Method: Perimenopausal rats (Natural aging model) were divided into 4 groups, Control (C), Exercise (E), low level laser (L) and Exercise + low level laser(E+L), with different interventions at every other day for 8-week. Exercise load: treadmill, -5°, 15m/min, and 30 min. The treatment of low level laser is designed as follows: semiconductor laser (810 nm，50 mW，11.94J/cm2 ), four irradiation point of femoral neck (anterior, posterior and medial and lateral; 30s per irradiation point). After 8-week, Estrogen, BMD, bone structure, bone biomechanical properties and sema3A protein were measured.
Analysis/Results: 1） Compared with the C group, the BMD of femur and whole body were increased in 3 intervention groups. E group had a remarked increase of local (femur) BMD, while the whole body BMD in E+L group raised significantly; 2) The number of trabecular bone increased in E, L and E+L group, meanwhile their combined effects was more significant. In addition, the bone biomechanical properties were improved in E+L group; 3) The level of Sema3A protein increased significantly in 3 treatment group, and that of in L and E+L group higher than E group.
Conclusions: Low-level laser therapy may be used as an effective intervention for perimenopausal women and other people with osteoporosis. Aerobic exercise combined with low lever laser will have a significantly beneficial effect on bone structure of both local and systemic body.