Comparative effects of antiresorptive agents on bone mineral density and bone turnover in postmenopausal women

Real-world effectiveness of osteoporosis treatments in Germany

This observational study assessed the impact on the fracture incidence of osteoporosis medications in postmenopausal women in Germany. Continued treatment with osteoporosis medications was associated with reductions of fracture rates in a real-world setting.

PURPOSE

The efficacy of osteoporosis medications has been demonstrated in clinical trials, but a lack of evidence exists of their real-world effectiveness. This real-world study assessed the treatment patterns and impact on the fracture incidence of osteoporosis medications in postmenopausal women in Germany.

METHODS

This cohort study used data from the WIG2 benchmark database, a German anonymised healthcare claims database. All women ≥ 50 years of age with ≥ 1 prescription for osteoporosis medication between 1 January 2013 and 31 December 2017 were included. The primary outcome was treatment effectiveness, evaluated as the change in fracture incidence after initiating treatment. Fracture types included all fractures, clinical vertebral, hip and wrist/forearm. Fracture incidence was assessed during the early-treatment period (0-3 months) and the on-treatment period (4-12, 13-24, 25-36 and 37-48 months).

RESULTS

Baseline covariates and treatment patterns were determined for 41,861 patients. The median duration of therapy was longer with denosumab (587 days) than with intravenous ibandronate (451 days), intravenous zoledronate (389 days) or oral bisphosphonates (258 days). The baseline incidence rate of all fractures was higher in patients receiving denosumab than in those receiving other treatments (87.6, 78.2, 56.6 and 66.0 per 1000 person-years for denosumab, oral bisphosphonates, intravenous ibandronate and intravenous zoledronate, respectively). Rates of all fractures declined with continued denosumab (by 38%, 50%, 56% and 67% at 12, 24, 36 and 48 months, respectively) and oral bisphosphonates (by 39%, 44%, 49% and 42%, respectively) treatment.

CONCLUSION

Continued treatment with osteoporosis medications was associated with reductions of fracture rates in a real-world setting.

Comparison of Bone Mineral Density and Markers of Bone Turnover in Osteoporotic Women after 6-Month Treatment with Alendronate or Bazedoxifene: A Randomized Controlled Trial

Background

In a randomized controlled trial, we compared the bone mineral densities (BMDs) and blood markers of bone turnover during short-term treatment of osteoporotic women with bisphosphonate alendronate or bazedoxifene, a selective estrogen receptor modulator.

Methods

Ten and eleven patients were randomized to the alendronate and bazedoxifene groups, respectively. BMDs were measured before and after 6 months of treatment. Blood tests were used to measure the levels of osteocalcin (OC), C-terminal telopeptide of type I collagen (CTX), vitamin D3, and parathyroid hormone pretreatment and after 3 and 6 months of treatment. The variables were compared statistically.

Results

The alendronate group showed decreases in blood levels of both OC and CTX during the study period (P<0.001 and P=0.002, respectively), while the bazedoxifene group had a decrease only in OC levels (P=0.012). After 6 months of treatment, BMDs significantly increased in the alendronate group at multiple bone sites, including the L1–4 lumbar vertebrae, femur trochanter, and total femur. However, there was no significant increase in BMD in the bazedoxifene group. BMDs were not significantly different between the 2 groups.

Conclusions

Patients treated with alendronate showed more rapid suppression of markers of bone turnover and higher BMD than those treated with bazedoxifene during a short-term regime. Considering the effects and complications of each medication, the relationship between bone turnover rate and bone quality will need to be investigated in future studies.

