P.7.13 Whole body vibration training lowers serum creatine kinase levels in boys with Duchenne muscular dystrophy

Abstract

Whole body vibration training (WBVT) involves the use of a low-amplitude high-frequency vibrating platform to transmit mechanical energy. It has been proposed as a therapeutic strategy to increase bone mineral density in boys with Duchenne muscular dystrophy (DMD). The effects of WBVT on muscle enzymes and motor function have not been fully elucidated. The aim of this study was to explore the safety as well as potential effects of WBVT on muscle function. We performed baseline and serial assessments including serum creatine kinase (CK) measurements and timed function tests in two brothers aged 8 and 10 years old with genetically confirmed DMD. WBVT was delivered using a side-alternating vibration platform (Vibraflex) at a starting frequency of 7.5 Hz, increasing up to 20 Hz for a total of 5 min (2 min on, 1 min off, and 2 min on) three times a week for three months. The baseline serum CK of the 8 and 10 year old boys were 33,105 U/L and 14,984 U/L. One month after receiving WBVT, their CK dropped significantly, reaching a nadir of 7383 U/L and 536 U/L respectively during treatment. Aside from transient flushing and increased sweating, there were no other side effects. The 6-min walk distance (6MWD) for the older brother increased slightly from 404 m at baseline to 448 m at six weeks on WBVT, and then to 376 m two weeks post treatment. The 6MWD for the younger boy increased from a baseline of 354–447 m after WBVT. Their overall North Star Ambulatory Assessment scores were unchanged. WBVT appears to be safe and well-tolerated in ambulatory boys with DMD. The reduction in serum CK as observed in these two brothers on otherwise stable treatment suggests a positive effect of brief high frequency vibration on muscle function. Additional longitudinal studies involving a larger cohort will help to determine the role of WBVT as a safe and potentially beneficial exercise strategy for boys with DMD.