Search

The efficacy and safety of parathyroid hormone (PTH) therapy for managing long-term hypoparathyroidism is being evaluated in ongoing clinical trials. We undertook a systematic review and meta-analysis of currently available randomized controlled trials to investigate the benefits and harms of PTH therapy and conventional therapy in the management of patients with chronic hypoparathyroidism. To identify eligible studies, published in English, we searched Embase, PubMed, and Cochrane CENTRAL from inception to May 2022. Two reviewers independently extracted data and assessed the risk of bias. We defined patients' important outcomes and used grading of recommendations, assessment, development, and evaluation (GRADE) to provide the structure for quantifying absolute effects and rating the quality of evidence. Seven randomized trials of 12 publications that enrolled a total of 386 patients proved eligible. The follow-up duration ranged from 1 to 36 months. Compared with conventional therapy, PTH therapy probably achieves a small improvement in physical health-related quality of life (mean difference [MD] 3.4, 95% confidence interval [CI] 1.5-5.3, minimally important difference 3.0, moderate certainty). PTH therapy results in more patients reaching 50% or greater reduction in the dose of active vitamin D and calcium (relative risk [RR] = 6.5, 95% CI 2.5-16.4, 385 more per 1000 patients, high certainty). PTH therapy may increase hypercalcemia (RR =2.4, 95% CI 1.2-5.04, low certainty). The findings may support the use of PTH therapy in patients with chronic hypoparathyroidism. Because of limitations of short duration and small sample size, evidence from randomized trials is limited regarding important benefits of PTH therapy compared with conventional therapy. Establishing such benefits will require further studies. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Previous reports have shown that bone mass and architecture will partially recover by remobilization (RM) in immobilization (IM)-induced osteopenia. The aim of this study was to test whether PTH can accelerate the recovery during RM from the IM-induced osteopenia. Six-month-old Sprague-Dawley female rats were divided into aging and IM groups. The right hindlimb of rats was immobilized against the abdomen by elastic bandages for 18 weeks, then groups of rats were further IM or RM for 2, 10 and 20 weeks and given 30 or 80 micrograms hPTH (1-38)/kg/d s.c. Secondary spongiosa of proximal tibial metaphyses (PTM) were studied. Immobilization reduced the trabecular area, number and thickness at the first 18 weeks post IM, then plateaued. Ten weeks of RM restored 40% trabecular bone from IM controls due to thickening of the trabeculae. However, the trabecular area was still -14% and -13% lower than that of aging controls at 10 and 20 weeks. Two weeks of 30 micrograms PTH/kg/d in IM rats restored the bone to aging control levels, two weeks of 30 micrograms PTH/kg/d in RM rats and of 80 micrograms PTH/kg/d in both RM and IM rats added extra bone. Extending the treatment to 10 and 20 weeks, the same amount of total bone was added to both IM and RM rats. These findings indicate PTH is a powerful agent that can accelerate the recovery and add extra bone to osteopenic cancellous bone in both IM and RM rats.

Purpose of review The prevention and treatment of osteoporosis has traditionally involved the use of antiresorptive therapies. The introduction of parathyroid hormone, an anabolic agent that enhances bone formation, has been accompanied by new treatment strategies. This article reviews combination and sequential therapy approaches with parathyroid hormone and antiresorptive agents to optimize efficacy outcomes. Recent findings The distinguishing features of the anabolic and antiresorptive therapies for the treatment of osteoporosis has led to the hypothesis that the appropriate use of both agents, either in sequence or in combination, may result in superior fracture protection compared with either anabolic or antiresorptive treatment alone. This enthusiasm has been tempered by the observations that the transition from daily bisphosphonate therapy may blunt the efficacy of teriparatide. By contrast, more recent studies suggest that once-weekly bisphosphonate therapy may provide a better option with parathyroid hormone either in combination or in sequence. These considerations are critical to understanding the benefits of sequential treatment (parathyroid hormone followed by an antiresorptive agent), which aims to maintain or build on the large gains in efficacy from short-term therapy with parathyroid hormone. Because patients may require an additional treatment course of parathyroid hormone in the future, the choice of antiresorptive agent should be carefully considered. In addition, more recent evidence suggests that the forms of parathyroid hormone may have important differences in action that influence combination and sequence outcomes. Summary Combination and sequential therapy with parathyroid hormone offers new options to maximize efficacy in patients at risk for osteoporotic fracture.