Response to the American College of Physicians Osteoporosis Guideline, 2017 Update

Remote-controllable bone-targeted delivery of estradiol for the treatment of ovariectomy-induced osteoporosis in rats

BACKGROUND

Osteoporosis (OP) is a systemic skeletal disease marked by bone mass reduction and bone tissue destruction. Hormone replacement therapy is an effective treatment for post-menopausal OP, but estrogen has poor tissue selectivity and severe side effects.

RESULTS

In this study, we constructed a poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs)-based drug delivery system to co-load 17β estradiol (E₂) and iron oxide (Fe₃O₄) together, modified with alendronate (AL) to achieve bone targeting and realize a magnetically remote-controllable drug release. The NPs were fabricated through the emulsion solvent diffusion method. The particle size was approximately 200 nm while the encapsulation efficiency of E₂ was 58.34 ± 9.21%. The NPs were found to be spherical with a homogenous distribution of particle size. The NPs showed good stability, good biocompatibility, high encapsulation ability of E₂ and excellent magnetic properties. The NPs could be effectively taken up by Raw 264.7 cells and were effective in enriching drugs in bone tissue. The co-loaded NPs exposed to an external magnetic field ameliorated OVX-induced bone loss through increased BV/TV, decreased Tb.N and Tb.Sp, improved bone strength, increased PINP and OC, and downregulated CTX and TRAP-5b. The haematological index and histopathological analyses displayed the NPs had less side effects on non-skeletal tissues.

CONCLUSIONS

This study presented a remote-controlled release system based on bone-targeted multifunctional NPs and a new potential approach to bone-targeted therapy of OP.

Hormone therapy for postmenopausal osteoporosis management

Menopausal hormone therapy (MHT) has been used for prevention and treatment of postmenopausal osteoporosis for several decades. However, public concerns were raised over the safety of MHT after the initial report was published in 2002 by the Women's Health Initiative. We conducted a historical review on this subject, primarily focusing on level I evidence from randomized controlled trials, systematic reviews and meta-analyses, and summarized high-quality evidence on the efficacy and safety of MHT in management of postmenopausal osteoporosis. Clinical issues were also discussed on MHT initiation, identification of treatment candidates and treatment duration, as well as discontinuation of MHT.

Isoflavones and bone health in perimenopausal and postmenopausal women

PURPOSE OF REVIEW

Isoflavones exert estrogenic activity distinct from estrogen, they have the potential to treat diseases and symptoms related to estrogen deficiency with minimal side effects and risks. Isoflavone supplementation, in general, is shown to exert beneficial effects against estrogen-deficient bone loss in women, however, some clinical trials still produce conflicting findings. The purpose of this review is to highlight and summarize the most recent and up-to-date research in the field and to bring attention to factors that play a major role in the outcomes of clinical trials that investigate phytoestrogens. Here, we also discuss the latest and most relevant data regarding the clinical safety of these substances.

RECENT FINDINGS

Isoflavones are naturally occurring secondary metabolites found in the Fabacaea plant family. Clinical data from isoflavone interventions support that aglycones (abundant in fermented products) exert enhanced beneficial effects against estrogen-deficient bone loss in women compared with isoflavone glycosides. Studies that employ methods to determine isoflavone content and form of treatments are more likely detect beneficial effects on bone. EFSA have confirmed the safety of isoflavones for women in the most comprehensive report to date.

SUMMARY

Isoflavone aglycones exert greater effects against bone loss than glycosides. Isoflavones show promise as a first-line prophylactic/treatment for bone loss in women.

Review of the guideline of the American College of Physicians on the treatment of osteoporosis

This review, endorsed by the International Osteoporosis Foundation and the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases, summarizes several failings of the recent guidelines of the American College of Physicians (ACP) on the treatment of low bone density or osteoporosis to prevent fractures.

INTRODUCTION

The ACP recently issued guidelines for the treatment of low bone density or osteoporosis to prevent fractures.

METHODS

Literature review and critical review of the ACP guidelines.

RESULTS

The guideline is lacking in scope due to the endorsement of treatment based on T-scores rather than fracture risk assessment and in failure to adequately consider anabolic therapies.

CONCLUSIONS

The ACP guideline appears outdated.