Links Between Hypertension and Osteoporosis: Benidipine Ameliorates Osteoporosis in Ovariectomized Hypertensive Rats Through Promotion of Osteoblast Proliferation and Inhibition of Osteoclast Differentiation

Recent studies have demonstrated that some antihypertensive drugs reduced the risk of bone fracture. Although calcium channel blockers (CCB) are used as first-line agents, there is no evidence that they prevent osteoporosis. In this study, we investigated the effects of 2 types of CCB, benidipine (L-/T-type CCB) and amlodipine (L-type CCB), on bone metabolism. In ovariectomized SHR, administration of benidipine resulted in a significant increase in the ratio of ALP to TRAP and a decrease in the number of osteoclasts in the tibia. Moreover, bone mineral density was significantly higher in the benidipine group compared with the amlodipine group, associated with a significant decrease in urinary deoxypyridinoline. In an in vitro study, benidipine promoted ALP expression and decreased receptor activator of NF-kB (RANK) ligand expression of human osteoblasts, indicating suppression of osteoclast differentiation. These pleiotropic effects of antihypertensive drugs such as benidipine might provide additional benefits in treating hypertensive postmenopausal women.