Osteoporosis therapy: an example of putting evidence-based medicine into clinical practice

[Suitability of strontium ranelate in a health care management area after drug surveillance alerts]

OBJECTIVE

To analyse the impact of a strategy on the suitability of strontium ranelate, and its level of acceptance, after issuing recommendations based on drug surveillance alerts issued by the Spanish Medicines and Medical Devices Agency.

DESIGN

A prospective interventional study conducted from April 2012 to November 2014.

SETTING

South Seville Health Management Area.

PARTICIPANTS

Patients currently prescribed with strontium ranelate.

INTERVENTIONS

The study consisted of four phases linked to the issue of drug surveillance alerts on strontium ranelate by the Spanish Medicines and Medical Devices Agency, listed by patients and suitability recommendations.

MAIN MEASUREMENTS

Suitability of strontium ranelate treatment and the level of acceptance by physicians.

RESULTS

There was a reduction of 87.9% in prescriptions from the beginning of the study, with 182 patients included, until the review of the suitability of the drug began. The prescribing of strontium ranelate was unsuitable in 16 out of the 22 patients remaining; 11 of which were due not meeting the treatment criteria, 3 for not having had previous treatments with other drugs for the prevention of fractures, and 2 due to contraindications. The level of acceptance of the recommendations was 87.5%, leading to the stopping of strontium ranelate in 10 patients, and the changing to alendronate or alendronate/cholecalciferol in another four patients.

CONCLUSIONS

The number of patients prescribed strontium ranelate has decreased considerably. The interventions directed at reviewing the suitability of this treatment, based on the drug surveillance alerts, have been effective.

Osteogenic differentiation of placenta-derived multipotent cells in vitro

OBJECTIVE

Stem cells offer great potential for clinical therapeutic use because of their ability to rejuvenate and to differentiate into numerous types of cells. We isolated multipotent cells from the human term placenta that were capable of differentiation into cells of all three germ layers.

MATERIALS AND METHODS

We examined the ability of these placenta-derived multipotent cells (PDMCs) to differentiate into osteoblasts (OBs) or OB-like cells. The PDMCs were treated with osteogenic medium (OM) consisting of dexamethasone, β-glycerol phosphate, and ascorbic acid. At sequential time intervals (0 day, 3 days, 6 days, 9 days, and 12 days) we measured several parameters. These included alkaline phosphatase (ALP) activity, alizarin red staining (ARS) to measure calcium deposition, messenger RNA (mRNA) expressions of osteogenesis-related transcription factor (Cbfa1), and calcium coordination protein (osteocalcin). These variables were used as indicators of PDMC osteodifferentiation.

RESULTS

We showed that ALP activity in the early stage of differentiation and calcium deposition were both significantly increased in PDMCs after OM induction. Moreover, the Cbfa1 and osteocalcin gene expressions were upregulated. The results suggested that OM induced an osteodifferentiation potential in PDMCs.

CONCLUSION

PDMC-derived osteocytes provide a useful model to evaluate the mechanisms of key biomolecules and bioengineering processes.

Calcium homeostasis influences radiological fracture healing in postmenopausal women

INTRODUCTION

Recent studies suggest that calcium and 25-[OH]-cholecalciferol represent substantial co-factors in fracture healing. However, there still seems to be no sustainable consensus regarding the influence on fracture healing patterns. In this study, the influence of calcium and vitamin D levels on fracture callus formation was prospectively analysed using pQCT scan.

METHODS

94 postmenopausal females with distal radius fractures and consecutive surgery were included. Calcium, 25-[OH]-cholecalciferol, parathyroid hormone and bone-specific alkaline phosphatase levels were obtained prior surgical treatment and after 6 weeks. A pQCT scan was performed on both sites. Bone mineral density and fracture callus area were determined after detecting the outer border contour at a threshold of 280 mg/ccm. Patients received daily supplements of 1000 mg calcium and 880 IU 25-[OH]-cholecalciferol.

RESULTS

Mean 25-[OH]-cholecalciferol level was 19.61 ± 21.87 ng/ml, mean parathyroid hormone level was 52.6 ± 58.9 ng/l and mean Ca level was 2.23 ± 0.35 mmol/l. After 6 weeks of supplementation a significant increase of calcium (p < 0.001) and 25-[OH]-cholecalciferol (p < 0.001), and a significant decrease of parathyroid hormone (p < 0.001) levels were observed. Sixth week follow-up fracture callus area correlated significantly with postoperative normal range calcium levels on the fractured site (p = 0.006). Bone mineral density correlated with age (p < 0.001), but not with calcium and 25-[OH]-cholecalciferol levels after 6 weeks. All fractures presented timely adequate callus formation.

