Serum 25(OH) vitamin d level is associated with treatment outcome of whole-body vibration (WBV) for osteopenia in girls with adolescent idiopathic scoliosis (AIS)
© Lam et al; licensee BioMed Central Ltd. 2015
Published: 19 January 2015
AIS was associated with low bone mass which, apart from being an important health issue that could persist into adulthood, was also a significant prognostic factor for curve progression in AIS. We have performed a randomized controlled trial on WBV and reported its effect on increasing femoral neck areal bone mineral density (aBMD) mainly at the dominant leg but less obviously at the non-dominant side. The objective of this study was to evaluate the role of Vit-D in affecting the anabolic bone effect of WBV.
Material and methods
This was a study nested within a randomized controlled trial with enrolment of 122 AIS girls (15-25 years old) with BMD Z-scores < -1. They were randomly allocated to the Treatment or Control group. The Treatment group received WBV by standing on a low-magnitude high-frequency WBV platform 20 mins/day, 5 days/week (acceleration 0.3g, frequency 35 Hz). The Control group received observation alone. The study period was one year. aBMD at bilateral femoral necks was measured with Dual-Energy X-ray Absorptiometry at baseline and at 12-month. Serum 25(OH)Vit-D level by liquid chromatography tandem mass spectrometry was measured at 6-month within the treatment period.
The mean age was 17.8(SD=1.5) years old and mean Cobb angle was 29.4(SD=8.8) degrees. Subgroup analysis for those with serum 25(OH)Vit-D>40nmol/L revealed not only the positive effects of WBV were greater at both sides, treatment effects were explicitly also noted at the non-dominant leg. In addition, the positive correlation between serum 25(OH)Vit-D and percentage increase in femoral neck aBMD that was not present in the Control group was explicitly detectable in the Treatment group at the non-dominant leg(p=0.004).
The results strongly suggested the treatment effect of WBV could be enhanced through its synergistic factor interaction with Vit-D. The study carried significant clinical implication in that Vit-D insufficiency could affect negatively the treatment outcome of WBV for low bone mass in girls with AIS.
General Research Fund, Research Grants Council of Hong Kong (Project no: 467808 and 468809).
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.