This review lays particular emphasis on diabetes mellitus-related osteoporosis (DOP) and estrogen deficiency-induced osteoporosis (EDOP), discussing bone remodeling between osteoclastogenesis and osteoblast differentiation regulated by key signaling pathways, including the RANKL/RANK/OPG, Wnt/β-catenin, BMP-Smad, Hedgehog, and inflammatory cytokine networks. Here, TNFRSF11A is linked to osteoporosis.