© 2022 The Authors. Scandinavian Journal of Medicine & Science In Sports published by John Wiley & Sons Ltd.