A Novel Peptide, CK2.3, Improved Bone Formation in Ovariectomized Sprague Dawley Rats

Osteoporosis is a bone disease that has no definite cure. Current treatments for osteoporosis are divided into two categories: anti-resorptive and anabolic. However, these treatments are not perfect and have considerable risks. In addition, bone quality often declines over time with these treatments. We designed a peptide, CK2.3, that has both anabolic and anti-resorptive effects on bone. We reported that CK2.3 induced osteoblastic mineralization, promoted bone formation, and suppressed osteoclastogenesis in vivo. The effect of CK2.3 to rescue an osteoporosis phenotype model has never been shown. In this study, we demonstrated the effect of CK2.3 in ovariectomized rats, a standard model of osteoporosis. We systemically injected CK2.3 at 2.3 µg/kg each day for five consecutive days. Micro-computed tomography indicated that CK2.3 increased bone mineral density, (bone volume/tissue volume) BV/TV and (trabecular number) TbN, and decreased (trabecular space) TbSp in the femoral head. Similarly, single photon absorptiometry showed that treatment with CK2.3 increased bone mineral density in the lumbar spine and the pelvis. Additionally, we observed increased femoral shaft stiffness with ovariectomized rats treated with CK2.3. We also detected no significant changes in the weight of organs such as the heart, lung, liver, kidney, and spleen. An advantage of CK2.3 over current treatments was that it not only promoted bone formation but also improved fracture resistance. In conclusion, we demonstrated CK2.3 as a new anabolic treatment for osteoporosis.

A novel anti-osteoporotic agent that protects against postmenopausal bone loss by regulating bone formation and bone resorption

AIMS

Postmenopausal osteoporosis is a bone metabolism disease that is caused by an imbalance between bone-resorbing osteoclast and bone-forming osteoblast actions. Herein, we describe the role of troxerutin (TRX), a trihydroxyethylated derivative of rutin, in ovariectomy (OVX)-induced osteoporosis and its effects on the regulation of osteoclasts and osteoblasts.

MAIN METHODS

In vivo, OVX female mice were intraperitoneally injected with either saline, 50 mg/kg TRX, or 150 mg/kg TRX for 6 weeks and then sacrificed for micro-computed tomography analyses, histological analyses, and biomechanical testing. In vitro, RAW264.7 cell-derived osteoclasts and MC3T3-E1 cell-derived osteoblasts were treated with different concentrations of TRX to examine the effect of TRX on osteoclastogenesis and bone resorption, as well as on osteogenesis and mineralization.

KEY FINDINGS

In this study, we demonstrated that TRX prevented cortical and trabecular bone loss in ovariectomized mice by reducing osteoclastogenesis and promoting osteogenesis in vivo. In vitro, TRX inhibited the formation and activity of RAW264.7-derived osteoclasts and the expression of nuclear factor of activated T-cells 1 and cathepsin K. Meanwhile, TRX improved the osteogenesis and mineralization of MC3T3-E1 by enhancing the expression of Runt-related transcription factor 2, Osterix, and collagen type 1 alpha 1.

SIGNIFICANCE

Our data demonstrated that TRX could prevent OVX-induced osteoporosis and be used in a novel treatment for postmenopausal osteoporosis.

A Review on Bone Mineral Density Loss in Total Knee Replacements Leading to Increased Fracture Risk

The link between low bone mineral density (BMD) scores leading to greater fracture risk is well established in the literature; what is not fully understood is the impact of total knee replacements/revisions or arthroplasties on BMD levels. This literature review attempts to answer this question. Several different databases using specific key terms were searched, with additional papers retrieved via bibliographic review. Based on the available evidence, total knee replacements/revisions and arthroplasties lower BMD and thus increase fracture risk. This review also addresses the possible implications of this research and possible options to reduce this risk.

A polymorphism at the translation start site of the vitamin D receptor gene is associated with the response to anti-osteoporotic therapy in postmenopausal women from southern Italy

The present study investigated the effect of two single nucleotide polymorphisms (SNPs) of the vitamin D receptor (VDR) gene, rs1544410 A/G and rs2228570 C/T, in modulating bone mineral density (BMD) and the response to treatment with bisphosphonates or strontium ranelate in postmenopausal osteoporosis (PMO). Four hundred eighteen postmenopausal women from Southern Italy treated with bisphosphonates or strontium ranelate for three years were enrolled and stratified according to their genotype. Changes in BMD were expressed as the delta t-score (Δt-score). Allelic frequencies for rs1544410 A/GSNP were 11.2% AA, 50.0% GA and 38.8% GG; for rs2228570 C/TSNP were 54.8% CC, 39.5% TC and 5.7% TT. TT carriers showed a lower t-score than TC and CC (both p < 0.02) genotypes and were more responsive to the therapy when compared to both TC (p < 0.02) and CC (p < 0.05) carriers. Specifically, TT carriers receiving alendronate demonstrated a significant improvement of the Δt-score compared to TC and CC (both p < 0.0001) carriers. After adjustment for confounders, the Δt-score showed evidence of a statistically significant positive association with TT in all treatments considered. Therapy response was independent of rs1544410 A/G SNP; instead, rs2228570 C/TSNP was associated with a better response to antiresorptive treatment, thus suggesting that the therapy for PMO should be personalized.

