PTH and osteoporosis: PTH, teriparatide, induces differentiation of pre-osteoblasts into osteoblasts, stimulates osteoblasts to form new bone, decreases osteoblast apoptosis, and directly promotes bone formation with an increase in the rates of both bone remodeling and modeling; it restores the structure of trabecular bone and increases cortical thickness and diameter in osteoporosis [42].