CONCLUSION

Calcium and parathyroid hormone serum levels influence fracture callus area interpreted as fracture callus formation patterns. Calcium levels within physiological range accounted for highest fracture callus area. Therefore, a balanced calcium homeostasis is required for appropriate callus formation.

Homocysteine level and risk of fracture: A meta-analysis and systematic review

AIMS

Previous studies have reported inconsistent findings regarding the association between elevated plasma Hcy levels and fracture risk. We investigated this association between homocysteine (Hcy) levels in patients with fracture and unaffected controls by conducting a meta-analysis and systematic review.

METHODS

We conducted a systematic literature search (up to April 2012) of the PubMed database and Embase. We selected observational studies that evaluated Hcy levels in subjects with fracture compared to unaffected controls. We also included randomized clinical trials (RCTs) on the effect of Hcy-lowering therapy in fracture patients. Criteria for inclusion were the assessment of baseline Hcy and risk of fracture as an outcome. The results were presented as relative risk (RR) and corresponding 95% confidence intervals (CI) comparing fracture patients to the control subjects or the highest Hcy quartile group to the lowest Hcy quartile group.

RESULTS

Nine studies with 14,863 participants were identified and analyzed. The pooled RR from a random effect model of participants with all fractures compared with the control subjects was 1.59 (95% CI 1.30-1.96). The pooled RR from a random model for hip fractures in the highest Hcy quartile group compared with the lowest Hcy quartile group was 1.67 (95% CI 1.17-2.38). The effect of Hcy-lowering therapy on fracture was tested in two clinical trials, but clinically important end points were not reported in a consistent way.

CONCLUSIONS

This meta-analysis and systematic review suggested that Hcy significantly increased the risk of fracture, and the increase was independent of risk factors.

[2011 Up-date of the consensus statement of the Spanish Society of Rheumatology on osteoporosis]

OBJECTIVE

Due to increasing improvement in the diagnosis, evaluation and management of osteoporosis and the development of new tools and drugs, the Spanish Society of Rheumatology (SER) has promoted the development of recommendations based on the best evidence available. These recommendations should be a reference to rheumatologists and other health professionals involved in the treatment of patients with osteoporosis.

METHODS

Recommendations were developed following a nominal group methodology and based on a systematic review. The level of evidence and degree of recommendation were classified according to the model proposed by the Center for Evidence Based Medicine at Oxford. The level of agreement was established through Delphi technique. Evidence from previous consensus and available clinical guidelines was used.

RESULTS

We have produced recommendations on diagnosis, evaluation and management of osteoporosis. These recommendations include the glucocorticoid-induced osteoporosis, premenopausal and male osteoporosis.

CONCLUSIONS

We present the SER recommendations related to the biologic therapy risk management.

Anti-fracture efficacy of risedronic acid in men: A meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVE

Male osteoporosis is an important public health issue and remains undertreated. We performed this meta-analysis to clarify the anti-fracture efficacy of risedronic acid in men.

METHODS

Randomized controlled trials (RCTs) in men receiving risedronic acid or placebo published between 1980 and September 2008 were searched for in MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials. Studies with a follow-up of at least 12 months and providing the incidence of fractures were considered for inclusion in the review. Two independent reviewers assessed the methodological quality of the included studies and performed data extraction. Analysis of pooled data was carried out using Revman 4.2 software.

RESULTS

Four RCTs met the inclusion criteria and permitted a pooled estimate of effectiveness. Relative risk with 95% confidence intervals for pooled effect under fixed effects model were: 0.31 (0.16, 0.60) for vertebral fractures and 0.40 (0.23, 0.70) for nonvertebral fractures, suggesting a 69% risk reduction of vertebral fractures and a 60% risk reduction of nonvertebral fracture with risedronic acid treatment in men.

CONCLUSION

The results of this meta-analysis show that risedronic acid treatment is associated with a reduced risk of fractures in men.

