Division of Endocrinology, Federal University of São Paulo, Brazil.
Bone. 2010 Jun;46(6):1516-21. doi: 10.1016/j.bone.2010.02.009. Epub 2010 Feb 10.
Glucocorticoids are an important cause of secondary osteoporosis in humans, which decreases bone quality and leads to fractures. Mechanical stimulation in the form of low-intensity and high-frequency vibration seems to be able to prevent bone loss and to stimulate bone formation. The objective of this study was to evaluate the effects of mechanical vibration on bone structure in rats treated with glucocorticoids. Thirty 3-month-old adult male Wistar rats were randomized to three groups: control (C), glucocorticoid (G), and glucocorticoid with vibration (GV). The G and GV groups received 3.5mg/kg/day of methylprednisolone 5 days/week for a duration of 9 weeks, and the C group received vehicle (saline solution) during the same period. The GV group was vibrated on a special platform for 30 min per day, 5 days per week during the experiment. The platform was set to provide a vertical acceleration of 1 G and a frequency of 60 Hz. Skeletal bone mass was evaluated by total body densitometry (DXA). Fracture load threshold, undecalcified bone histomorphometry, and bone volume were measured in tibias. Glucocorticoids induced a significantly lower weight gain (-9.7%) and reduced the bone mineral content (-9.2%) and trabecular number (-41.8%) and increased the trabecular spacing (+98.0%) in the G group, when compared to the control (C). Vibration (GV) was able to significantly preserve (29.2%) of the trabecular number and decrease the trabecular spacing (+26.6%) compared to the G group, although these parameters did not reach C group values. The fracture load threshold was not different between groups, but vibration significantly augmented the bone volume of the tibia by 21.4% in the GV group compared to the C group. Our study demonstrated that low-intensity and high-frequency mechanical vibration was able to partially inhibit the deleterious consequences of glucocorticoids on bone structure in rats.
糖皮质激素是人类继发性骨质疏松症的一个重要原因，它会降低骨质量并导致骨折。低强度、高频振动形式的机械刺激似乎能够防止骨丢失并刺激骨形成。本研究的目的是评估机械振动对接受糖皮质激素治疗的大鼠骨结构的影响。将 30 只 3 月龄成年雄性 Wistar 大鼠随机分为三组：对照组（C）、糖皮质激素组（G）和糖皮质激素加振动组（GV）。G 和 GV 组每周 5 天接受 3.5mg/kg/天的甲基强的松龙治疗 9 周，而 C 组在同一时期接受载体（生理盐水）。GV 组在实验期间每天接受 30 分钟的特殊平台振动，每周 5 天。平台设置提供 1G 的垂直加速度和 60Hz 的频率。全身骨密度（DXA）评估骨骼骨量。胫骨测定骨折负荷阈值、脱钙骨组织形态计量学和骨体积。与对照组（C）相比，糖皮质激素导致体重增加明显减少（-9.7%），骨矿物质含量（-9.2%）和小梁数量（-41.8%）减少，小梁间距增加（+98.0%）在 G 组。与 G 组相比，振动（GV）能够显著保留（29.2%）的小梁数量，并减少小梁间距（+26.6%），尽管这些参数未达到 C 组的值。骨折负荷阈值在各组之间没有差异，但与 C 组相比，GV 组胫骨骨体积增加了 21.4%。我们的研究表明，低强度、高频机械振动能够部分抑制糖皮质激素对大鼠骨结构的有害影响。
