Primary osteoporosis in men: an unmet medical need

Metabolic shifts in ratio of ucOcn to cOcn toward bone resorption contribute to age-dependent bone loss in male mice

The study of the senile osteoporosis in men still lags significantly behind that in women. The changes of protein molecule levels and their relationships with bone loss remain poorly understood. In the present study, we used C57BL/6J male mice at ages from 3 to 24 mo to delineate the mechanisms of aging effects on bone loss. We used the microcomputed tomography, mechanical testing, histomorphometry assays, and detection of serum levels of undercarboxylated osteocalcin (ucOcn) and carboxylated osteocalcin (cOcn) to assess bone mass changes and their relationships with the ratios of ucOcn-to-cOcn in mice from different age groups. The results showed that mouse trabecular bone mass reduced gradually with age, whereas cortical bone loss and mechanical property changes mostly occurred in advanced age. Our findings further demonstrated that the increase in osteoclast activity and the decrease in osteoblast function were significantly corelated with blood levels of ucOcn and cOcn, respectively. The dynamic metabolic changes of ucOcn to cOcn ratio were correlated with age-dependent bone loss in mice. In summary, metabolic shifts in the ratio of ucOcn to cOcn toward bone resorption from young adult to elderly mice contribute to the pathogenesis of age-related bone loss. Simultaneously monitoring blood ratios of ucOcn-to-cOcn may be useful to predict the status of bone mass in vivo.NEW & NOTEWORTHY To our knowledge, our finding in this study shows for the first time that metabolic shifts in ratio of ucOcn to cOcn toward bone resorption are markedly correlated with age-dependent bone loss in male mice. These findings for the effects of aging on bone loss will assist in studying the pathogenesis of human type II osteoporosis.

Efficacy of Xianling Gubao capsule vs. its combination therapy in the treatment of primary osteoporosis: A network meta-analysis of randomized controlled trials

Objective

This study aimed to evaluate the efficacy of the Xianling Gubao (XLGB) capsule alone and its combination therapy in primary osteoporosis (POP).

Methods

Databases including PubMed, Embase, Cochrane Library, Web of Science, CNKI, Wanfang Data, VIP, and SinoMed were searched from their inception to January 16, 2024, for randomized controlled trials (RCTs) investigating the XLGB treatment for POP. A network meta-analysis (NMA) was performed to evaluate the efficacy and safety of multiple interventions in the treatment of POP. The Cochrane risk-of-bias tool was used to assess the quality of RCTs included in the meta-analysis. Software Stata (version 15.0) was used for statistical analysis. The surface under the cumulative ranking curve (SUCRA) method was used to present the findings from this NMA numerically and graphically by ranking multiple interventions.

Results

A total of 107 RCTs were included in the meta-analysis, involving 10,032 participants and 21 interventions. Meta-analysis showed that XLGB + calcium (Ca) + calcitonin (99.9 %) was the most desirable treatment option for improving clinical efficacy. XLGB + Ca + bisphosphonate (BP) was most effective for improving bone mineral density (BMD) at the lumbar spine, femoral neck BMD, and serum bone Gla protein (BGP). SUCRA values for improving these three outcome measures by XLGB + Ca + BP were 87.4 %, 77.2 %, and 84.3 %, respectively. XLGB + calcitonin was the optimal option in terms of safety evaluation and improving visual analogue scale (VAS), with the SUCRA values being 89.6 % and 94.9 %, respectively.

Conclusions

The XLGB combination therapy is a desirable option for treating POP as it can effectively improve the therapeutic effects, BMD, and serum BGP, as well as relieve pain in patients with POP.

Subcutaneous testosterone pellet therapy for reversal of male osteoporosis: a review and case report

PURPOSE

To describe the effects of consistent levels of testosterone in a pellet form and it's potential to reverse osteoporosis.

METHODS

This is a descriptive case report of a 54 year male with a spontaneous fracture and osteoporosis in the presence of what many consider a normal male testosterone level.

RESULTS

After discovering and documenting osteoporosis by DXA scan, the patient was shown to reverse the diagnosis of osteoporosis in a year on pelleted testosterone therapy. Consistent levels of 943 ng/dL were achieved; the patient also experienced improvements in quality of life and sleep apnea.

