Bone mineral content and physical activity in adolescents with cerebral palsy and their typically developing peers: a cross-sectional study.

Cerebral palsy (CP) is the most prevalent severe pediatric motor disability and often leads to compromised bone health due in part to limitations in functional mobility. While moderate-to-vigorous physical activity (MVPA) positively influences bone health, its relationship with bone parameters in adolescents with CP remains understudied. Our primary objective was to identify whether bone mineral content (BMC) and density (BMD) differ between ambulatory adolescents with CP and sex and maturity-status (years from peak height velocity) matched typically developing (TD) adolescents. Our secondary objective evaluated the association between MVPA and bone parameters. We conducted a secondary analysis on data from 64 adolescents (32 CP, 32 TD) and examined BMC and areal BMD (aBMD) using total body dual X-ray absorptiometry scans. MVPA was assessed using waist-worn accelerometers. Height-adjusted bone Z-scores accounted for differences in body size. Linear-mixed effects models revealed no significant differences in total body BMC (β: -0.34, 95% CI: -0.74 to 0.06, p = 0.097) or aBMD (-0.30, 95% CI: -0.76 to 0.17, p = 0.203) Z-scores between adolescents with CP and TD peers. MVPA was positively associated with height-adjusted BMC Z-scores, regardless of group (β: 0.01, 95% CI: 0.00 to 0.02, p = 0.023). These findings suggest that the greater functional ability of ambulatory adolescents with CP may play a protective role in bone accrual, and highlight the importance of physical activity for bone health in adolescents with and without CP.