Journal of Bone and Mineral Metabolism最新文献

Introduction: To identify predictors of discontinuing treatment with teriparatide (TPTD) and alendronate (ALN), data from a randomized, controlled trial (JOINT-05) involving postmenopausal Japanese women at high risk of fracture were re-analyzed.

Materials and methods: Participants received sequential therapy with once-weekly TPTD for 72 weeks followed by ALN for 48 weeks (TPTD-ALN group) or monotherapy with ALN for 120 weeks (ALN group). Background data including comorbidities, fracture prevalence, cognitive function, quality of life, activities of daily living, bone metabolism parameters, and nutrient intake were collected. The endpoints were 3 types of discontinuations by the reason: a poor compliance, adverse events (AEs), or any reason including those unrelated to AEs or poor compliance. Odds ratios (ORs) of baseline predictors of discontinuation were evaluated by single or multiple regression analysis.

Results: A total of 234 (49.0%) patients in the TPTD-ALN group and 167 (34.2%) patients in the ALN group discontinued. In the TPTD-ALN group, a lower serum calcium level was a significant predictor of compliance-related discontinuation. Serum 25-hydroxyvitamin D levels were lower in patients with lower serum calcium levels than with higher serum calcium levels. In the ALN group, poor cognitive function was significantly associated with compliance-related discontinuation, and higher body mass index and alcohol intake were predictors of AE-related discontinuation. Predictors of discontinuation were drug-specific. Lower serum calcium levels and poor cognitive function were predictors of discontinuing once-weekly TPTD and ALN, respectively.

Conclusion: When starting TPTD and ALN treatment, careful attention to patients with lower serum calcium levels and poor cognitive function, respectively, may be needed for better treatment continuity.

Introduction: Disulfiram (DSF), known as an anti-alcoholism drug, has been reported to suppress osteoclast differentiation in vitro; however, it remains uncertain whether DSF is effective in preventing osteoclastogenesis in vivo. This study aimed to investigate the effect of DSF administration in osteoporotic mice and its contribution to osteoclastogenesis in vivo.

Materials and methods: The bone phenotype of ovariectomized mice, both treated and untreated with DSF, was examined using microcomputed tomography analysis. Osteoclastic and osteoblastic parameters were assessed through bone morphometric analysis. The direct effect of DSF on osteoblastogenesis in vitro was evaluated via a primary osteoblast culture experiment. The expression of genes related to DSF targets (Nup85, Ccr2, and Ccr5) in osteoclast-lineage cells was examined using scRNA-seq analysis and flow cytometry analysis using the bone marrow cells from ovariectomized mice. The impact of DSF on osteoclast-lineage cells was assessed using primary cultures of osteoclasts.

Results: DSF administration ameliorated ovariectomy-induced bone loss and mitigated the increase of osteoclasts without affecting osteoblastogenesis. The scRNA-seq data revealed that osteoclast precursor cells expressed Nup85, Ccr2, and Ccr5. CCR2 and CCR5-positive cells in osteoclast precursor cells within bone marrow increased following ovariectomy, and this increase was canceled by DSF administration. Finally, we found that DSF had a significant inhibitory effect on osteoclastogenesis in the early stage by suppressing Tnfrsf11a expression.

Conclusion: This study demonstrates that DSF could be a candidate for osteoporosis therapies because it suppresses osteoclastogenesis from an early stage in vivo.

