Randomized Teriparatide [human parathyroid hormone (PTH) 1-34] Once-Weekly Efficacy Research (TOWER) trial for examining the reduction in new vertebral fractures in subjects with primary osteoporosis and high fracture risk

PTH1 receptor agonists for fracture risk: a systematic review and network meta-analysis

Osteoporosis, defined by reduced bone mineral density and macro- and micro-architectural degradation, leads to increased fracture risk, particularly in aging populations. While randomized controlled trials (RCTs) demonstrate that PTH1 receptor agonists, teriparatide and abaloparatide, are effective at reducing fracture risk, real-world evidence (RWE) remains sparse. This study reviews and compares the anti-fracture efficacy of these agents, against each other and against other osteoporosis treatments using both RCTs and RWE. We systematically searched Medline, Embase, and Cochrane up to May 2024, focusing on RCTs and RWE studies reporting reduction in vertebral, non-vertebral, hip, or all fractures as primary endpoint. A network meta-analysis (NMA) was conducted, first through pairwise meta-analyses of teriparatide versus abaloparatide, then a Bayesian NMA comparing each to other treatments. Safety assessments included adverse events classified by MedDRA, with a particular attention to hypercalcemia and cardiac events. Seventeen studies (11 RCTs, 6 RWE) met inclusion criteria. Teriparatide and abaloparatide were effective in reducing vertebral and non-vertebral fractures in all pairwise meta-analyses versus placebo. Abaloparatide showed an advantage over teriparatide for non-vertebral fractures (OR: 0.87, 95% CI: 0.80-0.95) and hip fractures (OR: 0.81, 95% CI: 0.71-0.93). In the NMA model, teriparatide and abaloparatide were superior to placebo, raloxifene, and calcitonin in reducing vertebral fracture while teriparatide was further superior to denosumab and risedronate. For non-vertebral fracture, abaloparatide was better than any other treatment while teriparatide was only superior to alendronate or placebo. PTH1 analogs were better than placebo at reducing all fractures while no difference was observed for the risk of hip fracture. Both abaloparatide and teriparatide demonstrate comparable safety to other osteoporosis treatments, with no increased cardiovascular risk. This review highlights that PTH1 receptor agonists effectively reduce fracture risk, with abaloparatide offering enhanced benefits for non-vertebral and hip fractures compared to teriparatide. Both agents exhibit acceptable safety profiles, suggesting their valuable role in managing osteoporosis, particularly for high-risk patients.

Combined vitamin K2 and D3 therapy improves endoscopic fusion outcomes in osteoporotic lumbar degenerative disease: a prospective study

The efficacy of combined vitamin K2 and D3 therapy on bone fusion outcomes following endoscopic lumbar surgery in osteoporotic patients remains unclear. This prospective study investigated the effects of combined vitamin K2 and D3 supplementation on fusion outcomes in osteoporotic patients undergoing endoscopic lumbar interbody fusion. Seventy-one patients were divided into two groups: the experimental group (n = 36) received vitamin K2 (45 mg/day), vitamin D3 (250 IU/day), and calcium (1.2 g/day), while the control group (n = 35) received only vitamin D3 (250 IU/day) and calcium (1.2 g/day) for 6 months postoperatively. The primary outcome was fusion rate assessed by CT and dynamic radiography. At 6 months postoperatively, the VK2 + VD3 group showed significantly higher complete fusion rates compared to the control group (91.67% vs. 74.29%, P = 0.044). Serum P1NP levels were significantly higher in the VK2 + VD3 group at 3 months postoperatively (P = 0.001). Both groups showed comparable improvements in clinical outcomes (JOA-BPEQ and ODI scores). While BMD changes were not statistically significant between groups, the VK2 + VD3 group showed a trend toward BMD improvement. These findings suggest that combined vitamin K2 and D3 supplementation may enhance early fusion outcomes in osteoporotic patients undergoing endoscopic lumbar interbody fusion, potentially offering a simple and effective adjunct therapy for improving surgical outcomes.

Teriparatide as a non-surgical salvage therapy for prolonged humerus fracture nonunion: A case report and literature review

BACKGROUND

Fracture nonunion represents a challenging complication during fracture repair, often necessitating surgical intervention. Teriparatide, a recombinant human parathyroid hormone, has demonstrated promise in enhancing fracture healing, although its efficacy in treating established nonunion remains under investigation.

CASE SUMMARY

We report a case of a 27-year-old male who presented with a right humerus fracture following a traffic accident. Despite undergoing open reduction and internal fixation, the fracture resulted in a delayed union and subsequent nonunion. After 4 years of conservative management, teriparatide treatment was initiated due to persistent nonunion. Teriparatide injections were administered daily for 6 months, resulting in complete fracture healing and resolution of pain.

CONCLUSION

Our case demonstrates the successful use of teriparatide in treating a prolonged nonunion of a humerus fracture. Teriparatide may provide a valuable therapeutic option for established bone nonunion, even in cases that have not responded to conservative treatments.

Clinical effects of teriparatide, abaloparatide, and romosozumab in postmenopausal osteoporosis

In the management of osteoporosis, anti-resorptive agents serve as a primary therapeutic approach. However, in cases where individuals exhibit an increased susceptibility to fractures, such as those characterized by severe low bone mass or a history of vertebral or hip fractures that markedly diminish life expectancy, the immediate reduction of fracture risk through the administration of osteoanabolic agents could be beneficial. Teriparatide, available in daily, once-weekly, or twice-weekly dosages, along with abaloparatide and romosozumab, constitutes a trio of such agents. Each of these medications is defined by unique characteristics, distinct efficacy profiles, and specific adverse effects. There is growing evidence to suggest that these agents have a superior effect on enhancing bone mineral density and reducing fracture incidence when compared to traditional bisphosphonate therapies. Nonetheless, their employment demands thorough consideration of clinical indications, which includes evaluating economic factors, the frequency of injections required, and the potential for adverse effects. The objective of this review is to consolidate the current evidence focusing primarily on the efficacy of these agents, with the goal of enhancing understanding and aiding in making more informed treatment decisions, particularly for those individuals who are at an elevated risk of fractures.

Sequential therapy following teriparatide treatment in patients at high risk of osteoporotic patients

The use of medications in sequence is recommended in several osteoporosis guidelines to afford the best protection for the patient at very high risk of fracture. Sequential therapy following once-weekly as well as daily teriparatide treatment is a potent option for those patients.

Association between renal function and fracture incidence during treatment with teriparatide or alendronate: an exploratory subgroup analysis of the Japanese Osteoporosis Intervention Trial-05

The association of renal function with fracture incidence during teriparatide or alendronate treatment in elderly Japanese women was examined. Fracture incidence differed by fracture type, renal function, and treatment protocol. The results provide important information on pharmacotherapy in clinical practice for osteoporosis.

PURPOSE

Incidence rate of morphometric vertebral fracture was lower under treatment with once-weekly teriparatide (TPTD) followed by alendronate (ALN) than under treatment with ALN throughout the study among elderly Japanese women at high fracture risk in JOINT-05. This is an exploratory subgroup analysis according to chronic kidney disease (CKD) status at baseline.

METHODS

Participants received sequential therapy with TPTD for 72 weeks, followed by ALN for 48 weeks (TPTD-ALN group, N = 483) or ALN monotherapy for 120 weeks (ALN group, N = 496). Baseline CKD status was classified by the estimated glomerular filtration rate (eGFR) and categorized as: CKD 1/2 (eGFR ≥ 60 mL/min/1.73 m2), CKD 3a (eGFR 45-59 mL/min/1.73 m2), or CKD 3b/4 (eGFR < 45 mL/min/1.73 m2). Incidences of vertebral fractures including morphometric fractures, non-vertebral fractures, and all fractures were evaluated during follow-up.

RESULTS

Baseline characteristics were not different between treatment groups. Higher stages of CKD were associated with age and number of prevalent vertebral fracture. In CKD 1/2 patients (N = 556 with 90 incidents of morphometric vertebral fracture), the incidence of vertebral fractures was lower in the TPTD-ALN group than in the ALN group (p = 0.01). In CKD 3b/4 patients (N = 112 with 10 incidents of non-vertebral fracture), the incidence of non-vertebral fractures was lower in the ALN group than in the TPTD-ALN group, although the number of fractures was small. In the ALN group, the incidences of vertebral fractures, non-vertebral fractures, and all fractures remained constant across CKD stages.

CONCLUSION

This exploratory analysis showed that fracture incidence on ALN was constant regardless of renal function. It also suggested that the incidence of vertebral fractures on TPTD-ALN was lower than ALN monotherapy in CKD 1/2 patients. These results provide important information for drug selection in the clinical practice of osteoporosis.

Effects of daily teriparatide, weekly high-dose teriparatide, or bisphosphonate on cortical and trabecular bone of vertebra and proximal femur in postmenopausal women with fragility fracture: Sub-analysis by quantitative computed tomography from the TERABIT study

PURPOSE

The effects of daily teriparatide (D-PTH, 20 μg/day), weekly high-dose teriparatide (W-PTH, 56.5 μg/week), or bisphosphonate (BP) on the vertebra and proximal femur were investigated using quantitative computed tomography (QCT).

METHODS

A total of 131 postmenopausal women with a history of fragility fractures were randomized to receive D-PTH, W-PTH, or bisphosphonate (oral alendronate or risedronate). QCT were evaluated at baseline and after 18 months of treatment.

RESULTS

A total of 86 participants were evaluated by QCT (Spine: D-PTH: 25, W-PTH: 21, BP: 29. Hip: PTH: 22, W-PTH: 21, BP: 32. Dropout rate: 30.5 %). QCT of the vertebra showed that D-PTH, W-PTH, and BP increased total vBMD (+34.8 %, +18.2 %, +11.1 %), trabecular vBMD (+50.8 %, +20.8 %, +12.2 %), and marginal vBMD (+20.0 %, +14.0 %, +11.5 %). The increase in trabecular vBMD was greater in the D-PTH group than in the W-PTH and BP groups. QCT of the proximal femur showed that D-PTH, W-PTH, and BP increased total vBMD (+2.8 %, +3.6 %, +3.2 %) and trabecular vBMD (+7.7 %, +5.1 %, +3.4 %), while only W-PTH and BP significantly increased cortical vBMD (-0.1 %, +1.5 %, +1.6 %). Although there was no significant increase in cortical vBMD in the D-PTH group, cortical bone volume (BV) increased in all three treatment groups (+2.1 %, +3.6 %, +3.1 %).

