An overview of selected papers related to bone published in 2017 is provided.;PURPOSE: ;This paper accompanies a lecture at the 2018 Belgian Bone Club annual Clinical Update Symposium held in Brussels on January 20th, discussing the best papers (in the opinion of the author) published in the previous year.;METHODS: ;A PubMed search using the keyword "bone" and articles published in 2017.;RESULTS: ;Hot topics include screening for osteoporosis, novel anabolic drugs such as romosozumab and abaloparatide for osteoporosis and rare metabolic bone diseases, as well as long-term efficacy of denosumab and possible risk of multiple vertebral fractures following its discontinuation. Other selected articles cover effectiveness of bisphosphonates and changes in mineralization after long-term use, new guidelines for glucocorticoid- and aromatase inhibitor-induced osteoporosis, increasing use of high-dose vitamin D supplements despite lack of evidence for their widespread high-dose use, and cardiovascular safety concerns surrounding the use of calcium supplements. Other topics discussed are effects of diabetes on bone health, reciprocal crosstalk between bone cells and adipose tissue, and resistance exercise training to prevent bone loss and sarcopenia.

INTRODUCTION: ;Intermittent parathyroid hormone (PTH) administration, acting through multiple signaling pathways, exerts an osteoanabolic effect on the skeleton that surpasses the effect of other antiosteoporotic agents. However, its efficacy is limited by the coupling effect and relatively common adverse events. Thus, the development of more sophisticated PTH receptor analogs seems imperative.;AREAS COVERED: ;In this review, the authors summarize the role of PTH signaling pathway in bone remodeling. The authors also summarize investigational analogs targeting this pathway, which may be potential treatments for osteoporosis.;EXPERT OPINION: ;β-arrestins are multifunctional cytoplasmic molecules that are decisive for regulating intracellular PTH signaling. Recently, in preclinical studies, arrestin analogs have achieved the anabolic bone effect of PTH without an accompanying increase in bone resorption. However, it is not yet known whether these analogs have adverse effects and there are no clinical data for their efficacy to date. On the other hand, several molecules derived either from PTH and PTH-related protein (PTHrP) molecules have been developed. Alternative routes of PTH 1 - 34 delivery (oral, transdermal), the PTH analog ostabolin and the N-terminal PTHrP analogs PTHrP 1 - 36 and abaloparatide, have recently been or are currently being tested in clinical trials and are more likely to become available for use in the near future.

OBJECTIVE: ;To review the efficacy, safety, and economics of abaloparatide in the treatment of postmenopausal osteoporosis.;DATA SOURCES: ;PubMed (1966 to October 2017), Clinicaltrials.gov (October 2017), and Scopus (1970 to October 2017) were searched using abaloparatide, Tymlos, BA058, PTHrP 1-34 analog, and parathyroid hormone-related peptide 1-34 analog.;STUDY SELECTION AND DATA EXTRACTION: ;Human studies published in peer-reviewed publications in English were the primary sources for efficacy, safety, and economic data.;DATA SYNTHESIS: ;In the 2 randomized, published clinical studies of 24 weeks and 18 months duration, bone mineral density changes were higher for abaloparatide (lumbar spine, 6.7%-11.2%; femoral head, 3.1%-3.2%; total hip, 2.6%-4.2%) compared with placebo (lumbar spine, 0.6%-1.6%; femoral head, -0.4% to 0.8%; total hip, -0.1% to 0.4%; P < 0.05) and compared with teriparatide in the 24-week study (total hip 2.6% vs +0.5%, P < 0.05). New vertebral and nonvertebral fractures occurred in 0.6% and 2.7% of patients on abaloparatide compared with 4.2% and 4.7% on placebo in the 18-month study ( P < 0.05). Abaloparatide appears to have a somewhat higher risk for adverse effects, discontinuation as a result of adverse effects, and serious or severe adverse effects than teriparatide, but teriparatide has a higher risk for hypercalcemia.