Age and frailty as risk factors for the development of osteoarthritis

Identification of telomere-related diagnostic markers in osteoarthritis based on bioinformatics analysis and machine learning

Osteoarthritis (OA) is one of the most prevalent joint disorders, with aging considered a primary, irreversible factor contributing to its progression. Telomere-related cellular senescence may be a crucial factor influencing the OA process, yet biomarkers for OA based on telomere-related genes have not been clearly identified. The datasets GSE51588, GSE12021, and GSE55457 were retrieved from the Gene Expression Omnibus database. Initially, R software was utilized to identify differentially expressed genes between OA and normal samples. Subsequently, differentially expressed telomere-related genes (DETMRGs) were obtained, and their functional enrichment was analyzed. Feature genes for OA diagnosis were selected from DETMRGs using a combination of least absolute shrinkage and selection operator, support vector machine-recursive feature elimination, and Random Forest algorithms. The diagnostic value of these feature genes was then validated through receiver operating characteristic (ROC) curves and decision curve analysis. Additionally, CIBERSORT and xCell were employed to assess the infiltration of immune cells in OA tissues. Finally, potential drugs targeting candidate genes were predicted. Three telomere-related genes, PGD, SLC7A5, and TKT, have been identified as biomarkers for OA diagnosis and were confirmed through ROC diagnostic tests. The immune infiltration of mast cells, neutrophils, common lymphoid precursors, and eosinophils associated with PGD, SLC7A5, and TKT was reduced. Recognizing telomere-related genes PGD, SLC7A5, and TKT as potential diagnostic biomarkers for OA is significant, as it offers valuable insights into the role of telomere-related genes in OA. This discovery also provides valuable information for the diagnosis and treatment of OA.

Osteosarcopenia, osteoarthritis and frailty: a two-sample Mendelian randomization study

BACKGROUND

Musculoskeletal disease, which has a complicated relationship with frailty, is a common clinical problem among elderly individuals.

AIMS

This study evaluated the potential causal relationships between osteosarcopenia, osteoarthritis and frailty by Mendelian Randomization (MR) analysis.

METHODS

This study employed a two-sample MR approach to investigate the causal relationships among osteosarcopenia, osteoarthritis and frailty. Published summary statistics were used to obtain instrumental variables at the genome-wide significance level.

RESULTS

Among the age groups with osteoporosis, high total bone mineral density (TBMD) (45-60, OR = 0.966, 95% CI 0.940-0.993, P = 0.013) and TBMD (over 60, OR = 0.974, 95% CI 0.954-0.994, P = 0.011) reduced the risk of frailty. Similarly, high forearm BMD (FA-BMD), high ultradistal forearm BMD (UFA-BMD), and high Heel-BMD at different sites also reduced the risk of frailty (OR = 0.966, 95% CI 0.936-0.996, P = 0.028; OR = 0.975, 95% CI 0.953-0.997, P = 0.029; OR = 0.981, 95% CI 0.967-0.995, P = 0.008). Among the characteristics related to sarcopenia, grip strength in the left hand, grip strength in the right hand, appendicular lean mass, and walking pace were all protective factors for frailty (OR = 0.788, 95% CI 0.721-0.862, P < 0.001; OR = 0.800, 95% CI 0.737-0.869, P < 0.001; OR = 0.955, 95% CI 0.937-0.974, P = 0.000; OR = 0.480, 95% CI 0.388-0.593, P < 0.001), with low grip strength in those over 60 years of age significantly positively correlated with frailty (OR = 1.168, 95% CI 1.059-1.289, P = 0.002). The MR results of osteoarthritis and frailty revealed a causal relationship between specific joint sites and frailty, including KOA (OR = 1.086, 95% CI 1.017-1.160, P = 0.014), HOA (OR = 1.028, 95% CI 1.007-1.049, P = 0.009), and KOA/HOA (OR = 1.082, 95% CI 1.053-1.113, P = 0.000), increasing the risk of frailty.

