Adipose Tissue Infiltration of Skeletal Muscle in Children with Cerebral Palsy

Objective To determine whether children with quadriplegic cerebral palsy (QCP) have a greater adipose tissue (AT) infiltration of skeletal muscle than typically developing children (12/group and 5-14 years). Study design Cross-sectional area (CSA) of AT and muscle in the midthigh were assessed with magnetic resonance imaging. Physical activity was assessed with an activity monitor. Results Children with QCP had 2.3-fold higher intermuscular AT CSA and 51% lower muscle CSA in the midthigh than control subjects. Midthigh intermuscular, subfascial, and subcutaneous AT CSA adjusted for midthigh muscle CSA were higher in children with QCP (all P < .05). Moreover, the proportion of intermuscular AT CSA and subfascial AT CSA relative to subcutaneous AT CSA in the midthigh were 2.5-fold and 1.8-fold higher in children with QCP than control subjects (all P < .05). Children with QCP also had 70% fewer physical activity counts, which was inversely related to intermuscular AT CSA (r = −0.76) and subfascial AT CSA (r = −0.63) adjusted for muscle CSA in the midthigh of children with QCP (both P < 0.05), but not in control subjects. Conclusion Children with QCP have a greater AT infiltration of skeletal muscle than typically developing children, which is related to their low level of physical activity.