Medical treatment of osteoporotic vertebral fractures

Increased PHOSPHO1 and alkaline phosphatase expression during the anabolic bone response to intermittent parathyroid hormone delivery

The administration of intermittent parathyroid hormone (iPTH) is anabolic to the skeleton. Recent studies with cultured osteoblasts have revealed that the expression of PHOSPHO1, a bone-specific phosphatase essential for the initiation of mineralisation, is regulated by PTH. Therefore, this study sought to determine whether the bone anabolic response to iPTH involves modulation of expression of Phospho1 and of other enzymes critical for bone matrix mineralisation. To mimic iPTH treatment, primary murine osteoblasts were challenged with 50 nM PTH for 6 h in every 48 h period for 8 days (4 cycles), 14 days (7 cycles) and 20 days (10 cycles) in total. The expression of both Phospho1 and Smpd3 was almost completely inhibited after 4 cycles, whereas 10 cycles were required to stimulate a similar response in Alpl expression. To explore the in vivo role of PHOSPHO1 in PTH-mediated osteogenesis, the effects of 14- and 28-day iPTH (80 µg/kg/day) administration was assessed in male wild-type (WT) and Phospho1-/- mice. The expression of Phospho1, Alpl, Smpd3, Enpp1, Runx2 and Trps1 expression was enhanced in the femora of WT mice following iPTH administration but remained unchanged in the femora of Phospho1-/- mice. After 28 days of iPTH administration, the anabolic response in the femora of WT was greater than that noted in Phospho1-/- mice. Specifically, cortical and trabecular bone volume/total volume, as well as cortical thickness, were increased in femora of iPTH-treated WT but not in iPTH-treated Phospho1-/- mice. Trabecular bone osteoblast number was also increased in iPTH-treated WT mice but not in iPTH-treated Phospho1-/-  mice. The increased levels of Phospho1, Alpl, Enpp1 and Smpd3 in WT mice in response to iPTH administration is consistent with their contribution to the potent anabolic properties of iPTH in bone. Furthermore, as the anabolic response to iPTH was attenuated in mice deficient in PHOSPHO1, this suggests that the osteoanabolic effects of iPTH are at least partly mediated via bone mineralisation processes.

Bioactivity, Molecular Mechanism, and Targeted Delivery of Flavonoids for Bone Loss

Skeletal disabilities are a prominent burden on the present population with an increasing life span. Advances in osteopathy have provided various medical support for bone-related diseases, including pharmacological and prosthesis interventions. However, therapeutics and post-surgery complications are often reported due to side effects associated with modern-day therapies. Thus, therapies utilizing natural means with fewer toxic or other side effects are the key to acceptable interventions. Flavonoids constitute a class of bioactive compounds found in dietary supplements, and their pharmacological attributes have been well appreciated. Recently, flavonoids' role is gaining renowned interest for its effect on bone remodeling. A wide range of flavonoids has been found to play a pivotal role in the major bone signaling pathways, such as wingless-related integration site (Wnt)/β-catenin, bone morphogenetic protein (BMP)/transforming growth factor (TGF)-β, mitogen-activated protein kinase (MAPK), etc. However, the reduced bioavailability and the absorption of flavonoids are the major limitations inhibiting their use against bone-related complications. Recent utilization of nanotechnological approaches and other delivery methods (biomaterial scaffolds, micelles) to target and control release can enhance the absorption and bioavailability of flavonoids. Thus, we have tried to recapitulate the understanding of the role of flavonoids in regulating signaling mechanisms affecting bone remodeling and various delivery methods utilized to enhance their therapeutical potential in treating bone loss.