CONCLUSION

Osteosarcopenia, osteoarthritis and frailty exhibit significant causal effects, rendering them risk factors for frailty. Therefore, in clinical practice, patients with osteosarcopenia and osteoarthritis should be required to undergo relevant interventions to reduce the risk of frailty.

Epidemiological trends and characteristics of osteoarthritis in China during 1990-2021

Background

This study aimed to comprehensively analyze the incidence, prevalence, and disability-adjusted life years (DALYs) of osteoarthritis (OA) in China from 1990 to 2021 by age, sex, joint sites, high body mass index (BMI) and sociodemographic index (SDI).

Methods

Data and methodologies from the Global Burden of Diseases (GBD) Study 2021 were obtained to evaluate the burden of OA in China. This assessment was conducted by estimating the number of incident cases, prevalent cases, DALYs, and corresponding age-standardized rates (ASRs). The estimated annual percentage change was employed to delineate the trends over time.

Results

In China, the number of OA incidence cases, prevalence cases, and DALYs increased to 11.65 million, 152.85 million and 5.33 million in 2021, respectively, exhibiting a consistent upward trend over the years. The ASRs of OA incidence, prevalence, and DALYs rose 13.86 %, 14.34 %, and 16.23 % from 1990 to 2021, respectively, with knee OA most affected. In 2021, OA incidence, prevalence, and DALYs were higher in women than in men, and increased with age for both sexes, peaking at ages 50-54 for incidence and 55-59 for prevalence and DALYs. DALYs of OA attributed to high BMI increased rapidly, and high BMI contributed to 21.64 % of the total age-standardized DALYs rate of OA in China. Positive correlations were observed between ASRs and China's SDI from 1990 to 2021.

Conclusion

OA constitutes a significant public health challenge in China, with a persistently high disease burden. There is a pressing need to enhance public understanding of the risk factors associated with OA and to promote preventive strategies to mitigate the future burden of this disorder.The translational potential of this article China has the largest elderly population and the highest prevalence of OA globally. Updating and analyzing epidemiological data of OA in China will offer the public, healthcare professionals, and policymakers the most current, comprehensive, and comparable information, which holds significant translational potential.

The Effect of Nerve Growth Factor on Cartilage Fibrosis and Hypertrophy during In Vitro Chondrogenesis Using Induced Pluripotent Stem Cells

Nerve growth factor (NGF) is a neurotrophic factor usually involved in the survival, differentiation, and growth of sensory neurons and nociceptive function. Yet, it has been suggested to play a role in the pathogenesis of osteoarthritis (OA). Previous studies suggested a possible relationship between NGF and OA; however, the underlying mechanisms remain unknown. Therefore, we investigated the impact of NGF in chondrogenesis using human induced pluripotent stem cells (hiPSCs)-derived chondrogenic pellets. To investigate how NGF affects the cartilage tissue, hiPSC-derived chondrogenic pellets were treated with NGF on day 3 of differentiation, expression of chondrogenic, hypertrophic, and fibrotic markers was confirmed. Also, inflammatory cytokine arrays were performed using the culture medium of the NGF treated chondrogenic pellets. As a result, NGF treatment decreased the expression of pro-chondrogenic markers by approximately 2~4 times, and hypertrophic (pro-osteogenic) markers and fibrotic markers were increased by approximately 3-fold or more in the NGF-treated cartilaginous pellets. In addition, angiogenesis was upregulated by approximately 4-fold or more, bone formation by more than 2-fold, and matrix metalloproteinase induction by more than 2-fold. These inflammatory cytokine array were using the NGF-treated chondrogenic pellet cultured medium. Furthermore, it was confirmed by Western blot to be related to the induction of the glycogen synthase kinase-3 beta (GSK3β) pathway by NGF. In Conclusions, these findings provide valuable insights into the multifaceted role of NGF in cartilage hypertrophy and fibrosis, which might play a critical role in OA progression.