CONCLUSIONS

D-PTH had a strong effect on trabecular bone of vertebra. Although D-PTH did not increase cortical BMD of proximal femur, it increased cortical BV. W-PTH had a moderate effect on trabecular bone of vertebra, while it increased both cortical BMD and BV of proximal femur. Although BP had a limited effect on trabecular bone of vertebra compared to teriparatide, it increased both cortical BMD and BV of proximal femur.

Discovery of Novel Antiosteoporosis Leads with Bone Resorption Inhibition and Anabolic Promotion through a Chemotype-Assembly Approach

Developing a dual-efficiency agent with antiresorptive and anabolic applications is a promising strategy for treating osteoporosis. This study reports the discovery of dual antiosteoporosis agents via a chemotype-assembly approach. Chemotype analysis identified 12 antiresorptive and 12 anabolic chemotypes and 7 dual-function chemotype-assembly rules. Based on these assembly rules, a dual-functional compound S24 was discovered. S24 exhibits osteoclastogenesis inhibition with an IC50 value of 10.28 μM and osteoblast differentiation stimulation at 10 μM. S24 derivatives were designed and synthesized based on the activity relationship of the chemotypes. This yielded a more active compound, S24-14, with an osteoclastogenesis inhibition IC50 value of 0.40 μM and osteoblast differentiation stimulation at 1.0 μM; compound S24-14 also suppressed bone loss in vivo. These results prove that S24-14 can be a potential lead for antiosteoporosis drug development.

A crossover comparison of patient satisfaction with two teriparatide regimens: primary results of the Japanese Osteoporosis Intervention Trial 06 (JOINT-06)

INTRODUCTION

This study aimed to compare treatment satisfaction with two dosing regimens (two teriparatide [TPTD] self-injection systems) in osteoporosis patients at high risk of fracture.

MATERIALS AND METHODS

In this open-label crossover randomized trial comparing self-injected once-daily (1/D)-TPTD with self-injected twice-weekly (2/W)-TPTD, three satisfaction variables were evaluated by questionnaire for 2 years. The primary endpoint was overall satisfaction and secondary endpoints were satisfaction with treatment effectiveness and with utility of the self-injection device. Changes in quality of life (QOL) assessed by EuroQol-5 Dimension, pain assessed by visual analogue scale (VAS), and anthropometric parameters were also analyzed. Safety was evaluated based on the incidence and severity of adverse events (AEs).

RESULTS

The 1/D-TPTD and 2/W-TPTD groups consisted of 180 (75.9 ± 7.3 years) and 179 (age: 75.5 ± 6.9 years) patients, respectively. After 26 weeks of treatment, no significant between-group difference in the persistence rate (79.4% vs 72.6% in the 1/D-TPTD and 2/W-TPTD groups, respectively), distributions of overall satisfaction scores, and satisfaction with treatment (p > 0.05) were observed. However, several items of satisfaction with the utility of the injection device were significantly higher in the 2/W-TPTD group (p < 0.05). Statistical improvements from baseline values were observed in QOL and pain VAS in both groups (p < 0.05). No serious AEs were reported.

CONCLUSION

The between-group similarity of overall treatment satisfaction and effectiveness scores and between-group difference in satisfaction with the utility of the self-injection device was useful information for real-world treatment of osteoporosis. Both medication regimens were well tolerated.

Independent Risk Factors of Proximal Junctional Kyphosis with Vertebral Fracture After Spinal Long Fusion: Survivorship Analysis of Adult Spinal Deformity Surgery Patients

OBJECTIVE

This study aimed to identify risk factors for postoperative proximal junctional kyphosis (PJK) with vertebral fracture in adult spinal deformity (ASD) patients. We performed a survival analysis considering various factors, including osteoporosis.

METHODS

This single-center retrospective study included 101 ASD patients (mean age: 67.2 years, mean follow-up: 8.1 years). We included patients aged ≥50 years with abnormal radiographic variables undergoing corrective long spinal fusion. The main outcome measure was PJK with vertebral fracture, analyzed based on patient data, radiographic measurements, sagittal parameters, bone mineral density, and osteoporosis medication.

RESULTS

PJK occurred in 37.6% of patients, with vertebral fracture type 2 accounting for 65% of these cases. Kaplan-Meier analysis indicated a median PJK-free survival time of 60.7 months. Existing vertebral fracture (grade 1 or higher or grade 2 or higher) was a significant risk factor for PJK with vertebral fracture, with hazard ratios of 4.58 and 5.61, respectively. The onset time of PJK with vertebral fracture was 1.5 months postoperatively, with 44% of these cases occurring within 1 month and 64% within 2 months.

CONCLUSIONS

PJK with vertebral fracture affected 25% of ASD patients, emphasizing the importance of osteoporosis evaluation. Existing vertebral fracture emerged as a significant independent risk factor, surpassing bone mineral density. This study provides valuable insights for spine surgeons, highlighting the need to provide osteoporosis treatment and emphasize potential postoperative complications during discussions with patients.

Oral daily PTH(1-34) tablets (EB613) in postmenopausal women with low BMD or osteoporosis: a randomized, placebo-controlled, 6-month, phase 2 study

Anabolic treatment is indicated for high and very-high risk patients with osteoporosis, but acceptance is limited because current anabolic medications require subcutaneous injections. The purpose of this study was to assess the effects of a novel orally administered PTH tablet on serum markers of bone formation (PINP and osteocalcin), bone resorption (crosslinked C-telopeptide [CTX]), BMD, and safety in postmenopausal women with low BMD or osteoporosis. In this 6-mo, double-blind, placebo-controlled study, 161 patients were randomized to oral PTH tablets containing 0.5, 1.0, 1.5, or 2.5 mg or placebo daily. Biochemical markers were assessed at 1, 2, 3, and 6 mo and BMD of LS, TH, and FN was measured at 6 mo. Biochemical marker changes were dose dependent with minimal or no effect at the 2 lowest doses. At the highest dose (2.5 mg once daily), serum PINP and OC levels increased 30% within 1 mo after oral PTH initiation (P < .0001), remained elevated through 3 mo, and were back to baseline at 6 mo. In contrast, serum CTX levels declined 16% and 21% below baseline at 3 and 6 mo, respectively (both P ≤ .02). At 6 mo, 2.5 mg tablets increased mean BMD vs placebo of the LS by 2.7%, TH by 1.8%, and FN by 2.8% (all P ≤ .01). There were no drug-related serious adverse events. The most common adverse events were headache, nausea, and dizziness. In contrast to subcutaneous PTH, the oral PTH tablet appears to increase BMD rapidly by the dual mechanism of stimulating formation and inhibiting bone resorption. This might be the first effective oral anabolic alternative to subcutaneous administration for the treatment of low BMD or osteoporosis.

Effects of differences in dose and frequency of teriparatide on bone structure in Proximal Femur. - Analysis by DXA-based 3D-modeling (3D-SHAPER Software) -TRIPLE-BONE study (The effects of TeRIParatide preparation on bone mineraL density increase and BONE structure)

Trends toward more favorable improvement of the cortical bone parameters by once-weekly (56.5 μg once a week) and twice-weekly teriparatide (28.2 μg twice a week), and that of the trabecular bone parameters by once-daily (1/D) teriparatide (20 μg/day once a day) were shown.

PURPOSE

To examine the effects of differences in the amount of teriparatide (TPTD) per administration and its dosing frequency on the bone structure in the proximal femur by dual-energy X-ray absorptiometry (DXA)-based 3D-modeling (3D-SHAPER software).

METHODS

This was a multicenter retrospective study. Patients aged 50 years or older with primary osteoporosis who continuously received once-/twice-weekly (1・2/W, n = 60) or 1/D TPTD (n = 14) administration for at least one year were included in the study. Measurement regions included the femoral neck (FN), trochanter (TR), femoral shaft (FS), and total proximal hip (TH). Concurrently, the bone mineral density (BMD) and Trabecular Bone Score (TBS) were measured.

RESULTS

The cross-sectional area, cross-sectional moment of inertia, and section modulus in the FS were significantly improved in the 1・2/W TPTD group, as compared to the 1/D TPTD group. However, significant improvement of the cortical thickness and buckling ratio in the FN was observed in the 1/D TPTD group, as compared to the 1・2/W TPTD group. Trabecular BMD values in the FS and TH were significantly increased in the 1/D TPTD group, as compared to the 1・2/W TPTD group, while the cortical BMD values in the TR, FS, and TH were significantly increased in the 1・2/W TPTD group, as compared to the 1/D TPTD group.

CONCLUSION

Trends toward more favorable improvement of the cortical bone by 1・2/W TPTD and that of the trabecular bones by 1/D TPTD were observed.

Effects of daily versus weekly teriparatide for medication-related osteonecrosis of the jaw: A case-control study

INTRODUCTION

Medication-related osteonecrosis of the jaw (MRONJ) is uncommon but can result in severe destruction of the jaw. This case-control study investigated the therapeutic effects of daily or weekly administration of teriparatide in the management of MRONJ using a cohort for osteonecrosis of the jaw.

METHODS

Patients who were diagnosed with MRONJ and consented to teriparatide administration were assigned either to a group of daily injection or of weekly injection and completed a 4-week course of injection preoperatively and at least an 8-week course postoperatively. The control group received either the intraoperative rhBMP treatment (CG_BMP) or no additional perioperative treatment (CG_noBMP). The state of MRONJ was evaluated 2 months (T1) and 6 months (T2) postoperatively for all participants.

RESULTS

Either group of daily injection (8.35 weeks ± 1.58; n = 17) or weekly injection (9.17 ± 3.79; n = 12) showed significantly faster healing than those of CG_BMP (14.40 ± 6.08; n = 25) or CG_noBMP (15.79 ± 9.79; n = 39). MRONJ was resolved completely in 24 out of 29 participants who completed the course of teriparatide injections, whereas 46.9% of CG showed delayed resolution. Multiple regression analysis indicated 7.50 times (95% CI, 1.77-31.82) more likelihood of complete resolution of MRONJ for participants with teriparatide injections.