Cellular Senescence in Bone

Senescence is an irreversible cell-cycle arrest process induced by environmental, genetic, and epigenetic factors. An accumulation of senescent cells in bone results in age-related disorders, and one of the common problems is osteoporosis. Deciphering the basic mechanisms contributing to the chronic ailments of aging may uncover new avenues for targeted treatment. This review focuses on the mechanisms and the most relevant research advancements in skeletal cellular senescence. To identify new options for the treatment or prevention of age-related chronic diseases, researchers have targeted hallmarks of aging, including telomere attrition, genomic instability, cellular senescence, and epigenetic alterations. First, this chapter provides an overview of the fundamentals of bone tissue, the causes of skeletal involution, and the role of cellular senescence in bone and bone diseases such as osteoporosis. Next, this review will discuss the utilization of pharmacological interventions in aging tissues and, more specifically, highlight the role of senescent cells to identify the most effective and safe strategies.

Identification of osteoporosis based on gene biomarkers using support vector machine

Osteoporosis is a major health concern worldwide. The present study aimed to identify effective biomarkers for osteoporosis detection. In osteoporosis, 559 differentially expressed genes (DEGs) were enriched in PI3K-Akt signaling pathway and Foxo signaling pathway. Weighted gene co-expression network analysis showed that green, pink, and tan modules were clinically significant modules, and that six genes (VEGFA, DDX5, SOD2, HNRNPD, EIF5B, and HSP90B1) were identified as “real” hub genes in the protein–protein interaction network, co-expression network, and 559 DEGs. The sensitivity and specificity of the support vector machine (SVM) for identifying patients with osteoporosis was 100%, with an area under curve of 1 in both training and validation datasets. Our results indicated that the current system using the SVM method could identify patients with osteoporosis.

Dietary Collagen Hydrolysates Retard Estrogen Deficiency-Induced Bone Loss through Blocking Osteoclastic Activation and Enhancing Osteoblastic Matrix Mineralization

Osteoporosis manifest in postmenopausal women is an osteolytic disease characterized by bone loss, leading to increased susceptibility to bone fractures and frailty. The use of complementary therapies to alleviate postmenopausal osteoporosis is fairly widespread among women. The current study examined that Pangasius hypophthalmus fish skin collagen hydrolysates (fsCH) inhibited ovariectomy (OVX)-induced bone loss by conducting inter-comparative experiments for anti-osteoporotic activity among 206–618 mg/kg fsCH, 2 mg/kg isoflavone, 15 mg/kg glycine–proline–hydroxyproline (GPH) tripeptide, and calcium lactate. Surgical estrogen loss of mice for 8 weeks reduced serum 17β-estradiol levels with uterus atrophy, which was ameliorated by orally administering fsCH or isoflavone to mice. Similar to isoflavone, fsCH containing GPH-enhanced bone mineral density reduced levels of cathepsin K and proton-handling proteins, and elevated collagen 1 level in OVX bones. The treatment with fsCH and isoflavone enhanced the serum levels of collagen synthesis-related procollagen type 1 carboxy/amino-terminal propeptides reduced by OVX, whereas serum levels of osteocalcin and alkaline phosphatase, as well as collagen breakdown-related carboxy/amino-terminal telopeptides of type 1 collagen were reduced in OVX mice treated with fsCH, isoflavone, and calcium lactate. The trabecular bones were newly formed in OVX bones treated with isoflavone and fsCH, but not with calcium lactate. However, a low-dose combination of fsCH and calcium lactate had a beneficial synergy effect on postmenopausal osteoporosis. Furthermore, similar to isoflavone, 15–70 μg/mL fsCH, with its constituents of GPH and dipeptides of glycine–proline and proline–hydroxyproline, enhanced osteogenesis through stimulating differentiation, matrix mineralization, and calcium deposition of MC3T3-E1 osteoblasts. Accordingly, the presence of fsCH may encumber estrogen deficiency-induced bone loss through enhancing osteoclastogenic differentiation and matrix collagen synthesis. Therefore, fsCH may be a natural compound retarding postmenopausal osteoporosis and pathological osteoresorptive disorders.

Osteoprotective effects of flavonoids: Evidence from in vivo and in vitro studies (Review)

Osteoporosis is a systemic bone disease characterized by decreased bone mass and quality and bone micro‑architecture degradation. Its primary cause is disorder of bone metabolism: Over‑formation of osteoclasts, resulting in increased bone resorption and insufficient osteogenesis. Traditional herbal flavonoids can be used as alternative drugs to prevent and treat osteoporosis due to their wide range of sources, structural diversity and less adverse effects. The present paper reviewed six flavonoids, including quercetin, icariin, hesperitin, naringin, chrysin and pueraria, that promote bone formation and have been widely studied in the literature over the past five years, with the aim of providing novel ideas for the development of drugs for bone‑associated disease.

