Parathyroid Hormone Plus Alendronate in Osteoporosis: A Meta-Analysis of Randomized Controlled Trials

Parathyroid hormone (PTH) increases both bone formation (BMD) and bone resorption, whereas alendronate reduces bone resorption. It is possible that the combination therapy will enhance their effects on BMD. Therefore, we conducted this meta-analysis to evaluate the efficacy of the combination therapy in osteoporosis.

A comprehensive literature search of Pubmed, Embase, and Web of Science was conducted to identify relative studies. The outcomes included the mean percent increases in BMD of lumbar spine, femoral neck, total hip, and distal radius. A fixed-effects model or random-effects was used to pool the estimates according to the heterogeneity.

Six RCTs with a total number of 833 patients were included in this meta-analysis. The pooled estimates showed that, the combination therapy resulted in a higher mean percent change of increased BMD in distal radius (WMD = 2.45, 95%CI: 1.58, 3.31; 0.000), but not in lumbar spine (WMD = -0.83, 95%CI: -3.48, 1.81; p = .538), femoral neck (WMD = -0.99, 95%CI: -2.04, 0.07; p = .068), and total hip (WMD = -0.06, 95%CI: -0.93, 0.81; p = .892). Subgroup analysis revealed that among the patients in the combination therapy group, greater increases in the spine BMD were observed when the PTH was administered with a dosage of 20 μg (WMD = 2.33, 95%CI: 1.24, 3.43; p = .000), or the treatment duration lasted more than 12 months (WMD = 2.23, 95%CI: 1.00, 3.47; p = .000), or the combination therapy was used in osteoporosis women (WMD = 1.58, 95%CI: 0.63, 2.53; p = .001).

Our findings indicated that combination therapy in the treatment of osteoporosis, reduced the ability of PTH therapy to increase the BMD at the lumbar spine, femoral neck, and total hip.