Efficacy and safety of recombinant human parathyroid hormone (1–34) are similar to those of alendronate in the treatment of postmenopausal osteoporosis

The study evaluates efficacy and safety of recombinant human parathyroid hormone (1–34) [rhPTH (1–34)] and alendronate (ALN) in the treatment of postmenopausal osteoporosis. Totally 65 postmenopausal women with osteoporosis were divided into 2 groups. PTH group received daily subcutaneous injection of rhPTH (1–34), and ALN group were treated orally with ALN per week. Bone mineral density (BMD) of lumbar spine (1–4), femoral neck, and total hip, serum levels of calcium, phosphorus, total cholesterol, triglyceride, alkaline phosphatase (ALP), N-terminal propeptide of type I collagen (PINP), and C-telopeptide of type I collagen (CTX) were tested before treatment and at week 24 and 48 after treatment. Serum levels of vascular endothelial growth factor (VEGF) and platelet-derived growth factor-BB (PDGF-BB) were measured before treatment and at week 48 after treatment. The rhPTH (1–34) increased BMD of lumbar spine (1–4), but decreased BMD of femoral neck and total hip at week 48 after treatment. By contrast, ALN enhanced BMD of lumbar spine (1–4) and femoral neck, but reduced BMD of total hip at week 48 after treatment. In PTH group, serum levels of PINP, ALP, and β-CTX were significantly elevated above baseline at week 24 and 48 after treatment. Treatment with ALN decreased levels of PINP, ALP, and β-CTX compared with baseline at week 24 and 48 after treatment. rhPTH (1–34) and ALN significantly decreased levels of PDGF-BB, but not levels of VEGF. rhPTH (1–34) increased levels of calcium, phosphorus and triglyceride, but decreased levels of total cholesterol. ALN increased levels of calcium and triglyceride, but reduced levels of phosphorus and total cholesterol. rhPTH (1–34) and ALN were safe in the treatment of postmenopausal osteoporosis. The study demonstrates that efficacy of rhPTH (1–34) on BMD of lumbar spine (1–4) is similar to that of alendronate in the treatment of postmenopausal osteoporosis. The effect of rhPTH (1–34) on BMD of femoral neck or total hip is weaker than that of ALN. In addition, rhPTH (1–34) increases BMD of lumbar spine (1–4) maybe by raising serum levels of VEGF, but reduces BMD of femoral neck and total hip maybe by decreasing serum levels of PDGF-BB.