Bisphosphonate and denosumab initiation in older adults in Ontario, Canada: a population-based cohort study

Targeting the PTN/PTPRZ1-ROS Pathway to Promote Bone Regeneration

Background: Osteoporosis is a global health problem that significantly decreases patients' quality of life and causes tremendous medical burdens. Therefore, exploring effective targeting strategies for osteoporosis treatment is crucial. Previous studies have indicated that pleiotrophin (PTN) was a secretory factor involved in several biological processes, such as angiogenesis, neural development, and abnormal osteogenic functions in osteoporosis. However, the roles of PTN in osteogenics and the mechanisms remain unclear. Methods: In this study, we explored the effects and mechanisms of PTN in regulating osteogenic functions using real-time quantitative PCR, immunofluorescence, ALP detection, a TUNEL assay, RNA sequencing, and phosphorylation quantitative proteomics. Fracture-healing experiments in osteoporosis rats were also conducted to evaluate the osteogenic functions of PTN in vivo. Results: We found that PTN significantly inhibited apoptosis and promoted the osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs). Further experiments showed that PTN regulated the biological functions of rBMSCs by promoting antioxidant functions and reducing cellular reactive oxygen species (ROS), thereby protecting rBMSCs from accumulated ROS. Additionally, we found that PTN binds to the PTPRZ1 receptor, inducing intracellular PLCG1 phosphorylation and NCOA3 nuclear translocation, which regulate the downstream antioxidant functions of rBMSCs. Additionally, we verified that PTN effectively promoted fracture healing in osteoporotic animals. Conclusions: This study elucidates the mechanisms by which PTN promotes osteogenesis and verifies this effect in vivo, offering an effective target for osteoporosis treatment.

Bioinformatics analysis of key genes and potential therapeutic agents for vascular calcification in chronic kidney disease

Vascular calcification is a common complication of chronic kidney disease (CKD). The molecular mechanisms underlying this condition and the efficacy of potential treatments remain unclear. Bioinformatic methods were employed to analyze gene ontology (GO) annotations and pathway enrichments. Subsequently, an analysis of potential therapeutic agents for vascular calcification in CKD was performed. A total of 76 common genes, 181 enriched GO annotations-comprising 153 biological processes, 10 cellular components, and 18 molecular functions-41 KEGG pathways, 13 REACTOME pathways, and 3 BIOCARTA pathways were identified. Five key genes (PSMC5, TNFSF11, TNFRSF11A, TNFRSF12A, and ICAM1) were isolated. Most notably, the top five potential therapeutic drugs-ENAVATUZUMAB, DENOSUMAB, ALICAFORSEN, BI-505, and ENLIMOMAB PEGOL-were identified for vascular calcification in CKD. However, further molecular biological experiments are required to confirm these findings.

Real-world evidence: new opportunities for osteoporosis research. Recommendations from a Working Group from the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO)

This narrative review summarises the recommendations of a Working Group of the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) for the conduct and reporting of real-world evidence studies with a focus on osteoporosis research.

PURPOSE

Vast amounts of data are routinely generated at every healthcare contact and activity, and there is increasing recognition that these real-world data can be analysed to generate scientific evidence. Real-world evidence (RWE) is increasingly used to delineate the natural history of disease, assess real-life drug effectiveness, understand adverse events and in health economic analysis. The aim of this work was to understand the benefits and limitations of this type of data and outline approaches to ensure that transparent and high-quality evidence is generated.

METHODS

A ESCEO Working Group was convened in December 2022 to discuss the applicability of RWE to osteoporosis research and approaches to best practice.

RESULTS

This narrative review summarises the agreed recommendations for the conduct and reporting of RWE studies with a focus on osteoporosis research.

CONCLUSIONS

It is imperative that research using real-world data is conducted to the highest standards with close attention to limitations and biases of these data, and with transparency at all stages of study design, data acquisition and curation, analysis and reporting to increase the trustworthiness of RWE study findings.

