Abstract

Osteoporosis is one of the major problems facing older people of both sexes. This study was undertaken to investigate the synergistic effects of combination of statins and bisphosphonates in a glucocorticoid-induced osteoporosis (GIO) model. Thirty rats were divided into five groups; control group (I), GIO group (II) (given oral prednisolone, pred 30 mg/kg, per 2 days for 6 weeks), group III (treated by pred + risedronate, risedr 1mg/kg), group IV (treated by pred + simvastatin, sim 10 mg/kg) and group V (treated by pred +sim + risedr). Histological study of the femoral neck bone as well as biochemical assessments of serum alkaline phosphatase (ALP), carboxy-terminal collagen crosslinks (CTX), osteoprotegrin (OPG), leptin, Ca and phosphate were performed. The significant decreases in the trabecular bone thickness, area (p < 0.001), and the significant increase in bone marrow fat cells area (p < 0.001) detected in pred group, were corrected to be nearly similar to control values in groups III, IV and V. Groups that received sim showed better remodeled smoother surfaces bone trabeculae compared with other groups. Combination of sim + risedr shows a significant decrease of bone specific ALP in comparison to pred group (p < 0.05). Also, there was significant decrease of CTX in all treated groups in comparison to pred group (p < 0.05). On other hand, significant improvements of osteoprotegrin levels were noted in all treated groups (p < 0.05), however, there were insignificant changes in leptin levels among groups. In conclusion, addition of statins to bisphosphonate has qualitative rather than quantitative positive effect in experimental osteoporosis which might shorten the duration of therapy and increase efficacy when combined together.

Key words: Statins, bisphosphonates, glucocorticoids, osteoporosis.