Bone density in premenopausal women and men under 50 years of age with cerebral palsy

Objective: To determine bone mineral density (BMD) z scores in adults with cerebral palsy (CP), an understudied population.

Design: Cross-sectional.

Setting: Medical facility.

Participants: Adults (N=48; mean age, 34.3±5.8y; range, 25-46y) with CP.

Interventions: Not applicable.

Main outcome measures: BMD z scores at the lumbar spine and hip using dual-energy x-ray absorptiometry, Gross Motor Function Classification System (GMFCS), body mass index (BMI), and ambulatory status.

Results: Mean BMD z scores were -1.40 for the lumbar spine, -1.36 for the total hip, and -1.02 for the femoral neck. The z scores were significantly lower for the nonambulatory group at all 3 sites (P<.05). Significant differences were found among GMFCS levels for the lumbar spine and total hip z scores (P<.05). For the lumbar spine, the mean z scores for level V (the lowest mobility level) were significantly lower than the mean for levels I/II (P=.001), III (P=.002), and IV (P=.013). For the total hip, the mean z scores for level V were significantly lower than the mean for levels I/II (P=.045). A significant positive relationship between the z scores and age was found for the lumbar spine (Spearman ρ=.40, P=.005). Significant positive relationships between BMI and z scores were found for all sites (P<.05).

Conclusions: This study contributes to the sparse literature about bone health in adults with CP. In contrast with pediatric data, z scores did not decrease as a function of age in this adult cohort. This information is important for clinicians considering treatment options for this population.