Hypocalcemia Risk of Denosumab Across the Spectrum of Kidney Disease: A Population-Based Cohort Study

Denosumab can be used in patients with chronic kidney disease (CKD) but has been linked with cases of severe hypocalcemia. The incidence of and risk factors for hypocalcemia after denosumab use are not well established. Using linked health care databases at ICES, we conducted a population-based cohort study of adults >65 years old with a new prescription for denosumab or a bisphosphonate between 2012 and 2020. We assessed incidence of hypocalcemia within 180 days of drug dispensing and stratified results by estimated glomerular filtration rate (eGFR in mL/min/1.73 m² ). We used Cox proportional hazards to assess risk factors for hypocalcemia. There were 59,151 and 56,847 new denosumab and oral bisphosphonate users, respectively. Of the denosumab users, 29% had serum calcium measured in the year before their prescription, and one-third had their serum calcium checked within 180 days after their prescription. Mild hypocalcemia (albumin corrected calcium <2.00 mmol/L) occurred in 0.6% (95% confidence interval [CI] 0.6, 0.7) of new denosumab users and severe hypocalcemia (<1.8 mmol/L) in 0.2% (95% CI 0.2, 0.3). In those with an eGFR <15 or receiving maintenance dialysis, the incidence of mild and severe hypocalcemia was 24.1% (95% CI 18.1, 30.7) and 14.9% (95% CI 10.1, 20.7), respectively. In this group, kidney function and baseline serum calcium were strong predictors of hypocalcemia. We did not have information on over-the-counter vitamin D or calcium supplementation. In new bisphosphonate users, the incidence of mild hypocalcemia was 0.3% (95% CI 0.3, 0.3) with an incidence of 4.7% (95% CI 1.5, 10.8) in those with an eGFR <15 or receiving maintenance dialysis. In this large population-based cohort, we found that the overall risk of hypocalcemia with new denosumab use was low but increased substantially in those with eGFR <15 mL/min/1.73 m² . Future studies should investigate strategies to mitigate hypocalcemia. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Clinical Management of Women with Newly Diagnosed Osteoporosis: Data from Everyday Practice in Bulgaria

INTRODUCTION

The real duration of osteoporosis treatment in clinical practice is still not well described. The primary objective is to estimate the proportion of patients who stayed on treatment during a 4-year follow-up, and the secondary objective is to estimate the proportion of patients who switched treatment and the reasons for switch or discontinuation.

METHODS

This was a national retrospective chart review, based on routine clinical data. Data were collected electronically from medical records in 33 representative primary care physicians' sites. Inclusion criteria were women with postmenopausal osteoporosis that have received initial treatment prescription following diagnosis by DXA between January 1, 2012 and December 31, 2014, and at least a 12-month database history after the index date. Exclusion criteria were women receiving treatment for osteoporosis and follow-up at secondary care physicians' sites only. All statistical analyses were performed with the R statistical package.

RESULTS

A total of 1206 female patients with newly diagnosed osteoporosis and treatment initiation were followed for 4 years. The majority (88.3%) had no history of previous fractures. Bone mineral density data were available in 70.1%. Endocrinology was the most common specialty among prescribing specialists (40.0%), followed by rheumatology (30.3%). Bisphosphonates (BPs) were the most common initial treatment (72.7%), followed by denosumab (20.1%). Ibandronate (70.2%) and alendronate (24.2%) constituted the majority of all prescribed BPs; 731 patients remained on treatment during the second year (60.6%), 524 during the third year (43.4%) and 403 (33.4%)-at study end (fourth year). In all groups, except that on denosumab, the most common reason for switching to another treatment was presumed lack of effect. The main reasons for treatment discontinuation were financial on the patient's part.

CONCLUSIONS

The duration of osteoporosis treatment in real-world clinical practice is far from optimal: < 3-4 years irrespective of fracture risk. Factors other than medical considerations are at play, mainly limitations set by the Health Insurance Fund. The health authorities should be aware of this.