The clinical utility of bone marker measurements in osteoporosis

Osteoporosis is characterised by low bone mass and structural deterioration of bone tissue, resulting in increased fragility and susceptibility to fracture. Osteoporotic fractures are a significant cause of morbidity and mortality. Direct medical costs from such fractures in the UK are currently estimated at over two billion pounds per year, resulting in a substantial healthcare burden that is expected to rise exponentially due to increasing life expectancy. Currently bone mineral density is the WHO standard for diagnosis of osteoporosis, but poor sensitivity means that potential fractures will be missed if it is used alone. During the past decade considerable progress has been made in the identification and characterisation of specific biomarkers to aid the management of metabolic bone disease. Technological developments have greatly enhanced assay performance producing reliable, rapid, non-invasive cost effective assays with improved sensitivity and specificity. We now have a greater understanding of the need to regulate pre-analytical sample collection to minimise the effects of biological variation. However, bone turnover markers (BTMs) still have limited clinical utility. It is not routinely recommended to use BTMs to select those at risk of fractures, but baseline measurements of resorption markers are useful before commencement of anti-resorptive treatment and can be checked 3–6 months later to monitor response and adherence to treatment. Similarly, formation markers can be used to monitor bone forming agents. BTMs may also be useful when monitoring patients during treatment holidays and aid in the decision as to when therapy should be recommenced. Recent recommendations by the Bone Marker Standards Working Group propose to standardise research and include a specific marker of bone resorption (CTX) and bone formation (P1NP) in all future studies. It is hoped that improved research in turn will lead to optimised markers for the clinical management of osteoporosis and other bone diseases.

Effects of genistein aglycone in osteoporotic, ovariectomized rats: a comparison with alendronate, raloxifene and oestradiol

Background and purpose:

Genistein aglycone positively affects bone loss in postmenopausal women, but bone quality data are still lacking. To clarify this, we investigated the effects of genistein compared with alendronate, raloxifene and oestradiol in an animal model of established osteoporosis.

Experimental approach:

Six months after ovariectomy, 96 ovariectomized (OVX) rats were divided into 8 equal groups, randomized to treatments (genistein aglycone (1 and 10 mg kg⁻¹ s.c.); alendronate (0.003 and 0.03 mg kg⁻¹ s.c.); raloxifene hydrochloride (0.05 and 0.5 mg kg⁻¹ s.c.); 17-α-ethinyl oestradiol (0.003 and 0.03 mg kg⁻¹ s.c.)) for 12 weeks. Untreated OVX (n=12) and sham OVX (n=12) were used as controls. At the beginning and end of treatment, bone mineral density (BMD) and bone mineral content (BMC) were assessed. At the end of the experiment, calcium, phosphorus, bone-alkaline phosphatase (b-ALP), collagen C-telopeptide (CTX), osteoprotegerin (OPG) and soluble receptor activator of nuclear factor-κB ligand (sRANKL) were assayed. Femurs were removed and tested for breaking strength and histology.

Key results:

Genistein (10 mg kg⁻¹) showed a greater increase in both BMD (P<0.0001 vs OVX) and BMC than all the other treatments. Moreover, genistein significantly increased breaking strength, bone quality, b-ALP (P<0.0001 vs OVX) and OPG, and reduced CTX and sRANKL compared with the other treatments at all dose levels.

Conclusions and implications:

The results strongly suggest that the genistein aglycone might be a new therapy for the management of postmenopausal osteoporosis in humans.