Association of hyperhomocysteinemia with osteoporosis: a systematic review

An investigation into the impact and implications of published papers from retracted research: systematic search of affected literature

OBJECTIVE

Analyses of the impact of a body of clinical trial reports subject to research misconduct have been few. Our objective was to examine the impact on clinically relevant research of a group of researchers' trial reports ('affected trial reports') affected by research misconduct, and whether identification of misconduct invoked a reappraisal.

DESIGN

In 2016, we used five databases and search engines to identify 'citing publications', that is, guidelines, systematic and other reviews, and clinical trials citing any of 12 affected trial reports, published 1998-2011, eventually retracted for research misconduct. The affected trial reports were assessed more likely to have had impact because they had hip fracture outcomes and were in journals with impact factor >4. Two authors assessed whether findings of the citing publications would change if the affected trial reports were removed. In 2018, we searched for evidence that the citing publications had undertaken a reassessment as a result of the potential influence of the affected trial reports.

RESULTS

By 2016 the affected trial reports were cited in 1158 publications, including 68 systematic reviews, meta-analyses, narrative reviews, guidelines and clinical trials. We judged that 13 guidelines, systematic or other reviews would likely change their findings if the affected trial reports were removed, and in another eight it was unclear if findings would change. By 2018, only one of the 68 citing publications, a systematic review, appeared to have undertaken a reassessment, which led to a correction.

CONCLUSIONS

We found evidence that this group of affected trial reports distorted the evidence base. Correction of these distortions is slow, uncoordinated and inconsistent. Unless there is a rapid, systematic, coordinated approach by bibliographic databases, authors, journals and publishers to mitigate the impact of known cases of research misconduct, patients, other researchers and their funders may continue to be adversely affected.

New horizons in treatment of osteoporosis

BACKGROUND

Prevalence of osteoporosis is increasing both in developed and developing countries. Due to rapid growth in the burden and cost of osteoporosis, worldwide, it seems reasonable to focus on the reduction of fractures as the main goal of treatment. Although, efficient pharmacological agents are available for the treatment of osteoporosis, there still remains a need to more specific drugs with less adverse effects.

MAIN BODY

This review article provides a brief update on the pathogenesis, presenting current pharmacological products approved by the US Food and Drug Administration (FDA) or Europe, and also newer therapeutic agents to treat osteoporosis according to the clinical trial data available at PubMed, UpToDate, International Osteoporosis Foundation (IOF), and clinical practice guidelines. As well, the effect of combination therapy and recommendations for future research will be further discussed.

SHORT CONCLUSION

The use of current antiresorptive and anabolic agents alone or in combinations for the treatment of osteoporosis entails several limitations. Mainly, their efficacy on non-vertebral fracture reduction is lower than that observed on vertebral fracture. In addition, they have potential adverse events on long time usage. Development of newer agents such as cathepsin k inhibitor and strontium ranelate not only have increased the available options for treating osteoporosis, but also have opened doors of opportunity to improvements in the effective treatment. However, the high cost of new agents have restricted their usage in selective patients who are at high risk of fracture or whom failed response to first line treatment options. Thus, personalized medicine should be considered for future evaluation of genetic risk score and also for environmental exposure assessment. In addition to permanent attention to early diagnosis of osteoporosis and understanding of the pathophysiology of osteoporosis for novel approach in drug discovery, there seems a need to more well-designed clinical trials with larger sample sizes and longer duration on current as well as on newer agents. Also, continuous research on plant-derived components as the source of discovering new agents, and conducting more clinical trials with combination of two or more synthetic drugs, plants, or drug-plant for the treatment of osteoporosis are recommended. Summary of treatment modalities for osteoporosis.

Effect of folic acid on bone metabolism: a randomized double blind clinical trial in postmenopausal osteoporotic women

BACKGROUND

In spite of several studies, the impact of homocysteine level and folic acid supplementation on bone metabolism is yet to be recognized. In this registered clinical trial (IRCT2014042217385N1), we aimed to find out the power of 6-month folic acid supplementation on homocysteine level and bone metabolism.

METHODS

Forty postmenopausal osteoporotic women (50 to 87 years) were enrolled in the study. All participants were randomized to receive folic acid 1 mg (n = 17) or placebo (n = 14). At baseline, 3 months, and finally 6 months post intervention, the level of homocysteine, vitamin B12, and bone biomarkers were measured.

RESULTS

Both groups were similar at baseline. The homocysteine decreased in both groups but statistically non-significant (P > 0.05). The changes of the serum level of vitamin B12, osteocalcin, and β cross laps were significant between groups after 6 months (P ≤ 0.05).