CONCLUSION

A course of daily or weekly administration of teriparatide injections may improve treatment outcomes for patients with MRONJ.

Predictive role of FRAX© for postoperative proximal junctional kyphosis with vertebral fracture after adult spinal deformity surgery

PURPOSE

To identify risk factors, including FRAX (a tool for assessing osteoporosis) scores, for development of proximal junctional kyphosis (PJK), defined as Type 2 in the Yagi-Boachie classification (bone failure), with vertebral fracture (VF) after surgery for symptomatic adult spinal deformity.

METHODS

This was a retrospective, single institution study of 127 adults who had undergone corrective long spinal fusion of six or more spinal segments for spinal deformity and been followed up for at least 2 years. The main outcome was postoperative development of PJK with VF. Possible predictors of this outcome studied included age at surgery, BMI, selected radiographic measurements, bone mineral density, and 10-year probability of major osteoporotic fracture (MOF) as determined by FRAX. We also analyzed use of medications for osteoporosis. Associations between the selected variables and PJK with VF were assessed by the Mann-Whitney, Fishers exact, and Wilcoxon signed-rank tests, and Kaplan-Meier analysis, as indicated.

RESULTS

Forty patients (31.5%) developed PJK with VF postoperatively,73% of them within 6 months of surgery. Statistical analysis of the selected variables found that only a preoperative estimate by FRAX of a > 15% risk of MOF within 10 years, pelvic tilt > 30° at first standing postoperatively and lower instrumented level (fusion terminating at the pelvis) were significantly associated with development of PJK with VF.

CONCLUSION

Preoperative assessment of severity of osteoporosis using FRAX provides an accurate estimate of risk of postoperative PJK with VF after surgery for adult spinal deformity.

Two-Year Outcomes of Daily and Twice-Weekly Teriparatide Treatment in Postmenopausal Women with Severe Osteoporosis: A Randomized Non-Blinded Prospective Study

BACKGROUND

The long-term effects of daily teriparatide (D-TPTD) and twice-weekly TPTD (W-TPTD) injections are compared among postmenopausal women with severe osteoporosis.

METHODS

A total of 102 patients were enrolled and randomly allocated into two groups for the administration of either D-TPTD or W-TPTD. Treatment efficacy was measured as the percentage change in bone mineral density (ΔBMD) from baseline in the lumbar spine, total hip, and femoral neck. The findings were compared between the two groups.

RESULTS

At 24 months after treatment, the persistence rates and medication possession ratios in the D-TPTD and W-TPTD groups were 68.6% and 56.9%, and 87.8% and 92.0%, respectively. The ΔBMD in the lumbar spine, total hip, and femoral neck were 15.6%±10.2%, 5.3%± 6.3%, and 5.5%±6.2%, respectively, in the D-TPTD group; and 9.5%±7.9%, 2.3%±6.2%, and 3.1%±7.4%, respectively, in the W-TPTD group following 24 months of treatment. The ΔBMD of the lumbar spine (p=0.008) at 24 months and total hip (p=0.024) at 18 months differed significantly between the two groups.

CONCLUSIONS

D-TPTD administration resulted in a significantly higher BMD in the lumbar spine and total hip, supporting this therapeutic regimen for postmenopausal women with severe osteoporosis.

Optimal Intermittent Administration Interval of Abaloparatide for Bone Morphogenetic Protein-Induced Bone Formation in a Rat Spinal Fusion Model

Both bone morphogenetic protein 2 (BMP-2) and abaloparatide are used to promote bone formation. However, there is no consensus about their optimal administration. We investigated the optimal administration theory for the pairing of BMP-2 and abaloparatide in a rat spinal fusion model. Group I was only implanted in carriers and saline. Carriers with 3 µg of recombinant human BMP-2 (rhBMP-2) were implanted in other groups. Abaloparatide injections were administered three times a week for group III (for a total amount of 120 µg/kg in a week) and six times a week for group IV (for a total amount of 120 µg/kg in a week) after surgery. They were euthanized 8 weeks after the surgery, and we explanted their spines at that time. We assessed them using manual palpation tests, radiography, high-resolution micro-computed tomography (micro-CT), and histological analysis. We also analyzed serum bone metabolism markers. The fusion rate in Groups III and IV was higher than in Group I, referring to the manual palpation tests. Groups III and IV recorded greater radiographic scores than those in Groups I and II, too. Micro-CT analysis showed that Tbs. Sp in Groups III and IV was significantly lower than in Group I. Tb. N in Group IV was significantly higher than in Group I. Serum marker analysis showed that bone formation markers were higher in Groups III and IV than in Group I. On the other hand, bone resorption markers were lower in Group IV than in Group I. A histological analysis showed enhanced trabecular bone osteogenesis in Group IV. Frequent administration of abaloparatide may be suitable for the thickening of trabecular bone structure and the enhancement of osteogenesis in a rat spinal fusion model using BMP-2 in insufficient doses.

[Osteoporosis treatment for fracture prevention in elderly]

Fracture prevention in the elderly is an urgent issue at all levels: individual, family, and societal. Osteoporosis is the underlying cause of fractures in the elderly, and it is important to understand its pathogenesis and treatment. Diet, exercise, and pharmacotherapy are all important for fracture prevention. Particularly with regard to pharmacotherapy, it is important to understand the mechanism of action of each drug and its characteristics and problems from a clinical point of view. Appropriate treatment of osteoporosis has been proven to reduce fractures in the elderly, and its widespread implementation is desirable.

Follow-up Bone Mineral Density Testing: 2023 Official Positions of the International Society for Clinical Densitometry

Dual-energy X-ray absorptiometry (DXA) is the gold standard method for measuring bone mineral density (BMD) which is most strongly associated with fracture risk. BMD is therefore the basis for the World Health Organization's densitometric definition of osteoporosis. The International Society for Clinical Densitometry (ISCD) promotes best densitometry practices and its official positions reflect critical review of current evidence by domain experts. This document reports new official positions regarding follow-up DXA examinations based on a systematic review of literature published through December 2022. Adoption of official positions requires consensus agreement from an expert panel following a modified RAND protocol. Unless explicitly altered by the new position statements, prior ISCD official positions remain in force. This update reflects increased consideration of the clinical context prompting repeat examination. Follow-up DXA should be performed with pre-defined objectives when the results would have an impact on patient management. Testing intervals should be individualized according to the patient's age, sex, fracture risk and treatment history. Incident fractures and therapeutic approach are key considerations. Appropriately ordered and interpreted follow-up DXA examinations support diagnostic and therapeutic decision making, thereby contributing to excellent clinical care. Future research should address the complementary roles of clinical findings, imaging and laboratory testing to guide management.

Nocebo-associated treatment discontinuation with subcutaneous anti-osteoporotic drugs. A systematic review and meta-analysis of placebo-arm dropouts in randomized-controlled trials

OBJECTIVE

Nocebo is a concept of therapeutics referring to unpleasant symptoms attributed by a patient to a drug, due to negative anticipation. Patients receiving oral anti-osteoporotic drugs in randomized controlled trials (RCT) can experience adverse events leading to dropout, implying that nocebo contributes to treatment discontinuation for these drugs. In this study we aim to investigate the nocebo effect of subcutaneous anti-osteoporotic drugs with a higher compliance rate than orally administered drugs.

STUDY DESIGN

We searched MEDLINE, EMBASE, SCOPUS, and Cochrane databases for double-blind trials investigating subcutaneous anti-osteoporotic drugs for osteoporosis (namely, denosumab, teriparatide, abaloparatide and romosozumab) published up to May 2023.

MAIN OUTCOME MEASURE

Dropouts due to reported adverse events in the placebo arms ("nocebo dropouts").

RESULTS

Data from 17 trials were extracted. Among 10,529 placebo-treated patients the pooled nocebo-dropout percentage was 3 % for denosumab (average: 0.03; 95 % CI: 0.01-0.05), 1 % for romosozumab (average: 0.01; 95 % CI: 0.00-0.03) and 6 % for teriparatide and abaloparatide (average: 0.06; 95 % CI: 0.05-0.07). Nocebo-dropouts were significantly higher in men than women (6 % vs. 3 %, respectively, p = 0.012), in older (mean age >68 years) than in younger patients (5 % vs. 1 %, respectively, p = 0.017) and in those with more severe osteoporosis (based on the percentage of participants with prior fragility-related fractures in the study cohort) compared with patients with no prior fracture history (4 % vs. 1 %, respectively, p = 0.046).

CONCLUSION

Nocebo responses may contribute to treatment discontinuation with subcutaneous anti-osteoporotic drugs in clinical practice. Higher nocebo-related dropout rates in the higher-risk RCT population (older patients, males, those with prior fractures) show that nocebo mechanisms have the potential to hinder therapeutic efforts to specific populations who would benefit most. Prospero registration number CRD42020212843.

Teriparatide and etelcalcetide improve bone, fibrosis, and fat parameters in chronic kidney disease model rats

Objectives

Chronic kidney disease (CKD) complicated by secondary hyperparathyroidism (SHPT) is associated with an increased risk of fragility fractures. Etelcalcetide (EC) is a treatment for SHPT that reduces serum parathyroid hormone (PTH) levels. However, the effects of combined treatment with osteoporosis drugs such as teriparatide (TPTD) remain unclear. This study investigates the combined effects of EC and TPTD on bone in CKD model rats.

Methods

The CKD model was established in 8-week-old male Wistar rats by feeding them a 0.75% adenine diet for 4 weeks. At 20 weeks of age, the rats were divided into 4 groups (N = 9-10 in each group): CKD group (vehicle administration), TPTD group (30 μg/kg, 3 times/week), EC group (0.6 mg/kg, daily), and Comb group (TPTD and EC combined). EC was injected for 12 weeks starting at 20 weeks of age, and TPTD was injected for 8 weeks starting at 24 weeks of age. After treatment, the followings were evaluated: bone mineral density, bone strength, biochemical tests, bone and fat histomorphometry, and micro-computed tomography.

Results

In CKD model rats, the combination of EC and TPTD was more effective in increasing cortical bone thickness and bone strength and inhibiting porosity. In addition, the combined treatment decreased bone marrow adiposity and fibrosis, and it increased bone mass and improved bone microstructure in trabecular bone.

