Effects of whole body vibration on bone mineral density in postmenopausal women: a systematic review and meta-analysis.

UNLABELLED: This systematic review and meta-analysis of randomized controlled trials (RCTs) identified significant effects of whole body vibration (WBV) on bone mineral density (BMD) of the lumbar spine (in the sensitivity analysis and seven subgroup analyses), femoral neck (in one subgroup analysis), and trochanter (four subgroup analyses) in postmenopausal women, but not other measurements of BMD. INTRODUCTION: Interventions using WBV training have been conducted in postmenopausal women, aimed at increasing BMD; however, the results are contradictory. Our objective is to conduct a systematic review and meta-analysis of RCTs examining WBV effect on BMD. METHODS: RCTs were considered eligible, with follow-up ≥6 months, which verified the effects of WBV on the BMD of postmenopausal women. The calculations of the meta-analysis were performed through the weighted mean difference between the WBV and control groups, or the WBV and combined training, through the absolute change between pre- and post-intervention in the areal bone mineral density (aBMD) or trabecular volumetric bone mineral density (vBMDt). RESULTS: Fifteen RCTs were included in the meta-analysis. No differences were observed in the primary analysis. WBV was found to improve aBMD compared with the control group, after exclusion of studies with low quality methodological (lumbar spine), when excluding the studies which combined WBV with medication or combined training (lumbar spine), with the use of low frequency and high magnitude (lumbar spine and trochanter), high frequency and low magnitude (lumbar spine), high cumulative dose and low magnitude (lumbar spine), low cumulative dose and high magnitude (lumbar spine and trochanter), with semi-flexed knee (lumbar spine, femoral neck, and trochanter), and side-alternating type of vibration (lumbar spine and trochanter). CONCLUSIONS: Despite WBV presenting potential to act as a coadjuvant in the prevention or treatment of osteoporosis, especially for aBMD of the lumbar spine, the ideal intervention is not yet clear. Our subgroup analyses helped to demonstrate the various factors which appear to influence the effects of WBV on BMD, contributing to clinical practice and the definition of protocols for future interventions.

Effect of low-level laser therapy on the gene expression of collagen and vascular endothelial growth factor in a culture of fibroblast cells in mice.

Low-level laser therapy treatment (LLLT) is widely used in rehabilitation clinics with the aim of accelerating the process of tissue repair; however, the molecular bases of the effect of LLLT have not been fully established. The aim of the present study was to evaluate the influence of the exposure of different doses of LLLT on the expression of collagen genes type I alpha 1 (COL1α1) and vascular endothelial growth factor (VEGF) in the fibroblast cells of mice (L929) cultivated in vitro. Fibroblast cells were irradiated with a Gallium-Arsenide laser (904 nm) every 24 h for 2 consecutive days, stored in an oven at 37 °C, with 5% CO2 and divided into 3 groups: G1-control group, G2-irradiated at 2 J/cm(2), and G3-irradiated at 3 J/cm(2). After irradiation, the total RNA was extracted and used in the complementary DNA (cDNA) synthesis. The gene expression was analyzed by real-time polymerase chain reaction. The cells irradiated in G2 exhibited a statistically significant growth of 1.78 in the expression of the messenger RNA (mRNA) of the COL1α1 gene (p = 0.036) in comparison with G1 and G3. As for the VEGF gene, an increase in expression was observed in the two irradiated groups in comparison with the control group. There was an increase in expression in G2 of 2.054 and G3 of 2.562 (p = 0.037) for this gene. LLLT (904 nm) had an influence on the expression of the genes COL1α1 (2 J/cm(2)) and VEGF (2 e 3 J/cm(2)) in a culture of the fibroblast cells of mice.

Laser 904 nm action on bone repair in rats with osteoporosis.

SUMMARY: The aim of the present study was to determine the action of AsGA laser irradiation on bone repair in the tibia of osteopenic rats. The animals were randomly divided into eight experimental groups according to the presence of ovarian hormone (sham group) or the absence of the hormone (OVX group), as well as being irradiated or non-irradiated. Low-level 904-nm laser (50 mJ/cm(2)) accelerated the repair process of osteopenic fractures, especially in the initial phase of bone regeneration. INTRODUCTION: The development of new techniques to speed the process of bone repair has provided significant advances in the treatment of fractures. Some attention recently focused on the effects of biostimulation on bone. METHODS: Forty-eight adult rats were randomly divided into eight experimental groups (six animals in each group) according to the presence of ovarian hormone (sham group) or absence of the hormone (ovariectomized (OVX) group) as well as being irradiated or non-irradiated. For the application of low-level laser therapy, the animals were anesthetized with one third of the dose sufficient to immobilize the animal and irradiated with AsGa laser (904 nm, 50 mJ/cm(2) for 2 s, point form and in contact). The control animals received the same type of manipulation as the irradiated animals, but with the laser turned off. Half of the animals were killed 7 days following the confection of the bone defect, and the other half were killed 21 days after the surgery. After complete demineralization, the tibias were cut cross-sectionally in the central region of the bone defect and embedded in paraffin blocks. The blocks were then cut in semi-seriated slices and stained with hematoxylin and eosin. RESULTS: There was new bone formation in the animals in the OVX group with laser treatment killed after 7 days (p < 0.001). The lowest percentage of bone formation was observed in the OVX without laser killed after 7 days (p > 0.05). All animals killed after 21 days exhibited linear closure of the lesion. CONCLUSION: Low-level 904-nm laser (50 mJ/cm(2)) accelerated the repair process of osteopenic fractures, especially in the initial phase of bone regeneration.