Low bone mass often observed in adults with cerebral palsy is likely a reflection of poor bone accrual in early childhood rather than rapid bone loss, implying that clinicians should take steps to optimize patient bone health at an early age, according to findings published in Clinical Endocrinology.
“As [cerebral palsy] life expectancy continues to improve, there is increasing recognition that a life span approach is needed to maintain bone health and function,” Anne Trinh, MD, a doctoral student in the department of medicine at Monash University in Melbourne, Australia, and colleagues wrote in the study background. “As these individuals age, many become dependent on assistive devices, and up to 75% of individuals lose their ability to mobilize. Preserving bone and muscle health to maintain mobility and independence is, therefore, critical.”
In a retrospective, longitudinal study, Trinh and colleagues assessed changes in areal bone mineral density during adolescence and young adulthood in 45 individuals with cerebral palsy, as well as the effect of ambulation, nutrition and hypogonadism on longitudinal changes in areal BMD. Participants underwent DXA scans for suspected low BMD between 2006 and 2018 (mean age at first DXA, 19 years; 57.8% male; 80% nonambulatory).
Within the cohort, mean baseline z scores were less than –2 at the lumbar spine, femoral neck, total hip and total body. The median increase in areal BMD for the cohort ranged from 1.2% to 1.9% per year; however, the median increase ranged from 4% to 8% per year among participants younger than 20 years (n = 12; mean age at initial DXA scan, 14 years). Z scores across all sites remained stable over time, according to researchers.
Reduced functional state, measured by the Gross Motor Function Classification System (GMFCS), had a small negative effect on areal BMD over time.
“It was surprising that functional status as measured by GMFCS or ambulation status did not have a greater effect, as cross-sectional studies in both children and adults with [cerebral palsy] have shown a consistent positive effect of ambulation on [areal] BMD,” the researchers wrote. “By excluding subjects < 10 years of age, we may not have captured the impact of ambulation on bone accrual given the onset of motor deficits in [cerebral palsy] at birth.”
The researchers noted that interventions during childhood, such as improving muscle strength and mobility, optimizing nutritional and hormonal status, and judicious use of bisphosphonates are likely key to achieving optimal adult bone health. – by Regina Schaffer
Disclosures: The authors report no relevant financial disclosures.