Osteoporosis therapies and their mechanisms of action (Review)

Osteoporosis is a common disease that affects millions of patients worldwide and is most common in menopausal women. The main characteristics of osteoporosis are low bone density and increased risk of fractures due to deterioration of the bone architecture. Osteoporosis is a chronic disease that is difficult to treat; thus, investigations into novel effective therapeutic methods are required. A number of studies have focused on determining the most effective treatment options for this disease. There are several treatment options for osteoporosis that differ depending on the characteristics of the disease, and these include both well-established and newly developed drugs. The present review focuses on the various drugs available for osteoporosis, the associated mechanisms of action and the methods of administration.

Overview of treatment approaches to osteoporosis

Efficient therapies are available for the treatment of osteoporosis. Anti-resorptive therapies, including bisphosphonates and denosumab, increase bone mineral density (BMD) and reduce the risk of fractures by 20-70%. Bone-forming or dual-action treatments stimulate bone formation and increase BMD more than the anti-resorptive therapies. Two studies have demonstrated that these treatments are superior to anti-resorptives in preventing fractures in patients with severe osteoporosis. Bone-forming or dual-action treatments should be followed by anti-resorptive treatment to maintain the fracture risk reduction. The BMD gains seen with bone-forming and dual-action treatments are greater in treatment-naïve patients compared to patients pretreated with anti-resorptive treatments. However, the antifracture efficacy seems to be preserved. Treatment failure will often lead to switch of treatment from orally to parentally administrated anti-resorptives treatment or from anti-resorptive to bone-forming or dual-action treatment. Osteoporosis is a chronic condition and therefore needs a long-term management plan with a personalized approach to treatment. LINKED ARTICLES: This article is part of a themed issue on The molecular pharmacology of bone and cancer-related bone diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.9/issuetoc.

Effect of medications on prevention of secondary osteoporotic vertebral compression fracture, non-vertebral fracture, and discontinuation due to adverse events: a meta-analysis of randomized controlled trials

BACKGROUND

Bone loss with aging and menopause increases the risk of fragile vertebral fracture, osteoporotic vertebral compression fracture (OVCF). The fracture causes severe pain, impedes respiratory function, lower the quality of life, and increases the risk of new fractures and deaths. Various medications have been prescribed to prevent a secondary fracture, but few study summarized their effects. Therefore, we investigated their effects on preventing subsequent OVCF via meta-analyses of randomized controlled trials.

METHODS

Electronic databases, including MEDLINE, EMBASE, CENTRAL, and Web of Science were searched for published randomized controlled trials from June 2015 to June 2019. The trials that recruited participants with at least one OVCF were included. We assessed the risk of bias of every study, estimated relative risk ratio of secondary OVCF, non-vertebral fracture, gastrointestinal complaints and discontinuation due to adverse events. Finally, we evaluated the quality of evidence.

RESULTS

Forty-one articles were included. Moderate to high quality evidence proved the effectiveness of zoledronate (Relative Risk, RR: 0.34; 95% CI, 0.17-0.69, p = 0.003), alendronate (RR: 0.54; 95% CI: 0.43-0.68; p < 0.0001), risedronate (RR: 0.61; 95% CI: 0.51-0.73; p < 0.0001), etidronate (RR, 0.50; 95% CI, 0.29-0.87, p < 0.01), ibandronate (RR: 0.52; 95% CI: 0.38-0.71; p < 0.0001), parathyroid hormone (RR: 0.31; 95% CI: 0.23-0.41; p < 0.0001), denosumab (RR, 0.41; 95% CI, 0.29-0.57; p < 0.0001) and selective estrogen receptor modulators (Raloxifene, RR: 0.58; 95% CI: 0.44-0.76; p < 0.0001; Bazedoxifene, RR: 0.66; 95% CI: 0.53-0.82; p = 0.0002) in preventing secondary fractures. Moderate quality evidence proved romosozumab had better effect than alendronate (Romosozumab vs. alendronate, RR: 0.64; 95% CI: 0.49-0.84; p = 0.001) and high quality evidence proved that teriparatide had better effect than risedronate (risedronate vs. teriparatide, RR: 1.98; 95% CI: 1.44-2.70; p < 0.0001).

