TNFRSF11B and osteoporosis: Furthermore, the OPG/RANKL ratio was significant lower in the osteoporosis group than in the control group (SMD =  - 0.29; 95% CI - 0.57 to - 0.02; P value < 0.05), and the statistical heterogeneity was very low (Chi<sup>2</sup> = 0.20, P = 0.66, I<sup>2</sup> = 0%).<h4>Conclusions</h4>Our meta-analysis study supported OPG and RANKL were important modulatory factors of bone formation and resorption in bone turnover, respectively.