We investigated the effects and optimal treatment frequency of pulsed electromagnetic fields (PEMFs) on postmenopausal osteoporosis (PMO). A comparison was performed with the cyclical alendronate and a course of PEMFs in the treatment for postmenopausal osteoporosis on bone mineral density (BMD), pain intensity and balance function. There was no significant difference between the two groups on mean percentage changes from baseline of BMD within 24 weeks after random treatments (P≥0.05). However, at the ends of 48 weeks and 72 weeks, the BMD of the PEMFs group were significantly lower than that of the alendronate group (P<0.05). No significant difference was detected between the two groups with regard to treatment effects on Visual Analogue Scale score, the Timed Up & Go Test and Berg Balance Scale score. Compared with cyclical alendronate, a course of PEMFs was as effective as alendronate in treating PMO for at least 24weeks. So its optimal treatment frequency for PMO may be one course per six months.
This study is to investigate the inhibitory effect of different concentrations of zoledronic acid on the activity of osteoclasts, to obtain characteristics on inhibitory effect and to find the lowest effective concentration of zoledronic acid. Marrow cells of C57 mice (6 weeks) were cultured in vitro. Osteoclasts were induced by single nuclear cells. According to the concentration of zoledronic acid, we set up the experimental group with five different concentrations, i.e. 1×10–8 mol/L, 1×10–7 mol/L, 1×10–6 mol/L, 1×10–5 mol/L, and 1×10–4 mol/L. The control group did not contain any bisphosphonate. By tartrate resistant acid phosphatase staining, the number of multinuclear cells, cells through the filter and bone resorption lacune were counted. Five days after the cultivation, the number of multinuclear cells in the experimental group decreased with the increase of concentration of zoledronic acid. Inhibition on the formation of osteoclasts in vitro was effective at 1×10–6 mol/L. At the concentration of 1×10–5 mol/L, the effect of inhibition on migration of osteoclast and bone resorption was more obvious. The effect was further enhanced at concentration of 1×10–4 mol/L. However, the concentration and inhibition curves were gradually mild. The inhibitory effect on different concentrations of zoledronic acid on the activity of osteoclasts was different. The inhibition effect was obvious at 1×10–6 mol/L. We should pay attention to administrate appropriate concentration of zoledronic acid in the clinical applications.