Conclusions

With the observed benefits such as improved bone mass, bone strength, structural properties, and bone marrow adiposity, combination therapy may be a potential way to improve bone fragility in CKD.

Efficacy of Three Teriparatide Preparations and Romosozumab, Osteogenesis Promoters, in the Treatment of Fresh Vertebral Fractures: A Retrospective Observational Study

BACKGROUND

In Japan, daily, twice weekly, and weekly formulations of teriparatide (TPD) and monthly formulations of romosozumab (ROMO) are available as osteogenesis promoters for the treatment of osteoporosis with a high risk for fracture.

OBJECTIVE

To compare the effects of three TPD preparations and ROMO on fracture healing and low back pain after a fresh vertebral fracture.

METHODS

This was a retrospective observational study. Patients presenting with fresh osteoporotic vertebral fractures were treated subcutaneously with TPD daily (DTPD), twice weekly (2/WTPD), weekly (WTPD), or with ROMO monthly. Bone union, vertebral height changes, and low back pain in the injured vertebra were compared after 6 months of treatment.

RESULTS

Bone union and pain improvement were more frequent among those who received daily and twice weekly administration of TPD compared with those who received WTPD and ROMO administration. A comparison for multiplicity between the groups using the Steel-Dwass test showed significant differences between the DTPD and ROMO groups (p = 0.0029) and WTPD and ROMO groups (p = 0.0490), suggesting superior bone fusion in the DTPD and WTPD groups. Similarly, significant differences were noted between the DTPD and ROMO groups (p = 0.0001), WTPD and ROMO groups (p = 0.0341), and 2/WTPD and ROMO groups (p = 0.0009), indicating a higher degree of pain improvement in the DTPD, WTPD, and 2/WTPD groups compared with that in the ROMO group.

CONCLUSIONS

Daily, weekly, and twice-weekly administration of TPD may be superior to ROMO for promoting fresh vertebral fracture healing.

The effects of abaloparatide on hip geometry and biomechanical properties in Japanese osteoporotic patients assessed using DXA-based hip structural analysis: results of the Japanese phase 3 ACTIVE-J trial

Daily subcutaneous injection of 80 μg abaloparatide increased bone mineral density in Japanese patients with osteoporosis at high fracture risk in the ACTIVE-J trial. Dual-energy X-ray absorptiometry-based hip structural analysis from ACTIVE-J data showed improved hip geometry and biomechanical properties with abaloparatide compared with placebo.

PURPOSE

Abaloparatide (ABL) increased bone mineral density (BMD) in Japanese patients with osteoporosis at high fracture risk in the ACTIVE-J trial. To evaluate the effect of ABL on hip geometry and biomechanical properties, hip structural analysis (HSA) was performed using ACTIVE-J trial data.

METHODS

Hip dual-energy X-ray absorptiometry scans from postmenopausal women and men (ABL, n = 128; placebo, n = 65) at baseline and up to week 78 were analyzed to extract bone geometric parameters at the narrow neck (NN), intertrochanteric region (IT), and proximal femoral shaft (FS). Computed tomography (CT)-based BMD and HSA indices were compared between baseline and week 78.

RESULTS

ABL treatment showed increased mean percent change from baseline to week 78 in cortical thickness at the NN (5.3%), IT (5.3%), and FS (2.9%); cross-sectional area at the NN (5.0%), IT (5.0%), and FS (2.6%); cross-sectional moment of inertia at the NN (7.6%), IT (5.1%), and FS (2.5%); section modulus at the NN (7.4%), IT (5.4%), and FS (2.4%); and decreased mean percent change in buckling ratio (BR) at the IT (- 5.0%). ABL treatment showed increased mean percent change in total volumetric BMD (vBMD; 2.7%) and trabecular vBMD (3.2%) at the total hip and decreased mean percent change in BR at femoral neck (- 4.1%) at week 78 vs baseline. All the changes noted here were significant vs placebo (P < 0.050 using t-test).

CONCLUSION

A 78-week treatment with ABL showed improvement in HSA parameters associated with hip geometry and biomechanical properties vs placebo.

TRIAL REGISTRATION

JAPIC CTI-173575.

Protective effect of teriparatide against vancomycin-induced cytotoxicity in osteoblasts

BACKGROUND

Intrawound vancomycin powder is effective in preventing surgical site infection after spine surgery. In a previous study, vancomycin-induced cytotoxicity in osteoblasts was investigated in vitro, and vitamin D3 was verified to be a candidate drug aiding recovery from vancomycin-induced cytotoxicity. The treatment practices involving osteogenesis-promoting drugs vary widely. Teriparatide, an anabolic agent, highly promotes bone formation by inducing osteoblast activation, increasing bone formation and mineral density, and preventing vertebral fractures. Hence, teriparatide may be administered in combination with vancomycin.

METHODS

MC3T3-E1 cells were cultured in minimum essential medium supplemented with 10% fetal bovine serum at 37 °C in a humidified incubator containing 5% CO2. The experimental concentrations of vancomycin (2500, 5000, and 7500 μg/mL) were determined based on previous reports and our preliminary experiments. Teriparatide (100 ng/mL) was administered concomitantly to prevent cytotoxicity in osteoblasts, using pulsed vancomycin for 24 h (measured at 1, 3, and 7 days). Cell numbers and morphological changes in cells treated with vancomycin or vancomycin plus 100 ng/mL teriparatide were measured. Osteoblast differentiation was assessed using alkaline phosphatase staining, alkaline phosphatase activity, and alizarin red S staining.

RESULTS

Teriparatide showed a recovery effect when vancomycin (7500 μg/mL) was administered only for 24 h. Microscopic examination revealed that teriparatide had a protective effect on osteoblasts exposed to 7500 μg/mL vancomycin. Addition of teriparatide led to the recovery of alkaline phosphatase staining and alizarin red staining.

CONCLUSION

Vancomycin-induced cytotoxicity in osteoblasts could be inhibited by administering teriparatide concomitantly with vancomycin.

Risk Factors of Nonfusion after Anterior Cervical Decompression and Fusion in the Early Postoperative Period: A Retrospective Study

OBJECTIVE

Although high fusion rates have been reported for anterior cervical decompression and fusion (ACDF) in the medium and long term, the risk of nonfusion in the early period after ACDF remains substantial. This study investigates early risk factors for cage nonfusion in patients undergoing single- or multi-level ACDF.

METHODS

This was a retrospective study. From August 2020 to December 2021, 107 patients with ACDF, including 197 segments, were enrolled, with a follow-up of 3 months. Among the 197 segments, 155 were diagnosed with nonfusion (Nonfusion group), and 42 were diagnosed with fusion (Fusion group) in the early period after ACDF. We assessed the significance of the patient-specific factors, radiographic indicators, serum factors, and clinical outcomes. The Wilcoxon rank sum test, t-tests, analysis of variance, and stepwise multivariate logistic regression were used for statistical analysis.

RESULTS

Univariate analysis showed that smoking, insufficient improvement in the C2-7 Cobb angle (p = 0.024) and the functional spinal unit Cobb angle (p = 0.022) between preoperative and postoperative stages and lower serum calcium (fusion: 2.34 ± 0.12 mmol/L; nonfusion: 2.28 ± 0.17 mmol/L, p = 0.003) β-carboxyterminal telopeptide end of type 1 collagen (β-CTX) (fusion: 0.51 [0.38, 0.71]; nonfusion: 0.43 [0.31, 0.57], p = 0.008), and N-terminal fragment of osteocalcin (N-MID-BGP) (fusion: 18.30 [12.15, 22.60]; nonfusion: 14.45 [11.65, 18.60], p = 0.023) are risk factors for nonfusion in the early period after ACDF. Stepwise logistic regression analysis revealed that poor C2-7 Cobb angle improvement (odds ratio [OR], 1.107 [1.019-1.204], p = 0.017) and lower serum calcium (OR, 3.700 [1.138-12.032], p = 0.030) are risk factors.

CONCLUSIONS

Patients with successful fusion after ACDF had higher preoperative serum calcium and improved C2-7 Cobb angle than nonfusion patients at 3 months. These findings suggest that serum calcium could be used to identify patients at risk of nonfusion following ACDF and that correcting the C2-7 Cobb angle during surgery could potentially increase fusion in the early period after ACDF.

A Novel Long Noncoding RNA in Osteocytes Regulates Bone Formation through the Wnt/β-Catenin Signaling Pathway

The vast majority of transcribed RNAs are noncoding RNAs. Among noncoding RNAs, long noncoding RNAs (lncRNAs), which contain hundreds to thousands of bases, have received attention in many fields. The vast majority of the constituent cells in bone tissue are osteocytes, but their regulatory mechanisms are incompletely understood. Considering the wide range of potential contributions of lncRNAs to physiological processes and pathological conditions, we hypothesized that lncRNAs in osteocytes, which have not been reported, could be involved in bone metabolism. Here, we first isolated osteocytes from femurs of mice with osteocyte-specific GFP expression. Then, through RNA-sequencing, we identified osteocyte-specific lncRNAs and focused on a novel lncRNA, 9530026P05Rik (lncRNA953Rik), which strongly suppressed osteogenic differentiation. In the IDG-SW3 osteocyte line with lncRNA953Rik overexpression, the expression of Osterix and its downstream genes was reduced. RNA pull-down and subsequent LC-MS/MS analysis revealed that lncRNA953Rik bound the nuclear protein CCAR2. We demonstrated that CCAR2 promoted Wnt/β-catenin signaling and that lncRNA953Rik inhibited this pathway. lncRNA953Rik sequestered CCAR2 from HDAC1, leading to deacetylation of H3K27 in the Osterix promoter and consequent transcriptional downregulation of Osterix. This research is the first to clarify the role of a lncRNA in osteocytes. Our findings can pave the way for novel therapeutic options targeting lncRNAs in osteocytes to treat bone metabolic diseases such as osteoporosis.

Decrease in osteoporotic fracture in the western Kitakyushu region by the STOP-Fx study

INTRODUCTION

The Seamless Treatment of Osteoporosis against Fractures (STOP-Fx) study was initiated to provide and continue therapeutic interventions for registered patients with osteoporotic fractures.