CONCLUSION

Testosterone deficiency (TD) is a clinical syndrome and osteoporosis can be found in levels above standard "criteria" of 300. This patient did not realize a benefit on injections both physical and clinically and both improved on pelleted testosterone. This should be further studied and considered for TD in men.

Health belief model - male osteoporosis: a cross-sectional study

OBJECTIVES

The aim of this study is to examine the knowledge levels, beliefs, and self-efficacies of men regarding osteoporosis according to the health belief model.

METHODS

Men aged 55 years and older were included in the study. After the descriptive characteristics of the participants were recorded, the Male Osteoporosis Knowledge Quiz, Osteoporosis Health Belief Scale, Osteoporosis Self-Efficacy Scale, and Osteoporosis Knowledge Test were administered to the participants face-to-face.

RESULTS

A total of 435 men with an average age of 67.3 ± 0.4 years participated in the study. When the participants were categorized according to age subgroups, it was found that marital status (p = 0.002), economic status (p = 0.016), and education level (p < 0.001) differed with age. The results of the osteoporosis-specific measurement tools used in data collection also differed with age (p < 0.05). It was observed that men's levels of osteoporosis knowledge decreased with increasing age (p < 0.05). The lowest scores for the exercise benefits and health motivation subdimensions of the Osteoporosis Health Belief Scale and the Osteoporosis Self-Efficacy Scale were obtained from the subgroup that included the oldest participants (p < 0.05). The highest scores for the calcium barriers subdimension of the Osteoporosis Health Belief Scale were obtained from younger participants (p = 0.036). The level of osteoporosis knowledge showed a low-to-moderate correlation with each question of the Osteoporosis Health Belief Scale (p < 0.05). Age, education, associating the role of physiotherapy with primary-secondary treatment approaches, and health beliefs were the factors that affected the osteoporosis knowledge levels of the participating men (p < 0.05).

CONCLUSIONS

The knowledge of osteoporosis and preventive beliefs and behaviours of men need to be increased. Knowledge and perceptions of susceptibility to osteoporosis should be developed in men with appropriate education from an early age. We recommend that exercise and physiotherapy approaches should be utilized to a greater extent, especially for individuals in the at-risk age range.

Aberrant expression of miR-33a-3p/IGF2 in postmenopausal osteoporosis patients and its role and mechanism in osteoporosis

BACKGROUND

Postmenopausal osteoporosis (PMOP), the most frequent bone-related disease, is characterized by bone loss and fragile fractures, which is related to low bone density (BMD). This study aimed to illustrate the expression and mechanism of miR-33a-3p in osteoporosis.

METHODS

TargetScan and luciferase reporter assay were applied for verifying the relevance between miR-33a-3p and IGF2. Levels of miR-33a-3p, IGF2, Runx2, ALP and Osterix were checked using RT-qPCR and western blotting. hBMSCs proliferation, apoptosis and ALP activity were analyzed by MTT, flow cytometry (FCM) analysis and ALP detection kit, respectively. Moreover, the calcification of cells was assessed using Alizarin Red S staining. The average BMD was evaluated by dual-energy X-ray absorptiometry (DEXA) assay.

RESULTS

IGF2 was a target of miR-33a-3p. The level of miR-33a-3p was substantially higher and IGF2 expression was memorably lower in the serum of osteoporosis patients than that in healthy volunteers. Our results also pointed out that miR-33a-3p was reduced and IGF2 expression was enhanced during osteogenic differentiation. We concluded that miR-33a-3p negatively regulated the level of IGF2 in hBMSCs. Besides, miR-33a-3p mimic inhibited the osteogenic differentiation of hBMSCs via inhibiting the level of Runx2, ALP and Osterix and decreasing ALP activity. IGF2 plasmid dramatically reversed the influence of miR-33a-3p mimic on IGF2 expression, hBMSCs proliferation and apoptosis, and osteogenic differentiation of hBMSCs.

CONCLUSION

miR-33a-3p affected osteogenic differentiation of hBMSCs by targeting IGF2, indicating a potential use of miR-33a-3p as plasma biomarker and therapeutic target for postmenopausal osteoporosis.