Hedgehog and canonical Wnt signaling pathways and the transcription factors Runx2 and Sp7 are essential for osteoblast differentiation. Ihh is necessary for the commitment of perichondrial mesenchymal cells to Runx2⁺ osteoprogenitors and for the formation of the bone collar and primary spongiosa. Runx2 is needed for osteoblast differentiation during both endochondral and intramembranous ossification. It regulates the commitment of mesenchymal cells to osteoblast-lineage cells and their proliferation by inducing the expression of Hedgehog, Fgf, Wnt, Pthlh signaling pathway genes, and Dlx5. The Runx2-induced expression of Fgfr2 and Fgfr3 is important for the proliferation of osteoblast-lineage cells. Runx2 induces Sp7 expression and Runx2⁺ osteoprogenitors become Runx2⁺Sp7⁺ preosteoblasts. Runx2, Sp7, and canonical Wnt signaling induce the differentiation of preosteoblasts into osteoblasts. Canonical Wnt signaling, but not Sp7, enhances the proliferation of osteoblast-lineage cells. In mature osteoblasts, Runx2 plays an important role in the expression of major bone matrix protein genes, including Col1a1, Col1a2, Spp1, Ibsp, and Bglap/Bglap2. The canonical Wnt signaling pathway is also crucial for bone formation by mature osteoblasts. Sp7 is needed for osteocytes to acquire a sufficient number of processes and a reduction in these processes results in osteocyte apoptosis and cortical porosity.

Introduction: The association between serum vitamin D levels and bone mineral density (BMD) varies by race and gender. This study aimed to evaluate this relationship between serum vitamin D levels and BMD, and changes of BMD over time in Korean women.

Materials and methods: We analyzed data from 586 generally healthy Korean women aged 29-79 who underwent health check-ups at Seoul National University Gangnam Center between 2010 and 2011 (baseline measurement) and 2015-2016 (follow-up). Dual energy X-ray absorptiometry (DEXA) and serum 25-hydroxyvitamin D (25OH-D) level measurements were conducted. We assessed the association between serum 25OH-D levels and BMD, as well as changes in BMD over time.

Results: The mean age of participants was 51.3 ± 7.9 years, with a mean follow-up interval of 4.6 ± 0.7 years, and mean serum 25OH-D level of 20.6 ± 8.5 ng/ml. Baseline serum 25OH-D levels did not correlate with BMD values at the lumbar spine, femoral neck, or total femur, nor with changes in BMD over time. A significant negative association was found between perimenopausal status and BMD changes at all sites, and between premenopausal status and lumbar bone mass, compared to postmenopausal status in the 25OH-D < 20 ng/ml group. This association was not observed in women with higher serum 25OH-D levels.

Conclusions: Serum 25OH-D levels did not correlate with BMD levels or changes in BMD overall. However, in late reproductive-aged and perimenopausal women with serum 25OH-D insufficiency, there was a significant association with accelerated bone loss.

Introduction

Monitoring of bone mineral density (BMD) is used to assess pharmacological osteoporosis therapy. This study examined the real-life effects of antiresorptive and osteoanabolic treatments on volumetric BMD (vBMD) of the spine by quantitative computed tomography (QCT).

Materials and Methods

Patients aged ≥ 50 years with a vBMD < 120 mg/ml had ≥ 2 QCT. For analysis of therapy effects, the pharmacological treatment and the duration of each therapy were considered. Identical vertebrae were evaluated in all vBMD measurements for each patient. A linear mixed model with random intercepts was used to estimate the effects of pharmacological treatments on vBMD.

Results

A total of 1145 vBMD measurements from 402 patients were analyzed. Considering potential confounders such as sex, age, and prior treatment, a reduction in trabecular vBMD was estimated for oral bisphosphonates (− 1.01 mg/ml per year; p < 0.001), intravenous bisphosphonates (− 0.93 mg/ml per year; p = 0.015) and drug holiday (− 1.58 mg/ml per year; p < 0.001). Teriparatide was estimated to increase trabecular vBMD by 4.27 mg/ml per year (p = 0.018). Patients receiving denosumab showed a statistically non-significant decrease in trabecular vBMD (− 0.44 mg/ml per year; p = 0.099). Compared to non-treated patients, pharmacological therapy had positive effects on trabecular vBMD (1.35 mg/ml; p = 0.001, 1.43 mg/ml; p = 0.004, 1.91 mg/ml; p < 0.001, and 6.63 mg/ml; p < 0.001 per year for oral bisphosphonates, intravenous bisphosphonates, denosumab, and teriparatide, respectively).