MATERIALS AND METHODS

Women who visited six hospitals in the western Kitakyushu area for osteoporotic fractures between October 2016 and December 2018 were included in the study. Data collection for primary and secondary outcomes was conducted from October 2018 to December 2020, 2 years after STOP-Fx study enrollment. The primary outcome included the number of surgeries for osteoporotic fractures after the STOP-Fx study intervention, while secondary outcomes were the intervention rate of osteoporosis treatment, incidence and timing of secondary fractures, and factors associated with secondary fractures and loss to follow-up.

RESULTS

Concerning the primary outcome, the number of surgeries for osteoporotic fractures decreased since the STOP-Fx study initiation: 813 in 2017, 786 in 2018, 754 in 2019, 716 in 2020, and 683 in 2021. Regarding the secondary outcome, of the 805 patients enrolled, 445 were available for follow-up at 24 months. Of the 279 patients who were untreated for osteoporosis at enrollment, 255 (91%) were on treatment at 24 months. There were 28 secondary fractures, which were associated with increased tartrate-resistant acid phosphatase-5b and decreased lumbar spine bone mineral density during enrollment in the STOP-Fx study.

CONCLUSION

As the demographics and medical area served by six hospitals in the western Kitakyushu region have not changed significantly since the STOP-Fx study initiation, the STOP-Fx study may have contributed in decreasing the number of osteoporotic fractures.

Real-World Management of Patients With Osteoporosis at Very High Risk of Fracture

INTRODUCTION

Lack of consideration for risk-based assessments that inform osteoporosis treatment decisions may contribute to disease burden. In this study, we examined the prevalence of patients at very high risk of fracture and evaluated real-world treatment practices for these patients.

METHODS

This retrospective observational cohort study used real-world data linked to commercial and Medicare medical claims from Symphony Health PatientSource. Patients 50 years and older with osteoporosis (determined by the presence of a diagnosis code) and at very high risk of fracture according to the American Association of Clinical Endocrinologists (AACE) and American College of Endocrinology (ACE) (AACE/ACE) 2020 guidelines between January 1, 2018, and December 31, 2018, were included. The number and proportion of patients treated with any osteoporosis medication were evaluated.

RESULTS

Of the 10,739,286 patients with osteoporosis, 5,078,111 (47.3%) were identified as meeting the AACE criteria for very high risk of fracture and were selected for the analysis. Most (5,033,106 [99.1%]) had a high risk of falls and/or a history of falls resulting in injury. Among the 1,667,794 patients (32.8%) eligible for treatment, 280,777 (16.8%) received treatment. Of these, 63.6% received alendronate, an alternative therapy, and 21.2% received a risk-based guideline-recommended medicine (teriparatide, zoledronic acid, denosumab, abaloparatide, or romosozumab). A greater proportion of men were untreated, 161,978 (90.5) compared with 1,185,003 women (81.8).

DISCUSSION

Most patients at very high risk of fracture remain untreated. Most of those treated do not receive the appropriate recommended treatments for patients at high risk. Risk-based treatment decisions may allow for more appropriate medication selection.

Oral biosciences: The annual review 2022

BACKGROUND

The Journal of Oral Biosciences is devoted to advancing and disseminating fundamental knowledge concerning every aspect of oral biosciences.

HIGHLIGHT

This review features review articles in the fields of "Bone Cell Biology," "Tooth Development & Regeneration," "Tooth Bleaching," "Adipokines," "Milk Thistle," "Epithelial-Mesenchymal Transition," "Periodontitis," "Diagnosis," "Salivary Glands," "Tooth Root," "Exosome," "New Perspectives of Tooth Identification," "Dental Pulp," and "Saliva" in addition to the review articles by the winner of the "Lion Dental Research Award" ("Plastic changes in nociceptive pathways contributing to persistent orofacial pain") presented by the Japanese Association for Oral Biology.

CONCLUSION

The review articles in the Journal of Oral Biosciences have inspired its readers to broaden their knowledge about various aspects of oral biosciences. The current editorial review introduces these exciting review articles.

Comparison of different parameters between daily and twice-weekly teriparatide in postmenopausal women with severe osteoporosis

INTRODUCTION

Once-daily teriparatide (D-TPTD) and twice-weekly TPTD (W-TPTD), which are self-administered injections, are generally used in the treatment of severe osteoporosis. This study aimed to reveal the differences in the persistence, safety, and effectiveness of D-TPTD and W-TPTD.

MATERIALS AND METHODS

A total of 102 patients received D-TPTD (n = 51) and W-TPTD (n = 51). The bone mineral densities (BMD) of the lumbar spine, total hip, and femoral neck were measured using dual energy X-ray absorptiometry. The persistence and effectiveness of the two treatments were compared at 12 months.

RESULTS

The persistence in the D-TPTD and W-TPTD groups was 80.4% and 66.7% at 12 months, respectively (p = 0.178). The % changes (Δ) in BMD values from baseline for the lumbar spine in the D-TPTD were significantly higher than those in the W-TPTD (11.2% vs. 6.3%; p < 0.001) at 12 months. The ΔBMD values for the total hip (3.7% vs. 1.3%; p = 0.065) and femoral neck (2.2% vs. 1.6%; p = 0.489) did not differ significantly between the two groups at 12 months. The incidence of new morphological vertebral fractures in the D-TPTD and W-TPTD groups was 7.3% and 8.6%, respectively, at 12 months (p = 1.000).

CONCLUSIONS

Lumbar spine BMD (LS-BMD) was significantly increased. Moreover, ΔLS-BMD in the D-TPTD group was higher than that in the W-TPTD group. This study showed that the persistence, ΔTH-BMD, ΔFN-BMD and incidence of vertebral fractures did not differ between the two groups.

Pharmacologic Treatment of Primary Osteoporosis or Low Bone Mass to Prevent Fractures in Adults: A Living Clinical Guideline From the American College of Physicians

DESCRIPTION

This guideline updates the 2017 American College of Physicians (ACP) recommendations on pharmacologic treatment of primary osteoporosis or low bone mass to prevent fractures in adults.

METHODS

The ACP Clinical Guidelines Committee based these recommendations on an updated systematic review of evidence and graded them using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system.

AUDIENCE AND PATIENT POPULATION

The audience for this guideline includes all clinicians. The patient population includes adults with primary osteoporosis or low bone mass.

RECOMMENDATION 1A

ACP recommends that clinicians use bisphosphonates for initial pharmacologic treatment to reduce the risk of fractures in postmenopausal females diagnosed with primary osteoporosis (strong recommendation; high-certainty evidence).

RECOMMENDATION 1B

ACP suggests that clinicians use bisphosphonates for initial pharmacologic treatment to reduce the risk of fractures in males diagnosed with primary osteoporosis (conditional recommendation; low-certainty evidence).

RECOMMENDATION 2A

ACP suggests that clinicians use the RANK ligand inhibitor (denosumab) as a second-line pharmacologic treatment to reduce the risk of fractures in postmenopausal females diagnosed with primary osteoporosis who have contraindications to or experience adverse effects of bisphosphonates (conditional recommendation; moderate-certainty evidence).

RECOMMENDATION 2B

ACP suggests that clinicians use the RANK ligand inhibitor (denosumab) as a second-line pharmacologic treatment to reduce the risk of fractures in males diagnosed with primary osteoporosis who have contraindications to or experience adverse effects of bisphosphonates (conditional recommendation; low-certainty evidence).

RECOMMENDATION 3

ACP suggests that clinicians use the sclerostin inhibitor (romosozumab, moderate-certainty evidence) or recombinant PTH (teriparatide, low-certainty evidence), followed by a bisphosphonate, to reduce the risk of fractures only in females with primary osteoporosis with very high risk of fracture (conditional recommendation).

RECOMMENDATION 4

ACP suggests that clinicians take an individualized approach regarding whether to start pharmacologic treatment with a bisphosphonate in females over the age of 65 with low bone mass (osteopenia) to reduce the risk of fractures (conditional recommendation; low-certainty evidence).

Effectiveness and Safety of Treatments to Prevent Fractures in People With Low Bone Mass or Primary Osteoporosis: A Living Systematic Review and Network Meta-analysis for the American College of Physicians

BACKGROUND

The prevalence of osteoporosis is increasing in the United States.

PURPOSE

To evaluate low bone mass and osteoporosis treatments to prevent fractures.

DATA SOURCES

Ovid MEDLINE ALL, Ovid Evidence Based Medicine Reviews: Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and ClinicalTrials.gov from 2014 through February 2022.

STUDY SELECTION

Adults receiving eligible interventions for low bone mass or osteoporosis. Randomized controlled trials (RCTs) for fracture outcomes, and RCTs and large observational studies (n ≥1000) for harms.

DATA EXTRACTION

Abstracted by 1 reviewer and verified by a second. Independent, dual assessments of risk of bias and certainty of evidence (CoE).

DATA SYNTHESIS

We included 34 RCTs (in 100 publications) and 36 observational studies. Bisphosphonates and denosumab reduced hip, clinical and radiographic vertebral, and other clinical fractures in postmenopausal females with osteoporosis (moderate to high CoE). Bisphosphonates for 36 months or more may increase the risk for atypical femoral fractures (AFFs) and osteonecrosis of the jaw (ONJ), but the absolute risks were low. Abaloparatide and teriparatide reduced clinical and radiographic vertebral fractures but increased the risk for withdrawals due to adverse events (WAEs; moderate to high CoE). Raloxifene and bazedoxifene for 36 months or more reduced radiographic vertebral but not clinical fractures (low to moderate CoE). Abaloparatide, teriparatide, and sequential romosozumab, then alendronate, may be more effective than bisphosphonates in reducing clinical fractures for 17 to 24 months in older postmenopausal females at very high fracture risk (low to moderate CoE). Bisphosphonates may reduce clinical fractures in older females with low bone mass (low CoE) and radiographic vertebral fractures in males with osteoporosis (low to moderate CoE).

LIMITATION

Few studies examined participants with low bone mass, males, or Black-identifying persons, sequential therapy, or treatment beyond 3 years.

CONCLUSION

Bisphosphonates, denosumab, abaloparatide, teriparatide, and romosozumab, followed by alendronate, reduce clinical fractures in postmenopausal females with osteoporosis. Abaloparatide and teriparatide increased WAEs; longer duration bisphosphonate use may increase AFF and ONJ risk though these events were rare.

