Effects of novel multi‐nodal micro‐vibration at multiple frequencies on bone turnover markers and bone strengthen in ovariectomized rats

Abstract

Osteoporosis is a bone disease characterized by low bone mass and structural deterioration. Whole body vibration (WBV) has been shown to have anti-osteoporotic effect. Current WBV devices use a fixed vibration frequency and displacement level. We developed a novel WBV device that simultaneously delivers multi-nodal micro-vibration displacements (1-4 mm) at multiple frequencies (20-130 Hz) (MVMF). The aim of this study was to test if MVMF technology prevents osteoporosis in ovariectomized (OVX) rats. Twenty three-month-old female Sprague Dawley rats were ovariectomized to induce osteoporosis, and another twenty rats underwent sham operation (SHAM). Two weeks after surgery, half of the rats in each group were treated with MVMF for 30 min/day, 3 day/week; the other half was untreated. After 12 weeks of treatment, rats were sacrificed and their blood and femur were harvested. Serum bone turnover markers were measured by enzyme-linked immunosorbent assay. The strength and stiffness of femur were measured by three-point bending. A 12-week treatment with MVMF had a tendency to increase maximal load of femur in both SHAM and OVX groups, although no statistical significance was found. Ovariectomy caused a significant increase in serum levels of osteocalcin and alkaline phosphatase (ALP), two bone formation markers, and tartrate-resistant acid phosphatase (TRAP) 5b, a bone resorption marker. Treatment with MVMF caused a significant decrease of osteocalcin, ALP, and TRAP 5b levels in OVX rats. The data suggests that the novel MVMF technology prevents OVX-induced increase in bone turnover, which has a potential to increase bone mass and strength in osteoporosis.