Context: Osteogenesis imperfecta (OI) is associated with reduced muscle size, dynamic muscle function, and mobility.
Objective: To assess the effect of whole body vibration (WBV) on bone density and geometry, muscle size and function, mobility, and balance in children with OI.
Design: Randomized controlled pilot trial.
Setting: Tertiary pediatric research center.
Participants: Twenty-four children (5 to 16 years) with OI types 1, 4, and limited mobility [Child Health Assessment Questionnaire (CHAQ) score ≥ 0.13] recruited in sex- and pubertal stage-matched pairs. Incident fractures in two boys (WBV arm) led to exclusion of two prepubertal pairs.
Intervention: Five months of WBV training (3 × 3 minutes twice daily) or regular care.
Main outcome measures: Bone and muscle variables measured by dual-energy X-ray absorptiometry (spine, hip, total body) and peripheral quantitative computed tomography (tibia). Mobility assessed by 6-minute walk tests and CHAQ; dynamic muscle function by mechanography.
Results: All participants had reduced walking distances and muscle function (P < 0.001). Body mass index z score was associated with higher CHAQ scores (ρ + 0.552; P = 0.005) and lower walking and two-leg jumping performance (ρ - 0.405 to -0.654, P < 0.05). The WBV and control groups did not differ in the 5-month changes in bone. Total lean mass increased more in the WBV group [+1119 g (+224 to +1744)] compared with controls [+635 g (-951 to +1006)], P = 0.01, without improving mobility, muscle function, or balance.
Conclusions: The increase in lean mass without changes in muscle function or bone mass suggests reduced biomechanical responsiveness of the muscle-bone unit in children with OI.
Trial registration: ClinicalTrials.gov NCT03029312.
Copyright © 2017 Endocrine Society