PRIMARY FUNDING SOURCE

American College of Physicians. (PROSPERO: CRD42021236220).

Improvement in Glucocorticoid-Induced Osteoporosis on Switching from Bisphosphonates to Once-Weekly Teriparatide: A Randomized Open-Label Trial

This randomized, open-label, multicenter, parallel study imitating real-world clinical practice assessed the effect of switching to weekly teriparatide in patients with glucocorticoid-induced osteoporosis (GIO) with a lumbar spine/proximal femur bone mineral density (BMD) T-score ≤ -2.0 or ≤-1.0 and a fragility fracture. Forty-four patients were randomized. The mean durations of the corticosteroid and bisphosphonate administrations were 90.0 and 51.3 months. The baseline BMD at L1-L4 was 0.828 and 0.826 g/cm² in Groups B (bisphosphonate) and T (teriparatide); at the femur (total), these values were 0.689 and 0.661 g/cm². The mean change in BMD was numerically higher with teriparatide vs. bisphosphonate but not statistically significant. The mean percentage changes from baseline in BMD at L1-L4 after a 72-week treatment were 0.5% and 4.1% in Groups B and T. The incidence of new fractures was higher in the patients taking bisphosphonates vs. those receiving once-weekly teriparatide at 72 weeks (18.2% vs. 11.8%) and 144 weeks (22.7% vs. 17.6%). The mean percentage change in femur (trochanter) BMD (0.035 [0.007-0.063]; p = 0.02) was significantly greater with teriparatide vs. bisphosphonates. Adverse events (AEs) were more frequent with teriparatide vs. bisphosphonates. Switching to once-weekly teriparatide tended to increase lumbar spine BMD and reduce the occurrence of new fractures vs. bisphosphonates.

Expansion of the osteocytic lacunar-canalicular system involved in pharmacological action of PTH revealed by AI-driven fluorescence morphometry in female rabbits

Osteoporosis is an age-related disorder that is characterized by reduced bone mass. Its prevention and treatment are important healthcare issues for maintaining social activity in aged societies. Although bone fractures mostly occur at sites of weakened cortical bone, pathophysiological and pharmacological evaluations of bone mass have tended to be predominantly assessed in trabecular bone. To statistically characterize cortical bone remodeling, we originally established multimode fluorescence imaging and artificial intelligence (AI)-driven morphometric analyses in six-month-old female rabbits with well-defined cortical remodeling, similar to that in humans. We evaluated three distinct administration frequencies of teriparatide [TPTD; human parathyroid hormone, hPTH (1–34)]: once (1/w), twice (2/w), and seven times (7/w) a week, with the same total dose (140 μg/kg/week). Our analyses revealed significant expansions of the osteocytic lacunar-canalicular system and Haversian canals accompanied by the development of cortical porosity and endosteal naïve bone formation induced by a frequent administration regimen (7/w) of TPTD; however, once-weekly (1/w) and twice-weekly (2/w) administration of TPTD showed little effect. These findings demonstrate a clear contrast between the effects of frequent and infrequent administration of TPTD on cortical bone metabolism and suggest that osteocytic bone remodeling is involved in the pharmacological action of PTH.

Translucent Zone Between Autograft and Endplate Two Months Postoperatively Is an Independent Predictor of Delayed Osseous Union in Elderly Patients With Posterior Lumbar Interbody Fusion Surgery

Background Delayed union or pseudoarthrosis after posterior lumbar interbody fusion (PLIF) is associated with poor outcomes in health-related quality of life. Therefore, it is important to achieve earlier solid fusion for a successful clinical outcome after PLIF. A few authors reported that biomechanical factors may influence spinal fusion rates. The purpose of our retrospective study was to evaluate the independent predictors of delayed osseous union related to intraoperative procedures of PLIF, and to find ways to reduce delayed osseous union. Methods This was a retrospective study of a completed trial. We reviewed 66 elderly patients with osteoporosis after PLIF (all female, mean age 71 years, follow-up period over 6 months). Lumbar computed tomography scans at 2 months postoperatively were examined for the presence of a translucent zone between autograft and endplate (more than 50% of vertebral diameter), and autograft position with bone bridging (anterior, central, or posterior). Osseous union was assessed by using computed tomography 6 months postoperatively. Results Thirty-three patients (50%) showed complete osseous union, while 33 did not. A translucent zone between autograft and endplate two months postoperatively was observed in nine patients (27%) in the union group and in 23 (70%) in the nonunion group (p<0.01). Autograft position with bone bridging two months postoperatively was anterior, central, and posterior in 17 (52%), 30 (91%), and 20 patients (61%) in the union group, and in 12 (36%), 20 (61%), and seven patients (21%) in the nonunion group (p=0.22, p<0.01, and p<0.01), respectively. Multivariate logistic regression analysis showed that the presence of a translucent zone between autograft and endplate (odds ratio, 0.101; 95% confidence interval: 0.026-0.398; p<0.01) and teriparatide administration (odds ratio, 8.810; 95% confidence interval: 2.222-34.936; p<0.01) were independently associated with osseous union after PLIF. Conclusions A translucent zone between autograft and endplate at two months postoperatively independently predicted delayed osseous union within six months after PLIF. Complete osseous union rates were higher in patients with posterior bone bridging two months postoperatively than in those without. These findings apart from preoperative predictors of osseous union might serve as indicators of how intraoperative techniques affects osseous union enhancement.

Real-world persistence of twice-weekly teriparatide and factors associated with the discontinuation in patients with osteoporosis

INTRODUCTION

A 28.2 μg twice-weekly formulation of teriparatide (2/W-TPD) was developed to provide comparably high efficacy for osteoporosis to a 56.5 μg once-weekly formulation while improving the safety and persistence rate. In the current study, we aimed to elucidate the real-world persistence of 2/W-TPD and to identify the factors associated with the discontinuation of 2/W-TPD in patients with severe osteoporosis.

MATERIALS AND METHODS

This retrospective study included 90 patients who were treated with 2/W-TPD at three hospitals in Japan. Patient information was collected, including age, sex, distance to the hospital, family structure, comorbidities, previous treatment for osteoporosis, timing of the injection, side effects and duration of 2/W-TPD treatment, barthel index (BI), and bone mineral density (BMD) of the lumbar spine and femoral neck. We examined the factors influencing 2/W-TPD discontinuation using the Cox proportional hazards model.

RESULTS

The 12 month completion rate of 2/W-TPD therapy was 47.5%. The Cox hazard analysis identified side effects [Hazard Ratio (HR) = 14.59, P < 0.001], low BMD of the femoral neck (HR = 0.04, P = 0.002), and morning injection (HR = 3.29, P = 0.006) as risk factors influencing the discontinuation of 2/W-TPD. Other variables, including age, did not contribute to the continuation of 2/W-TPD.

CONCLUSION

One year continuation rate of 2/W-TPD was higher than the previously reported value of the once-weekly formulation in real-world setting, probably due to the lower incidence of side effects. Introducing injection of 2/W-TPD may further improve the persistence of TPD therapy for osteoporosis.

Histological functions of parathyroid hormone on bone formation and bone blood vessels

BACKGROUND

The intermittent administration of parathyroid hormone (PTH) has been prescribed to osteoporotic patients due to its bone anabolic effects. In addition to its actions on bone cells, PTH appears to affect bone-specific blood vessels. These blood vessels are derived from bone marrow sinusoids, which express EphB4, a hallmark of veinous vascular endothelial cells. Given the presence of osteo-vascular interactions, it is important to elucidate the effects of PTH on bone cells and blood vessels in murine models.

HIGHLIGHTS

PTH stimulates preosteoblastic proliferation and osteoblastic bone formation. The former appears to be directly affected by PTH, whereas the latter requires osteoclast-mediated coupling. The administration of PTH through high-frequency dosage schemes accelerates bone turnover featuring remodeling-based bone formation, whereas low-frequency schemes cause mainly remodeling-based and partly modeling-based bone formation. Normally, many blood vessels lack alpha smooth muscle actin (αSMA)-immunoreactive vascular muscle cells surrounding basement membranes, indicating them being capillaries. However, PTH administration increases the number of blood vessels surrounded by αSMA-positive cells. These αSMA-positive cells spread out of blood vessels and express alkaline phosphatase and c-kit, suggesting their potential to differentiate into osteogenic and vascular endothelial/perivascular cells. Unlike bone cells, αSMA-positive cells did not appear in the periphery of blood vessels in the kidney and liver, and the thickness of the tunica media did not change regardless of PTH administration.

CONCLUSION

Based on the results of the study and presence of osseous-vascular interactions, PTH appears to influence not only osteoblastic cells, but also blood vessels in bone.

Randomized controlled trial of daily teriparatide, weekly high-dose teriparatide, or bisphosphonate in patients with postmenopausal osteoporosis: The TERABIT study

PURPOSE

The effects of daily teriparatide (20 μg) (D-PTH), weekly high-dose teriparatide (56.5 μg) (W-PTH), or bisphosphonates (BPs) on areal bone mineral density (aBMD), bone turnover markers (BTMs), volumetric BMD (vBMD), microarchitecture, and estimated strength were investigated in postmenopausal osteoporosis patients.

METHODS

The study participants were 131 women with a history of fragility fractures. They were randomized to receive D-PTH, W-PTH, or BPs (alendronate or risedronate) for 18 months. Dual-energy X-ray absorptiometry (DXA), BTMs, and high-resolution peripheral quantitative CT (HR-pQCT) parameters were evaluated at baseline and after 6 and 18 months of treatment. The primary endpoint was the change (%) in cortical thickness (Ct.Th) after 18 months' treatment compared with baseline.