Bone Mineral Density Reference Values in 18- to 95-Year-Old Population in Lombardy Region, Italy

The aim of this study is to assess the bone mineral density (BMD) and T-score reference values in a population from 18 to 95 years old in Lombardy region, Italy. This study also investigates the association between BMD values and body mass index (BMI) divided by gender and age. The evaluation of BMD was analyzed by T-score and BMD in each site, femur, and column. A total of 10,503 patients (9,627 females and 876 males, 65.04±12.18 years) have been enrolled in this study. The women hip femur reference values associated with a situation of osteopenia highlighted in-line with the class of age of 45 to 55 years were: mean values: -1.3132 T-score; 95% confidence interval (CI): -1.3600 to -1.2664 and of osteoporosis from the class of age 85 to 95 years, mean values: -2.6591 T-score, 95% CI: -2.7703 to -2.5479. The men hip femur reference values associated with a situation of osteopenia highlighted in-line with the class of age of 45 to 55 years were: mean values: 1.2986 T-score; 95% CI: -1.5454 to -1.0518. A positive association between BMI and the two sites of BMD was recorded (p > .05). This study provides an Italian overview of national and regional reference values about the BMD and T-score values divided by age and gender as reference values for clinicians for a correct assessment and monitoring.

Ginsenoside Rb1 prevents osteoporosis via the AHR/PRELP/NF-κB signaling axis

BACKGROUND

Accumulating clinical and experimental evidence shows multiple biological effects of ginsenoside Rb1 (GRb1) in the treatment of aging related diseases such as osteoporosis (OP). Recently, GRb1 has attracted extensive attention as an anti-osteoporosis agent. Here, we sought to identify the mechanism by which GRb1 improves OP.

METHODS

A dexamethasone (DEX)-induced rat model of OP was constructed and the rats were treated with GRb1 to examine its role in OP. We screened the action targets of GRb1 online and validated by performing functional experiments. The correlation between aryl hydrocarbon receptor (AHR) and proline/arginine-rich end leucine-rich repeat protein (PRELP) was identified through luciferase and chromatin immunoprecipitation assays. In the isolated osteoblasts from DEX-induced OP rats, the expression of osteogenic differentiation-associated genes, and nuclear factor-kappa B (NF-κB) pathway-related genes, mineralization, and number of calcium nodules were assessed.

RESULTS

GRb1 enhanced the differentiation of osteoblasts, the mechanism of which was related to upregulation of AHR. AHR could promote the transcription of PRELP by binding to the PRELP promoter region and consequently caused its upregulation. Meanwhile, PRELP inhibited the activation of the NF-κB pathway, which underlay the promoting impact of AHR in the osteogenic differentiation. Additionally, GRb1 could ameliorate OP in DEX-induced rats via the AHR/PRELP/NF-κB axis.

CONCLUSIONS

Our findings demonstrate that GRb1 might function as an effective candidate to prevent the progression of OP via regulation of the AHR/PRELP/NF-κB axis, revealing a new molecular mechanism underpinning the impact of GRb1 in the progression of OP and offering a theoretical contribution to the treatment of OP.

Physiological testosterone replacement effects on male aged rats with orchiectomy-induced osteoporosis in advanced stage: a tomographic and biomechanical pilot study

Aim: This study aimed to evaluate the effect of physiological testosterone replacement on male aged rats with orchiectomy-induced osteoporosis in advanced stage.Methods: Thirty male rats (Rattus norvegicus albinus, Holtzman lineage) were randomly distributed into 3 groups (n = 10): 1-sham, 2-orchiectomy (OCX), 3-OCX + testosterone replacement (OCX + T). On day 0, a sham or orchiectomy surgery was performed according to the groups. Thirty and sixty days after surgeries, the animals from OCX + T group received testosterone intramuscularly, and the rats in all groups were euthanized on day 77. The femurs were removed for micro-CT scanning and biomechanical test.Results: Orchiectomy resulted in a marked trabecular bone damage (p < 0.05), which was not reversed with testosterone treatment (OCX + T group). The femoral strength was lower in orchiectomized animals (p < 0.05), while the bone strength in OCX + T group was similar to that observed in the sham animals (p > 0.05) and correlated to this parameter the deformation of rupture was smaller in OCX + T group.Conclusion: In conclusion, testosterone depletion induced by orchiectomy established an osteoporotic environment, mainly affecting the trabecular bone. Moreover, even though testosterone treatment did not enhance these variables, the hormonal replacement improved the femoral fracture strength and promoted beneficial effects on the biomechanical parameters compromised by castration in femoral bone.