Alendronate/vitamin D3 70 mg/2800 IU with and without additional 2800 IU vitamin D3 for osteoporosis: results from the 24-week extension of a 15-week randomized, controlled trial

Although vitamin D supplementation is a fundamental part of osteoporosis treatment, many patients do not regularly take adequate amounts. A once-weekly (OW) alendronate (ALN) preparation that includes 2800 IU of vitamin D3 in a single combination tablet (ALN+D2800) is available for treating patients and ensuring intake of vitamin D that is consistent with existing guidelines. This randomized, double-blind study extension was conducted to evaluate the safety and tolerability of ALN+D2800 and ALN+D2800 plus an additional 2800 IU vitamin D3 single tablet supplement (ALN+D5600) administered for 24 weeks in men and postmenopausal women with osteoporosis previously treated OW for 15 weeks with either ALN or ALN+D2800. The primary endpoint was the proportion of participants who developed hypercalciuria (defined as a 24-hour urine calcium >300 mg in women or >350 mg in men and an increase of >25% versus randomization baseline) at week 39. The key secondary endpoint was the proportion of participants with vitamin D insufficiency (serum 25(OH)D <15 ng/mL [37.4 nmol/L]) at the end of the study. Hypercalciuria incidence (4.2% [ALN+D5600] vs. 2.8% [ALN+D2800]), did not differ between groups (p = 0.354). No participants developed hypercalcemia. Among the participants with vitamin D insufficiency at the week 0 baseline, the prevalence of insufficiency at the end of the study was reduced by 92% in the ALN+D5600 group and by 86% in the ALN+D2800 group. The incidences of clinical adverse experiences, including drug-related adverse experiences, were similar in both groups. In subjects previously treated with ALN+D2800 for 15 weeks, the addition of 2800 IU D3 for 24 weeks did not produce hypercalcemia nor increase the risk of hypercalciuria.

Anti-resorptives in the management of osteoporosis

Bone-active agents that decrease bone turnover (the anti-resorptive agents) have been, to date, the most thoroughly studied pharmacological agents for the management of osteoporosis in a variety of populations - postmenopausal, male, and glucocorticoid-induced osteoporosis - and have received both Food and Drug Administration (FDA) and Committee for Medicinal Products for Human Use (CHMP) as well as other worldwide registrations for the management of these conditions. While the mechanisms of action of 'anti-resorptives' as a class differ, their effect on increasing bone strength and reducing the risk of fragility fractures share common pathways: an increase in bone mineral content, and a reduction in bone turnover. Within the category of anti-resorptives: estrogen, selective estrogen receptor modulators, tibolone, calcitonin, bisphosphonates and denosumab all reduce vertebral fractures risk, but differ in their ability to reduce the risk of non-vertebral fractures in randomized clinical trials. This chapter will discuss the data on these effects for each class of anti-resorptive agent.

Hip and non-spine fracture risk reductions differ among antiresorptive agents: Evidence from randomised controlled trials

A number of antiresorptive agents reduce the risk of vertebral fractures, but few have shown consistent effects on hip and other non-spine fractures. Meta-analysis provides a more precise estimate than individual trials when results are consistent across pooled trials. Earlier meta-analyses summarised the results for vertebral and non-spine fractures. New data have emerged for hormone therapy (HT), alendronate (ALN), risedronate (RIS) and ibandronate (IBN). We surveyed recent reports of randomised, placebo-controlled trials with non-spine and/or hip fracture data, and used meta-analysis where appropriate to test for heterogeneity and derive pooled estimates. The magnitude of effect on hip fracture appears to be similar to that for non-spine fracture for each drug, but differs among drugs. Based on the current data, ALN reduces the risk of hip and non-spine fracture by 49-55%, HT by 25-36% and RIS by 26-27%. There is insufficient and/or inconsistent evidence of an effect on these fractures for IBN, calcitonin and raloxifene.

The role of amylin and related peptides in osteoporosis

Osteoporosis is a systemic skeletal disorder that remains a major public health problem due to significant fracture-associated morbidity and mortality. Because it has been shown that individuals having type I diabetes mellitus also suffer from osteopenia or osteoporosis, there is probably a pathophysiological mechanism that links pancreatic beta cell insufficiency with inappropriate bone formation. Many factors have been suggested, including amylin, a product of pancreatic beta cells with structural and functional similarity to calcitonin. Amylin has been shown to stimulate bone development via action on osteoblasts and osteoclasts. Recently, amylin receptors have been identified as complexed calcitonin receptor with receptor activity modifying proteins. Moreover, a synthetic amylin analogue (pramlintide) has been developed for clinical use. These findings including results from in vitro animal and human studies suggest a role for amylin as a potential diagnostic and therapeutical tool in patients with various bone diseases including osteoporosis. However, other structurally and functionally related hormones that affect bone metabolism should also be taken in account including calcitonin, calcitonin gene-related peptide and adrenomedullin.