CONCLUSION

The trend of changes of bone biomarkers after 6 months folic acid supplementation shows that homocysteine concentration and/or folic acid supplementation have impact on the rate of bone metabolism. However, further investigations by larger sample size and differentiating age and gender are still needed to clarify the exact role of folate, homocysteine and vitamin B12.

Prevention of bone resorption by intake of phytoestrogens in postmenopausal women: a meta-analysis

Phytoestrogens as selective estrogen receptor modulators like compounds may consider as a therapeutic option in osteoporosis. In this regard, the effect of phytoestrogens on bone biomarkers was examined in several trials which their results are controversial. We aimed this meta-analysis to evaluate the net effect of phytoestrogens on bone markers. A thorough search was conducted from 2000 to 2010 in English articles. All randomized clinical trials were reviewed, and finally, 11 eligible randomized clinical trials were selected for meta-analysis. Totally 1,252 postmenopausal women were enrolled in the study by considering the changes of pyridinoline (Pyd), desoxypyridinoline (Dpyd), bone alkaline phosphatase, and osteocalcin concentrations in urine and serum after phytoestrogens consumption. The urine Pyd and Dpyd levels decreased significantly in phytoestrogens consumers. Effect size and effect size for weighted mean difference of urine Pyd levels showed -1.229171 (95% confidence interval (CI) = -1.927639 to -0.530703) and -9.780623 (95% CI = -14.240401 to -5.320845), respectively, a significant results in comparison to control group and significant results for Dpyd -0.520132 (95% CI = -0.871988 to -0.168275) and -0.818582 (95% CI = -1.247758 to -0.389407), respectively. Meta-analysis indicates that phytoestrogens intake can prevent bone resorption, but its benefits on bone formation are not significant. This favorable effect was observed in low doses and in at least 3 weeks of phytoestrogens intake.

Current, new and future treatments of osteoporosis

Osteoporosis as a common chronic disease is challenging human health. Although different therapeutic options are routinely used for prevention/treatment of osteoporosis, their side effects and benefits are under question. Increasing our knowledge about signaling pathways in bone and osteocytes as well as osteoblasts and osteoclasts will help us in designing new therapeutic modalities for osteoporosis. In the present study, all new therapeutic measures of osteoporosis have been reviewed. For this purpose, search engines like Pubmed, Web of Science, Scopus, Google Scholar were searched and all relevant articles were found. The study was limited to the year 1998-2010. Bisphosphonates are the cornerstone of osteoporosis treatment, but there are not enough relevant studies that investigated their equivalencies in comparison with each other or the other medications. Therefore, medication selection is empirical and subjective. Furthermore, no eminent study has compared certain combinations. There are new hopes for treatment of osteoporosis, which are more specific with less harm. Our results show that new and emerging therapies are more potent and target specified which more individualize osteoporosis treatment; however, more investigations on their safety and efficacy in comparison with current medications are highly recommended.

The effect of n-3 fatty acids on bone biomarkers in Iranian postmenopausal osteoporotic women: a randomized clinical trial

Recently, n-3 fatty acids are in the center of attention for their potent anti-inflammatory effects. Osteoporosis as a chronic senile disease is associated with inflammation, and the role of inflammatory mediators has been demonstrated in recent years. The beneficial effects of n-3 fatty acids on bone were proven in many animal studies, while to date, no conclusive data is available in human. The aim of this study was to evaluate the impact of n-3 fatty acids on bone biomarkers in osteoporotic postmenopausal women. Twenty-five osteoporotic postmenopausal women were recruited in the study and randomized in treatment and control groups. The patients received 900 mg n-3 fatty acid capsules or placebo per day for 6 months. Serum levels of osteocalcin, bone alkaline phosphatase (BALP), calcium, vitamin D, and parathormone and urine concentration of pyridinoline (Pyd) were measured at baseline, second month, and sixth month in both groups. In the treatment group, compared with baseline, at the second month, osteocalcin increased slightly; thereafter, it showed decrement trend until the end of the study. In the control group, it decreased all over the study. None of these changes was significant. BALP showed nonsignificant decrease from baseline over the time in both groups. Urine level of Pyd decreased significantly (P < 0.05) in the treatment group, while no significant change was seen in the control group. Serum calcium and vitamin D increased in both groups; however, changes were not significant. No significant changes were seen in calcium clearance and parathormone. In conclusion, n-3 fatty acids can decrease bone resorption; however, it could not affect bone formation significantly after 6 months treatment. Further investigations are recommended.