CONCLUSION

Zoledronate, alendronate, risedronate, etidronate, ibandronate, parathyroid hormone, denosumab and selective estrogen receptor modulators had significant secondary prevention effects on OVCF. Moderate quality evidence proved romosozumab had better effect than alendronate. High quality evidence proved PTH had better effect than risedronate, but with higher risk of adverse events.

Treatment of Osteoporosis: Unmet Needs and Emerging Solutions

Efficient therapies are available for the treatment of osteoporosis, however, there are still unmet needs. Anti-resorptive therapies only increase bone mineral density to a certain extent and reduce the risk of non-vertebral fractures by 20%, only one anabolic option is available in most parts of the world-the effect of which levels off over time, and the evidence for combination therapy targeting both resorption and formation is limited. In addition, identification and treatment of patients with high and imminent fracture risk following a recent fracture and long-term adherence to treatment are 2 other very prominent challenges to the management of osteoporosis. The current review will focus on emerging osteoporosis treatments and optimized use of the existing treatments that may help overcome the currently unmet needs in the management of osteoporosis.

New horizons in osteoporosis therapies

Efficient therapies are available for the treatment of osteoporosis, however, there are still unmet needs. Anti-resorptive therapies only increase bone mineral density to a certain extent and reduce the risk of non-vertebral fractures by 20%, only one anabolic option is available-the effect of which levels off over time, and the evidence for combination therapy targeting both resorption and formation is limited. The current review will focus on emerging treatments of osteoporosis with the potential of enhanced anabolic effects (romosozumab and abaloparatide) or uncoupling of resorption and formation (odanacatib and romosozumab) as well as the effect of combination therapy.

Resistance training programs on bone related variables and functional independence of postmenopausal women in pharmacological treatment: A randomized controlled trial

INTRODUCTION

Osteoporosis is a chronic disease that leads to bone fragility and is associated with fracture risks and serious consequences for mobility.

OBJECTIVE

To verify the effects of two linear programs of resistance training (RT) on bone mineral density (BMD), functional autonomy (FA), muscular strength and quality of life (QoL) of postmenopausal women in pharmacological treatment.

STUDY DESIGN

Randomized controlled trial, code: RBR-6bqsw8.

METHODS

52 volunteers were distributed into three groups, according to randomly parallel form: RT3times-per-week (RT3, n=20); RT2times-per-week (RT2, n=16) and control group (CG, n=16). The following assessment tools were used: bone mineral density (BMD) by dual X-ray absorptiometry, 'Latin America Group for maturity' (GDLAM) protocol for FA, 10RM test for leg exercises and the 'Osteoporosis Assessment Questionnaire' (OPAQ) for QoL. The physical activities were planned for 13 months in cycles with different intensities. A two-way ANOVA with Bonferroni post-hoc test were used.

RESULTS

The results showed that the RT3/week was significantly more efficient (p<0.05) compared with RT2/week, including: All BMD variables, FA (Δ%=29.3%), leg press at 45° (Δ%=24.97%) and OPAQ (Δ%=20.23%). In addition, both RT3 and RT2 groups were more efficient (p<0.05) compared with CG, including: total BMD (Δ%=0.09%) and (Δ%=0.06%); FA (Δ%=7.1%) and RT2 (Δ%=3.78%); Leg press at 45° (Δ%=84.1%) and (Δ%=59.1%); keen extension (Δ%=15.28%) and (Δ%=20.37%); OPAQ (Δ%=57.61%) and (Δ%=37.37%), respectively.