Long non-coding RNA RP11-84C13.1 promotes osteogenic differentiation of bone mesenchymal stem cells and alleviates osteoporosis progression via the miR-23b-3p/RUNX2 axis

The objective of the present study was to determine the role of RP11-84C13.1 in osteoporosis (OP) and its molecular mechanism. First, clinical samples were collected from OP patients and normal control patients. Human bone marrow stromal cells (hBMSCs) were extracted from femoral head tissues. Runt-related transcription factor 2 (RUNX2) and RP11-84C13.1 serum levels were assessed by reverse transcription-quantitative (RT-q)PCR. Following transfection of pcDNA-RP11-84C13.1, si-RP11-84C13.1, microRNA (miRNA)-23b-3p mimic and miRNA-23b-3p inhibitor, the expression levels of RUNX2 and RP11-84C13.1 were determined by RT-qPCR. In addition, the osteogenic ability of hBMSCs was assessed by Alizarin Red staining. The binding of RP11-84C13.1 to miRNA-23b-3p and the binding of miRNA-23b-3p to RUNX2 was confirmed by dual-luciferase reporter gene assay. Long non-coding RNA (lncRNA) RP11-84C13.1 was significantly downregulated in the serum of OP patients. The osteogenic differentiation-related genes RUNX2 and RP11-84C13.1 were markedly upregulated in a time-dependent manner, while the miRNA-23b-3p level gradually decreased in hBMSCs with the prolongation of osteogenesis. RP11-84C13.1 knockdown inhibited the osteogenic differentiation of hBMSCs. Furthermore, RP11-84C13.1 regulated RUNX2 expression by targeting miRNA-23b-3p. Overexpression of miRNA-23b-3p partially reversed the promoting effect of RP11-84C13.1 on the osteogenesis of hBMSCs. In conclusion, lncRNA RP11-84C13.1 upregulated RUNX2 by absorbing miRNA-23b-3p, and thus induced hBMSC osteogenesis to alleviate osteoporosis.

Strontium ranelate incorporated 3D porous sulfonated PEEK simulating MC3T3-E1 cell differentiation

Polyetheretherketone (PEEK) has been used as an implant material because it has similar mechanical properties to natural bone. However, inferior osseointegration and bioinertness hamper the clinical application of PEEK. In this study, the surfaces of sulfonated three-dimensional (3D) PEEK porous structures were loaded with different concentrations of strontium ranelate, a compound commonly used in the treatment or prevention of osteoporosis by promoting bone formation and inhibiting bone resorption. Field-emission scanning electron microscopy was used to characterize the topography of the structures, elemental carbon, oxygen and strontium contents were measured by X-ray photoelectron spectroscopy, and surface zeta potentials and water-contact angle were also measured. The results indicated that strontium ranelate was successfully loaded onto the 3D porous structures. In vitro cellular results showed that strontium ranelate-treated sulfonated PEEK (SP-SR) strengthened the adhesion of MC3T3-E1 cells. The activity of alkaline phosphatase, collagen secretion and extracellular matrix mineralization deposition of MC3T3-E1 cells were also improved on the surface of SP-SR. These results indicate that SP-SR could serve a new implant candidate for surgical treatment.

Macrophage Polarization and Osteoporosis: A Review

Over 200 million people suffer from osteoporosis worldwide. Individuals with osteoporosis have increased rates of bone resorption while simultaneously having impaired osteogenesis. Most current treatments for osteoporosis focus on anti-resorptive methods to prevent further bone loss. However, it is important to identify safe and cost-efficient treatments that not only inhibit bone resorption, but also stimulate anabolic mechanisms to upregulate osteogenesis. Recent data suggest that macrophage polarization may contribute to osteoblast differentiation and increased osteogenesis as well as bone mineralization. Macrophages exist in two major polarization states, classically activated macrophages (M1) and alternatively activated macrophage (M2) macrophages. The polarization state of macrophages is dependent on molecules in the microenvironment including several cytokines and chemokines. Mechanistically, M2 macrophages secrete osteogenic factors that stimulate the differentiation and activation of pre-osteoblastic cells, such as mesenchymal stem cells (MSC’s), and subsequently increase bone mineralization. In this review, we cover the mechanisms by which M2 macrophages contribute to osteogenesis and postulate the hypothesis that regulating macrophage polarization states may be a potential treatment for the treatment of osteoporosis.