Clinical Application of Teriparatide in Fracture Prevention: A Systematic Review

Association between P1NP and bone strength in postmenopausal women treated with teriparatide

OBJECTIVE

To evaluate the association between P1NP and bone strength in postmenopausal women treated with teriparatide.

MATERIALS AND METHODS

This prospective study enrolled 248 postmenopausal women with severe osteoporosis treated with teriparatide. Procollagen type 1 N-terminal propeptide (P1NP) were assessed at baseline, 3, 6, and 12 months. Lumbar spine (LS), femoral neck (FN), and total hip (TH) bone mineral density (BMD) and LS trabecular bone score (TBS) were measured by Dual-energy x-ray absorptiometry at baseline and 12 months.

RESULTS

With teriparatide use, P1NP levels increase and peaked at 6 months. Significant increase in LS and hip BMD and LS TBS were also noted. The percentage change or absolute change >10 μg/L in PINP at 3 months was only related to changes in LS BMD at 12 months. With a median baseline P1NP level was 65.5 ng/mL, we found no correlation between P1NP and LS and hip BMD nor LS TBS. There was no association between LS TBS and axial BMD. After treatment, there was also no significance between the changes in TBS and axial BMD. Over the study period, 83.9% of the 248 participants were persistent with teriparatide at 3 months, 77.8% at 6 months, and 67.3% women at 12 months.

CONCLUSION

P1NP levels may provide a signal of osteoporosis risk but is not related to bone strength. Early changes in P1NP may offer information regarding subsequent BMD response so standardized monitoring of P1NP levels at baseline and at 3 months should be considered during osteoporosis therapy. As an additional benefit, serum level monitoring during treatment may also improve medication persistence.

The role of intermittent PTH administration in conjunction with allogenic stem cell treatment to stimulate fracture healing

Aims

A growing number of fractures progress to delayed or nonunion, causing significant morbidity and socioeconomic impact. Localized delivery of stem cells and subcutaneous parathyroid hormone (PTH) has been shown individually to accelerate bony regeneration. This study aimed to combine the therapies with the aim of upregulating fracture healing.

Methods

A 1.5 mm femoral osteotomy (delayed union model) was created in 48 female juvenile Wistar rats, aged six to nine months, and stabilized using an external fixator. At day 0, animals were treated with intrafracture injections of 1 × 10⁶ cells/kg bone marrow mesenchymal stem cells (MSCs) suspended in fibrin, daily subcutaneous injections of high (100 μg/kg) or low (25 μg/kg) dose PTH 1-34, or a combination of PTH and MSCs. A group with an empty gap served as a control. Five weeks post-surgery, the femur was excised for radiological, histomorphometric, micro-CT, and mechanical analysis.

Results

Combination therapy treatment led to increased callus formation compared to controls. In the high-dose combination group there was significantly greater mineralized tissue volume and trabecular parameters compared to controls (p = 0.039). This translated to significantly improved stiffness (and ultimate load to failure (p = 0.049). The high-dose combination therapy group had the most significant improvement in mean modified Radiographic Union Score for Tibia fractures (RUST) compared to controls (13.8 (SD 1.3) vs 5.8 (SD 0.5)). All groups demonstrated significant increases in the radiological scores – RUST and Allen score – histologically compared to controls.

Conclusion

We demonstrate the beneficial effect of localized MSC injections on fracture healing combined with low- or high-dose teriparatide, with efficacy dependent on PTH dose.

Cite this article: Bone Joint Res 2021;10(10):659–667.

Combined effect of teriparatide and an anti-RANKL monoclonal antibody on bone defect regeneration in mice with glucocorticoid-induced osteoporosis

OBJECTIVE

The purpose of this study was to examine the effect of single or combination therapy of teriparatide (TPTD) and a monoclonal antibody against the murine receptor activator of nuclear factor κB ligand (anti-RANKL Ab) on cancellous and cortical bone regeneration in a mouse model of glucocorticoid-induced osteoporosis (GIOP).

METHODS

C57BL/6 J mice (24 weeks of age) were divided into five groups: (1) the SHAM group: sham operation + saline; (2) the prednisolone (PSL) group: PSL + saline; (3) the TPTD group: PSL + TPTD; (4) the Ab group: PSL + anti-RANKL Ab; and (5) the COMB group: PSL + TPTD + anti-RANKL Ab (n = 8 per group). With the exception of the SHAM group, 7.5 mg of PSL was inserted subcutaneously into mice, to generate a mouse model of GIOP. Four weeks after insertion, bone defects with a diameter of 0.9 mm were created to assess bone regeneration on both femoral metaphysis (cancellous bone) and diaphysis (cortical bone). After surgery, therapeutic intervention was continued for 4 weeks. Saline (200 μl) or TPTD (40 μg/kg) was injected subcutaneously five times per week, whereas the anti-RANKL Ab (5 mg/kg) was injected subcutaneously once on the day after surgery. Subsequently, the following analyses were performed: microstructural assessment of bone regeneration and bone mineral density (BMD) measurement via micro-computed tomography, and histological, histomorphometrical, and biomechanical analyses with nanoindentation.

RESULTS

The COMB group showed the highest lumbar spine BMD increase (vs. the PSL, TPTD, and Ab groups). The volume of regenerated cancellous bone at the bone defect site was higher in the COMB group compared with the PSL, TPTD, and Ab group. The volume of the regenerated cortical bone was significantly higher in the COMB group compared with the PSL group, and its hardness was significantly higher in the COMB group compared with the PSL and TPTD groups.

CONCLUSION

In a mouse model of glucocorticoid-induced osteoporosis, the combination therapy of TPTD plus the anti-RANKL Ab increased bone mineral density in the lumbar spine and regenerated cancellous bone volume compared with single administration of each agent, and also increased regenerated cortical bone strength compared with single administration of TPTD.

Comparison between teriparatide and bisphosphonates for improving bone mineral density in postmenopausal osteoporosis patients: A meta-analysis

BACKGROUND

We performed a systematic review and meta-analysis of the efficacy and safety of teriparatide and bisphosphonates in managing postmenopausal osteoporosis.

METHODS

PubMed, EMBASE, Web of Science, and China National Knowledge Infrastructure were searched for relevant randomized controlled trials that were published before April 2018 and compared teriparatide and bisphosphonates in treating postmenopausal osteoporosis. Stata 12.0 was used for the meta-analysis. The pooled risk ratio (RR) or weighted mean difference and 95% confidence interval (CI) were calculated using a fixed effects or random effects meta-analysis.

RESULTS

A total of 14 randomized controlled trials were included in this meta-analysis. The teriparatide group was associated with a lower total occurrence of vertebral fractures (RR = 0.55, 95% CI: 0.40-0.77; P = .001) and nonvertebral fractures (RR = 0.65, 95% CI: 0.46-0.90; P = .009) than the bisphosphonate group. Moreover, compared with the bisphosphonate group, the teriparatide group had improved bone mineral density at the lumbar spine and femoral neck at the final follow-up (P < .05). There was no significant difference between the teriparatide and bisphosphonate groups in terms of complications (RR = 1.05, 95% CI: 0.90, 1.22, P = .516).

CONCLUSIONS

Teriparatide significantly reduced the occurrence of vertebral and nonvertebral fractures in osteoporosis patients. More studies should focus on the quality of life of patients using these 2 drugs.