Bone mineral density of the rat tibia under modeling of glucocorticoid-induced osteoporosis and the influence of whole body vibration: experimental stud

Abstract

The aim – investigate the effect of whole-body vibration with high-frequency on the mineral density of the tibia of rats treated with glucocorticoids.Material and methods. 54 adult male Wistar rats were randomized to three groups: control, experimental group I - rats treated with methylprednisolone and experimental group II - methylprednisolone with whole-body vibration. Rats of the two experimental groups received methylprednisolone at a dose of 3 mg/kg every other day for 24 weeks. Group II was subjected to a total vertical vibration (50 Hz, with a vibration acceleration of 0.3g) for 30 min per day, 5 days per week throughout the experiment. Mineral density was assessed by CT densitometry at 8-16-24 weeks of the study.Results. The most significant bone loss was observed in experimental group I at the 16th and 24th week of the experiment, which decreased by 18.6% and 20.8%, respectively, compared with the control group. In experimental group II, the bone density index did not statistically decrease at the 8th week of our study, but at the 16th week decreased by -16.3%; and on the 24th week by -23.5% according to the control group. The density of the cortical layer of bone tissue did not change statistically in the experimental groups in relation to the control group.Conclusions. Our study demonstrated that high-frequency mechanical oscillations could partially suppress the harmful effects of methylprednisolone on bone mineral density in rats. Because glucocorticoids are an important cause of secondary osteoporosis in humans, mechanical stimulation in the form of exercise and training can prevent bone loss and stimulate bone formation.