Background and aims: The purpose of this study was to determine the relationship between whole body energy metabolism measured as oxygen consumption (VO2) and local muscle activity measured by positron emission tomography (PET) and [18F]fluorodeoxyglucose (FDG).
Methods: Ten community- dwelling older women (73-83 yrs) had FDG PET and VO2 measured while walking at a comfortable speed.
Results: A significant positive correlation was found between VO2 and FDG uptake in the biceps femoris (r=0.83), gluteus minimus (r=0.67), gluteus medius (r=0.77) and pelvis section muscles (r=0.76). The subjects who showed high FDG uptake in the hip muscle group had significantly higher VO2 while walking, compared with subjects without high FDG uptake in the hip muscles.
Conclusions: These results indicate that FDG PET provides an index which reflects whole body energy metabolism during walking, and revealed that excess muscle activity in the hip muscles during walking plays a key role in increasing VO2 in older adults.