CONCLUSION

The study showed that both experimental groups presented favorable results for BMD, strength, FA and QoL. However, the RT3 showed the best results compared to other groups after 13 months of intervention.

National healthcare budget impact analysis of the treatment for osteoporosis and fractures in Korea

Background

This study was to determine the impact on the national healthcare expenditure for the treatment of osteoporosis and fractures if the coverage period for osteoporosis medication was extended from maximum a year to continuous period as required.

Methods

Preserving the current reimbursement guidelines, maximum one year's coverage for osteoporosis medication was set as scenario A. Continuous coverage for patients who require medication was set as scenario B. As costs of medical service utilization are paid by the Korean National Health Insurance Program, all items were investigated and analyzed from the payer's perspective. The combined treatment costs for osteoporosis and osteoporotic fractures were assessed for each scenario.

Results

Over five years the cost of osteoporosis medication in scenario A will increase from 184.3 billion KRW to 204.6 billion KRW. The cost of osteoporotic fracture treatment will increase from 1,037.3 billion KRW to 1,822.7 billion KRW. In scenario B, the cost of osteoporosis medication will increase from 209.5 billion KRW to 388.1 KRW. The cost of osteoporotic fracture treatment will increase from 600.0 billion KRW to 1,054.3 billion KRW. The result showed savings of 2.50 trillion KRW cumulatively for five years when reimbursement coverage for osteoporosis treatments is extended from one year to as long as it's clinically required.

Conclusions

This study demonstrates that effective osteoporosis management through appropriate insurance coverage for osteoporosis medication should be considered not only for the patient's viewpoint, but in terms of national insurance budget as well.

Functional autonomy, bone mineral density (BMD) and serum osteocalcin levels in older female participants of an aquatic exercise program (AAG)

The aim of the present study was to evaluate the effects of an AAG on BMD, osteocalcin and functional autonomy in older women. The sample consisted of eighty-two post-menopausal women with low BMD, randomly divided into two groups: the Aquatic Aerobics Group [AAG; n=42; age: 66.8±4.2years], submitted to two weekly sessions over eight months, and the Control Group (GC; n=42; age: 66.9±3.2years), which did not participate in regular exercise. BMD was measured by Dual Energy X-ray Absorptiometry [DXA] of the lumbar and femur, and serum osteocalcin was measured using electrochemiluminescence. A functional autonomy assessment protocol (GDLAM, 2004) was also applied. Statistical analyses used were repeated measures ANOVA and Tukey's post hoc tests. The results showed a significant improvement in tests following the GDLAM protocol: 10 meters walk (10mw) -p=0.003; rising from a ventral decubitus position (RVDP) - Δ%=0.78, p<0.001; rising from a chair and moving around the house (RCMH) -p<0.001 and autonomy index (AI) -p=0.007, with more favorable results observed in the AAG when compared to the CG. The AAG achieved the best results for BMD; however, no inter or intragroup statistical differences were recorded for total femur -p=0.975 and lumbar L(2)-L(4)p=0.597. For serum osteocalcin, intra and intergroup statistical differences of p=0.042 and p=0.027 were observed in the AAG, respectively. This demonstrates that an eight-month aquatic aerobic exercise program can improve functional autonomy and osteocalcin levels, although training did not improve lumbar and total femur BMD in the older women.

Aging and bone loss: new insights for the clinician

It is well known that the underlying mechanisms of osteoporosis in older adults are different than those associated with estrogen deprivation. Age-related bone loss involves a gradual and progressive decline, which is also seen in men. Markedly increased bone resorption leads to the initial fall in bone mineral density. With increasing age, there is also a significant reduction in bone formation. This is mostly due to a shift from osteoblastogenesis to predominant adipogenesis in the bone marrow, which also has a lipotoxic effect that affects matrix formation and mineralization. We review new evidence on the pathophysiology of age-related bone loss with emphasis upon the mechanism of action of current osteoporosis treatments. New potential treatments are also considered, including therapeutic approaches to osteoporosis in the elderly that focus on the pathophysiology and potential reversal of adipogenic shift in bone.