RESULTS

DXA showed that D-PTH, W-PTH, and BPs increased lumbar spine aBMD (+12.0%, +8.5%, and +6.8%) and total hip aBMD (+3.0%, +2.1%, and +3.0%), but D-PTH and W-PTH decreased 1/3 radius aBMD (-4.1%, -3.0%, -1.4%) after 18 months. On HR-pQCT, D-PTH increased trabecular vBMD (Tb.vBMD) at the distal radius and tibia after 18 months (+6.4%, +3.7%) compared with the BPs group, decreased cortical volumetric tissue mineral density (Ct.vTMD) (-1.8%, -0.9%) compared with the other groups, increased Ct.Th (+1.3%, +3.9%), and increased failure load (FL) (+4.7%, +4.4%). W-PTH increased Tb.vBMD (+5.3%, +1.9%), maintained Ct.vTMD (-0.7%, +0.2%) compared with D-PTH, increased Ct.Th (+0.6%, +3.6%), and increased FL (+4.9%, +4.5%). The BPs increased Tb.vBMD only in the radius (+2.0%, +0.2%), maintained Ct.vTMD (-0.6%, +0.3%), increased Ct.Th (+0.5%, +3.4%), and increased FL (+3.9%, +2.8%).

CONCLUSIONS

D-PTH and W-PTH comparably increased Ct.Th, the primary endpoint. D-PTH had a strong effect on trabecular bone. Although D-PTH decreased Ct.vTMD, it increased Ct.Th and total bone strength. W-PTH had a moderate effect on trabecular bone, maintained Ct.vTMD, and increased Ct.Th and total bone strength to the same extent as D-PTH.

Mechanism and efficacy of parathyroid hormone in osteoporosis

Background: Parathyroid hormone (PTH) and teriparatide, which is a PTH analog, are special options of osteoanabolic therapies for osteoporosis treatment. Their efficacy in improving the bone mineral density (BMD) and reducing fracture risk is considered to have a long-awaited justification.Current Concepts: PTH is an 84-amino acid polypeptide that plays a key role in the calcium homeostasis of the human body. It yields anabolic effects on the bone by intermittent injections. During the first 6 months of PTH treatment, bone formation increases rapidly and bone resorption rises gradually. PTH is believed to be maximally anabolic during the anabolic window. In the phase III trial of teriparatide, significant reductions in vertebral and non-vertebral fractures were identified. Teriparatide has been studied in drug-induced osteoporosis, postmenopausal women with osteoporosis, and men with osteoporosis. The data derived from clinical trials with teriparatide showed an increase of the BMD in the treatment group compared to that of the placebo. Selective advantages on fracture healing have been shown in some studies; however, consensus on the relationship between teriparatide and bone healing is unclear.Discussion and Conclusion: Teriparatide has been approved for osteoporosis treatment in various situations, including postmenopausal women, men with osteoporosis, and cases with glucocorticoid-induced osteoporosis. Additionally, it can be useful in high risk for fracture groups, if fractures persist despite bone resorption inhibitor therapy, and if bone resorption inhibitor administration is difficult and contraindicated.

Histological and histomorphometric aspects of continual intermittent parathyroid hormone administration on osseointegration in osteoporosis rabbit model

In implant treatment, primary stability and osseointegration are improved by continual intermittent administration of parathyroid hormone (PTH) in patients with osteoporosis. However, the histological and histomorphometric aspects are not clear. The aim of this study was to investigate the histological and histomorphometric effects of intermittent PTH administration on osseointegration in a glucocorticoid-induced osteoporotic rabbit model. Fifteen female New Zealand rabbits were prepared for the osteoporosis model with ovariectomy and glucocorticoid administration. After 1 week, five rabbits were intermittently administered PTH for 8 weeks until the end point (PTHa group) and five for 4 weeks until implant placement (PTHb group). The remaining rabbits were intermittently administered saline for 8 weeks until the end point (Control group). Dental implants were inserted into the femoral epiphyses 11 weeks after ovariectomy. After 4 weeks, the maximum removal torque (RT) of the placed implant and bone implant contact (BIC) ratio were evaluated. In addition micro-computed tomography and histomorphometric analyses were performed. The RT and BIC values were significantly higher in the PTHa group compared with those of the PTHb and Control groups (p< 0.05). Furthermore, the bone mineral densities and Hounsfield units were significantly higher in the PTHa group than those in the PTHb and Control groups. Histologic and histomorphometric measurements revealed that continuous administration of PTH improved bone density and bone formation around the implant placement site, as well as systemic bone formation. Therefore, favorable implant stability was achieved under osteoporosis.

Effect of adjuvant therapy with teriparatide in patients with thoracolumbar osteoporotic vertebral fractures who underwent vertebroplasty with posterior spinal fusion

Teriparatide (TPTD) administration has a potent osteogenic action and promotes the healing of osteoporotic vertebral fractures (OVFs). We aimed to investigate the outcomes of vertebroplasty with posterior spinal fusion (VP + PSF) and determine the impact of perioperative TPTD administration. We included 73 patients (18 male and 55 female patients; mean age: 78 years) with thoracolumbar OVFs who underwent VP + PSF and were followed-up for at least 2 years. Twenty-three patients who received TPTD perioperatively for > 3 months were included in the TPTD group, and the remaining 50 patients were included in the non-TPTD group. Radiographic findings regarding sagittal alignment and clinical outcomes in both groups were compared. The mean duration of TPTD administration was 17.5 ± 5.0 months (range 4–24 months). The mean loss of correction of local kyphosis angle in the TPTD group (4.0°) was lesser than that in the non-TPTD group (7.5°; p < 0.05); however, no significant differences were observed between the groups regarding global sagittal alignment, the occurrence of subsequent vertebral fractures, pedicle screw loosening and treatment-efficacy rates of clinical outcomes. Local kyphosis correction in patients who underwent VP + PSF for OVFs could be maintained through perioperative TPTD administration; however, TPTD administration had little effect on clinical outcomes.

The Relationship between the Drug Delivery Properties of a Formulation of Teriparatide Microneedles and the Pharmacokinetic Evaluation of Teriparatide Administration in Rats

PURPOSE

Teriparatide is an effective drug for the treatment of osteoporosis. This study examines the relationship between the drug delivery properties of the solid formulation with teriparatide and the pharmacokinetic properties of teriparatide in vivo.

METHODS

Teriparatide microneedles with different dissolution rates were prepared using sucrose and carboxymethylcellulose (CMC). There were three aspects of this study: (1) The dissolution rate of teriparatide from both formulations (sucrose and CMC) was measured in vitro. (2) After administration into porcine skin ex vivo, the diffusion rate of FITC-dextran was observed using a confocal microscope. (3) Pharmacokinetic studies were performed in rats and pharmacokinetic data compared with the release rate and the diffusion pattern.

RESULTS

In the in vitro dissolution experiment, 80% of teriparatide was released within 30 min from the CMC MNs, whereas 80% of teriparatide was released within 10 min from the sucrose MNs. After 30 min, the fluorescence intensity on the surface of the MNs was 40% of the initial intensity for sucrose MNs and 90% for CMC MNs. In the pharmacokinetic study, the C_max values of the CMC and sucrose MNs were 868 pg/mL and 6809 pg/mL, respectively, and the AUC_last values were 6771 pg*hr/mL for the CMC MNs and 17,171 pg*hr/mL for the sucrose MNs.

CONCLUSIONS

When teriparatide is delivered into the skin using microneedles, the release rate from the solid formulation determines the drug's pharmacokinetic properties. The diffusion pattern of fluorescence into the skin can be used to anticipate the pharmacokinetic properties of the drug.

Drug therapy for osteoporosis in older adults

The goal of osteoporosis management is to prevent fractures. Several pharmacological agents are available to lower fracture risk, either by reducing bone resorption or by stimulating bone formation. Bisphosphonates are the most widely used anti-resorptives, reducing bone turnover markers to low premenopausal concentrations and reducing fracture rates (vertebral by 50-70%, non-vertebral by 20-30%, and hip by ~40%). Bisphosphonates bind avidly to bone mineral and have an offset of effect measured in months to years. Long term, continuous use of oral bisphosphonates is usually interspersed with drug holidays of 1-2 years, to minimise the risk of atypical femoral fractures. Denosumab is a monoclonal antibody against RANKL that potently inhibits osteoclast development and activity. Denosumab is administered by subcutaneous injection every 6 months. Anti-fracture effects of denosumab are similar to those of the bisphosphonates, but there is a pronounced loss of anti-resorptive effect from 7 months after the last injection, which can result in clusters of rebound vertebral fractures. Two classes of anabolic drugs are now available to stimulate bone formation. Teriparatide and abaloparatide both target the parathyroid hormone-1 receptor, and are given by daily subcutaneous injection for up to 2 years. Romosozumab is an anti-sclerostin monoclonal antibody that stimulates bone formation and inhibits resorption. Romosozumab is given as monthly subcutaneous injections for 1 year. Head-to-head studies suggest that anabolic agents have greater anti-fracture efficacy and produce larger increases in bone density than anti-resorptive drugs. The effects of anabolic agents are transient, so transition to anti-resorptive drugs is required. The optimal strategy for cycling anabolics, anti-resorptives, and off-treatment periods remains to be determined.

Effects of teriparatide and low-intensity aerobic exercise on osteopenia in type 2 diabetes mellitus rats

INTRODUCTION

In patients with type 2 diabetes mellitus (T2DM), bone fragility increases fracture risk. Teriparatide (TPTD) improves bone strength, and exercise therapy suppresses blood glucose levels in T2DM. In this study, the combined effects of TPTD and exercise therapy on trabecular and cortical bone were examined in advanced T2DM model rats.

MATERIALS AND METHODS

Thirty-week-old Otsuka Long-Evans Tokushima Fatty rats were divided into four groups (n = 9-10 in each group at two time points): Cont group (vehicle-treated control), TPTD group (TPTD 30 μg/kg injected subcutaneously, 3 times/week), Exe group (treadmill exercise, 10 m/min, 60 min/day, 5 times/week), and Comb group (TPTD-treated and treadmill exercise combined). Five and 10 weeks after treatment, bone mineral density (BMD), bone strength, and bone micro-architecture were measured.

RESULTS

TPTD and combined treatment significantly increased BMDs of the lumbar spine and femur compared to the Cont group (p < 0.05 to p < 0.01). In the three-point bending test of the femur, only combined treatment increased the maximum load at 5 weeks compared with the Cont and Exe groups (p < 0.01). In the compression test of the distal femoral metaphysis, both TPTD and combined treatment increased the trabecular bone strength compared with the Cont and Exe groups (p < 0.05 to p < 0.01). Although TPTD and combined treatment improved the micro-architecture of trabecular bone (p < 0.05 to p < 0.01), only combined treatment improved the micro-structures of cortical bone from 5 weeks of treatment (p < 0.05 to p < 0.01).