Conclusion

An increase in trabecular vBMD by QCT was not detected with antiresorptive agents. Patients treated with teriparatide showed increasing trabecular vBMD. Non-treatment led to a larger decrease in trabecular vBMD than pharmacological therapy.

Graphical abstract

Wnt signaling plays an important role in the regulation of bone metabolism. Wnt activates the β-catenin-mediated canonical pathway and β-catenin-independent non-canonical pathway. When Wnt ligands bind to the co-receptors low density lipoprotein receptor-related protein (Lrp)5 or Lrp6, and a seven-transmembrane receptor frizzled, the canonical pathway is activated. On the other hand, when Wnt ligands bind to the receptor complex consisting of the co-receptor receptor tyrosine kinase-like orphan receptor (Ror)1 and Ror2 or Ryk and frizzled, the non-canonical pathway is activated. An analysis of loss-of-function and gain-of-function mutations in molecules involved in Wnt signaling (ligands, receptors, and inhibitors) has revealed the mechanisms by which Wnt signaling regulates bone metabolism. In this review, based on transcriptome analyses of Wnt expression in bone tissues including single cell RNA sequence analysis and previous literatures, we herein introduce and discussed the latest findings on the mechanisms by which Wnt ligand mutations impair bone metabolism, especially bone formation.

Introduction

This study established normative references for total body less head (TBLH) BMD, lumbar spine (L1–L4) BMD, and both total and appendicular lean mass (LM) in Thai children and adolescents (aged 5–18 years) using DXA. This work expands upon 2014 normative data for Thai children, which included L2–L4 BMD, total body BMD (head included), and total LM.

Materials and methods

We reanalyzed total body and lumbar spine DXA scans (Lunar Prodigy Pro, GE Healthcare; enCORE version 7.53) from 174 boys and 193 girls, using upgraded software (enCORE version 17SP2) for TBLH BMD, L1–L4 BMD, and LM analysis. The “enhanced” mode was applied for TBLH BMD and LM. Adjustments for total and appendicular LM were made relative to squared height (m²) to account for body size variability.

Results

Normative data stratified by sex and Tanner stage were generated for TBLH BMD, L1–L4 BMD, and LM indices. Weight and Tanner stage significantly determined BMD and LM. Adolescent girls exhibited higher LSBMD values due to earlier pubertal onset. Boys showed higher LM indices with more rapid gains during growth spurts.

Conclusion

This study provides updated normative reference values for BMD (TBLH and L1–L4) and LM (total and appendicular) in Thai children and adolescents, measured via DXA. These references will enhance the assessment of low bone mass and LM deficits in Thai pediatric populations, particularly in those with chronic illnesses.

Introduction

The trabecular bone score (TBS) has emerged as a convenient measure for assessing the microstructure of trabecular bone in the second through fourth lumbar vertebrae (L2–4) and can be conducted concurrently with bone mineral density (BMD) assessment. This study was performed to evaluate changes in BMD and the TBS during ADT for prostate cancer.

Materials and Methods

Consecutive patients who had prostate cancer without bone metastases at Kobe University Hospital were studied from March 2020 to December 2021. BMD and TBS were measured every 6 months from the start of treatment using Hologic Horizon devices (Hologic, Inc., Marlborough, MA, USA).

Results

Thirty-four patients were followed for 2 years. Significant declines in BMD (−3.8% for femoral neck, −4.2% for total hip, and −6.1% for lumbar spine) and TBS (−16.6%) were noted after 2 years of ADT. Correlation analyses revealed a weak correlation between lumbar spine BMD and TBS at ADT initiation, but this correlation strengthened after 2 years. The multiple regression analysis results suggested that the rate of BMD loss may be slower in patients with a preserved pretreatment TBS.

Conclusion

In patients without bone metastases undergoing ADT for prostate cancer, notable decreases were found in both BMD and TBS over a 2-year treatment period. Factors influencing the TBS decline remain unclear; however, patients with a lower pretreatment TBS exhibited a more rapid decline in BMD.