| Objective To investigate the effect of GLP-1 receptor agonist liraglutide on bone metabolism markers in rats with glucocorticoid-induced osteoporosis (GIOP), including the effects on bone mass, bone tissue microstructure, bone biomechanics, and bone turnover markers. Methods Thirty male 8-week-old Sprague–Dawley rats were randomly divided into 3 groups: control, model, and liraglutide intervention group. The rats in model and intervention groups were intramuscularly injected with dexamethasone at 1 mg/kg (twice a week) to induce GIOP. Simultaneously, the rats in intervention group was subcutaneously injected with liraglutide at 200 ?g/kg daily. The control group was intramuscularly injected with an equal volume of 0.9% sodium chloride. The bilateral femurs and the fifth lumbar vertebrae were collected in 12 weeks to perform micro-computed tomography and bone biomechanical examinations. Also, tartrate-resistant acid phosphatase (TrACP), cross-linked carboxy-terminal telopeptide of type I collagen (CTX-I), alkaline phosphatase (ALP), and osteocalcin (OC) were tested. Results The bone mineral density (BMD) of the distal femurs and L5, TMD, BV/TV, Tb.Sp, Tb.Th, Tb.N, Conn.D, and bone biomechanical markers reduced significantly in the dexamethasone group compared with those in the control group. The bone resorption indicators TrACP and CTX-I increased, while the bone formation indicators ALP and OC decreased. After liraglutide treatment, BMD, bone microstructure, and bone biomechanical markers improved significantly. Moreover, TrACP and CTX-I decreased significantly, while ALP and OC increased compared with the model group. Conclusion Liraglutide antagonizes GIOP and relieves osteoporosis status. The protective mechanism might be related to a reduction in bone resorption and a promotion of bone formation. |