CONCLUSION

The combination of TPTD and treadmill exercise increased BMD and trabecular and cortical bone strength of the femur with improved micro-architecture in T2DM model rats.

Pre-existing vertebral fracture is a risk factor for postoperative proximal junctional fracture after adult spinal deformity surgery: A propensity score-matched analysis

BACKGROUND

Corrective surgery for adult spinal deformity has recently been increasingly performed because of aging populations and advances in minimally invasive surgery. Low bone mineral density is a major contributor to proximal junctional kyphosis after spinal long fusion. Assessment for low bone mineral density ideally involves both dual energy X-ray absorptiometry and identification of pre-existing vertebral fractures, the latter, requiring only standard equipment, being performed more frequently. We therefore aimed to examine the impact of pre-existing vertebral fractures on the incidence of type 2 proximal junctional kyphosis, including proximal junctional fracture and failure, after corrective surgery for adult spinal deformity.

METHODS

We performed a retrospective, single institution study of 106 women aged over 50 years who had undergone corrective long spinal fusion for severely symptomatic spinal deformity from 2014 to 2017. We allocated them to three groups (with and without pre-existing vertebral fractures and with severe [Grades 2-3 according to Genant et al.'s classification] preexisting vertebral fractures) and used propensity score matching to minimize bias. The primary outcome was postoperative proximal junctional fracture and the secondary outcome proximal junctional kyphosis/failure.

RESULTS

The primary and secondary endpoints were achieved significantly more often in the 28 patients with than in the 78 without preexisting vertebral fractures (total 41). The former group was also significantly older and had greater pelvic tilt and fewer fused segments than those without vertebral fractures. After propensity score matching, the incidences of the endpoints did not differ with pre-existing vertebral fracture status; however, patients with severe vertebral fractures more frequently had proximal junctional fractures postoperatively. Postoperative improvements in health-related quality of life scores did not differ with pre-existing vertebral fracture status.

CONCLUSIONS

Severe pre-existing vertebral fractures are a risk factor for proximal junctional fracture after correction of adult spinal deformity.

A randomized, controlled trial of once-weekly teriparatide injection versus alendronate in patients at high risk of osteoporotic fracture: primary results of the Japanese Osteoporosis Intervention Trial-05

In this randomized, controlled trial, treatment with once-weekly subcutaneous injection of teriparatide for 72 weeks was found to be associated with a significant reduction in the incidence of morphometric vertebral fractures compared with alendronate in women with primary osteoporosis who were at high risk of fracture.

INTRODUCTION

To determine whether the anti-fracture efficacy of teriparatide is superior to that of alendronate, a prospective, randomized, open-label, blinded-endpoint trial was performed.

METHODS

Japanese women aged at least 75 years were eligible for the study if they had primary osteoporosis and were at high risk of fracture. Patients were randomly assigned in a 1:1 ratio to receive sequential therapy (once-weekly subcutaneous injection of teriparatide 56.5 μg for 72 weeks followed by alendronate for 48 weeks) or monotherapy with alendronate for 120 weeks. The primary endpoint was the incidence of morphometric vertebral fractures at 72 weeks (at the end of teriparatide treatment).

RESULTS

Between October 2014 and December 2017, 1011 patients (505 in the teriparatide group and 506 in the alendronate group) were enrolled. Of these, 778 patients (351 and 427, respectively) were included in the primary analysis. The incidence of morphometric vertebral fractures was significantly lower in the teriparatide group (56 per 419.9 person-years, annual incidence rate 0.1334) than in the alendronate group (96 per 553.6 person-years, annual incidence rate 0.1734), with a rate ratio of 0.78 (95% confidence interval 0.61 to 0.99, P = 0.04). In both groups, adverse events were most frequently reported in the following system organ classes: infections and infestations, gastrointestinal disorders, and musculoskeletal and connective tissue disorders.

CONCLUSION

Once-weekly subcutaneous injection of teriparatide significantly reduced the incidence of morphometric vertebral fractures compared with alendronate in women with primary osteoporosis who were at high risk of fracture.

TRIAL REGISTRATION

jRCTs031180235 and UMIN000015573, March 12, 2019.

Neoadjuvant teriparatide therapy targeting the osteoporotic spine: influence of administration period from the perspective of bone histomorphometry

OBJECTIVE

Teriparatide (TPTD) is a potent promoter of early-stage osteogenesis and may be a useful adjuvant therapy to reduce complications related to bone fragility in spinal surgery patients with osteoporosis. However, effective neoadjuvant TPTD therapy regimens remain poorly understood. This study aimed to examine the effect of preoperative TPTD administration on cancellous bone with bone histomorphometry and to clarify the timing of preoperative TPTD administration for patients with spinal fusion and osteoporosis.

METHODS

In this longitudinal multicenter study, 57 patients with spinal fusion and osteoporosis, who consented to undergo iliac biopsy, were allocated to the following treatment groups: neoadjuvant TPTD therapy group (n = 42) and no neoadjuvant therapy (NTC) group (n = 15). Patients in the TPTD group were categorized into subgroups on the basis of duration of preoperative TPTD administration, as follows: 1 month (n = 9), 2 months (n = 8), 3 months (n = 9), 4 months (n = 7), and 6 months (n = 9). All patient samples were preoperatively double labeled with tetracycline, and iliac biopsies were performed during spinal fusion surgery. Histomorphometric analyses were performed on nondecalcified, thin-sliced specimens. Specimens were classified on the basis of TPTD administration duration and subsequently compared with those of the NTC group. Postoperative complications and Oswestry Disability Index scores were evaluated at 1 and 2 years after surgery.

RESULTS

There were no demographic differences between groups. Mineralizing surface/bone surface, a key parameter of dynamic bone formation, started to increase after 1 month of TPTD administration; this increase became significant after 3 months of administration and peaked at 4 months, with a 6-fold increase relative to that of the NTC group. The patients who received preoperative TPTD for 3 months or more had superior clinical results in terms of the osteoporotic complication rate and Oswestry Disability Index scores, except for bisphosphonate-pretreated patients.

CONCLUSIONS

When considering neoadjuvant TPTD therapy, the authors recommend at least 3 months of preoperative administration to provide a more substantial anabolic effect from the early postoperative stage.

Exogenous parathyroid hormone attenuates ovariectomy-induced skeletal muscle weakness in vivo

Osteoporosis commonly affects the elderly and is associated with significant morbidity and mortality. Loss of bone mineral density induces muscle atrophy and increases fracture risk. However, muscle lipid content and droplet size are increased by aging and mobility impairments, inversely correlated with muscle function, and a cause of reduced motor function. Teriparatide, the synthetic form of human parathyroid hormone (PTH) 1-34, has been widely used to treat osteoporosis. Although PTH positively affects muscle differentiation in vitro, the precise function and mechanisms of muscle mass and power preservation are still poorly understood, especially in vivo. In this study, we investigated the effect of PTH on skeletal muscle atrophy and dysfunction using an ovariectomized murine model. Eight-week-old female C57BL/6J mice were ovariectomized or sham-operated. Within each surgical group, the mice were divided into PTH injection or control subgroups. Motor function was evaluated based on grip strength, treadmill running, and lactic acid concentration. PTH receptor was expressed in skeletal muscle cells and myoblasts. PTH inhibited ovariectomy-induced bone loss but not uterine atrophy or increased body weight; PTH not only abolished ovariectomy-induced reduction in grip strength and maximum running speed, but also significantly reduced the ovariectomy-induced increase in lactic acid concentration (compared with that observed in the vehicle control). PTH also abrogated the ovariectomy-induced reduction in the oxidative capacity of muscle fibers, their cross-sectional area, and intramyocellular lipid content, and induced cell proliferation, cell migration, and muscle differentiation, while reducing lipid secretion by C2C12 myoblasts via the Wnt/β-catenin pathway. PTH significantly ameliorated muscle weakness and attenuated exercise-induced lactate levels in ovariectomized mice. Our in vitro study demonstrated that PTH/Wnt signaling regulated the proliferation, migration, and differentiation of myoblasts and also reduced lipid secretion in myoblasts. Thus, PTH could regulate several aspects of muscle function and physiology, and may represent a novel therapeutic strategy for patients with osteoporosis.

Once-weekly parathyroid hormone combined with ongoing long-term alendronate treatment promotes osteoporotic fracture healing in ovariectomized rats

This study examined the effect of once-weekly parathyroid hormone (PTH) combined with alendronate upon osteoporotic fracture healing after long-term alendronate anti-osteoporosis therapy. Seventy-six 12-week-old female Sprague-Dawley rats were either sham operated or bilaterally ovariectomized (OVX). Following confirmation of osteoporosis 3 months after OVX, the remaining 64 animals received alendronate therapy. After 3 months of alendronate treatment, all rats underwent unilateral transverse tibial osteotomy. Animals were immediately randomly assigned to one of four groups: (1) alendronate followed by vehicle (ALN-VEH), (2) continuation of alendronate (ALN-ALN), (3) alendronate followed by once-weekly PTH alone (ALN-PTH), (4) continuation of alendronate combined with once-weekly PTH (ALN-ALN + PTH) until collection at 4 or 8 weeks after osteotomy. The fractured tibia was assessed using x-ray, dual-energy x-ray absorptiometry, microcomputed tomography, biomechanical testing, histology, and sequential fluorescence labeling. The ALN-ALN + PTH treatment significantly increased total callus volume, mineralized callus volume, mineralized callus volume/total callus volume, and biomechanical strength of the callus relative to ALN-VEH and ALN-PTH treatments at both 4 and 8 weeks and produced more mature trabecular bone compared with ALN-ALN treatment at 8 weeks. RANKL/osteoprotegerin (OPG) are osteoclastogenesis markers, while cluster of differentiation 31 (CD31) is an important marker of angiogenesis. Qualitative immunohistochemical analysis revealed that CD31 and OPG expression was was strong after ALN-ALN + PTH compared with ALN-ALN treatment, whereas RANKL expression was weak after ALN-ALN + PTH versus ALN-PTH treatment. Our study showed that once-weekly PTH combined with alendronate was beneficial in promoting the healing of fractures acquired after long-term alendronate therapy in OVX-induced osteoporotic rats.