The intersection of aging and estrogen in osteoarthritis

Osteoarthritis (OA) is a chronic joint disease characterized by cartilage degradation, inflammation, and pain. While multiple factors contribute to OA development, age and sex are primary risk factors, particularly affecting postmenopausal women. The dramatic increase in OA risk after menopause suggests estrogen deficiency accelerates disease progression. This review explores the molecular mechanisms connecting aging and estrogen deficiency in OA development, focusing on key genes and pathways identified through RNA sequencing.

Viral infections of the central nervous system increase the risk of knee osteoarthritis: a two-sample mendelian randomization study

OBJECTIVE

Osteoarthritis (OA) represents a condition under the influence of central nervous system (CNS) regulatory mechanisms. This investigation aims to examine the causal association between viral infections of the central nervous system (VICNS) and inflammatory diseases of the central nervous system (IDCNS) and knee osteoarthritis (KOA) at the genetic level.

METHODS

In this investigation, VICNS and IDCNS were considered as primary exposure variables, while KOA served as the primary outcome. Employing a two-sample mendelian randomization (MR) approach, we conducted an analysis utilizing summary data derived from genome-wide association studies (GWAS). The GWAS summary data pertaining to VICNS and IDCNS were procured from the Finnish consortium, whereas the IEU OpenGWAS database furnished the requisite data for KOA. To ensure the robustness of our genetic causal assessment, a comprehensive array of sensitivity analyses was undertaken, encompassing evaluations of heterogeneity, horizontal pleiotropy, outlier identification, leave-one-out analyses, and assessment of the normal distribution.

RESULTS

The results of the MR analyses revealed a suggestive positive genetic causal relationship between VICNS and KOA (P = 0.012, odds ratio [OR] with a 95% confidence interval [CI] of 1.033 [1.007-1.059]). Conversely, the MR analyses did not indicate any evidence of genetic causation between IDCNS and KOA (P = 0.575, OR 95% CI = 0.986 [0.940-1.035]). Importantly, the genetic causal assessment of the exposure and outcome variables did not demonstrate any indications of heterogeneity, horizontal pleiotropy, or outliers. Furthermore, this assessment remained robust against the influence of individual single nucleotide polymorphisms (SNPs) and exhibited adherence to a normal distribution.

CONCLUSION

The result of this study has elucidated a suggestive positive genetic causal link between the VICNS and KOA. However, no such genetic causal relationship was observed between the IDCNS and KOA. These findings substantiate the genetic underpinnings supporting the association between the CNS and OA.

Prevalence and location of myofascial trigger points in dogs with osteoarthritis

Introduction

This study was designed to determine the prevalence of myofascial pain and the location of myofascial trigger points (MTPs) in dogs with osteoarthritis.

Methods

Thirty-five dogs were selected and examined for the presence of MTPs using palpation. Assessments were performed independently by two examiners. Correlations between age, MTP number and location, and the site of osteoarthritis were also investigated.

Results and discussion

Thirty out of 35 dogs (86%) had at least one MTP and only 5 (14%) had none. A total of 177 MTPs were identified in dogs in this sample. The prevalence of MTPs was higher in the longissimus thoracicae (40% and 43%; left and right side respectively), followed by the quadriceps femoris (40% and 31%), longissimus lumborum (20% and 23%), gluteus medius and deltoid muscles (14%; left side only), and the pectineus muscle (11%; right side only). The number of osteoarthritic joints was not correlated with the number of MTPs or age. However, age was positively correlated with the number of muscles affected by MTPs. Correlations between the presence of MTPs in muscles surrounding and the affected joints were also lacking.

Conclusion

The prevalence of MTPs in dogs with osteoarthritis is high. Myofascial TPs are positively correlated with age in these patients. The subjective nature of palpation is a major limitation in myofascial pain assessment. Appropriate training and use of standardized diagnostic criteria are recommended.

Frailty and the incidence of surgical site infection after total hip or knee arthroplasty: A meta-analysis

BACKGROUND

Surgical site infection (SSI) remains a critical postoperative complication after total hip and knee arthroplasty (THA and TKA). Frailty, a condition characterized by decreased physiological reserve and increased vulnerability to stressors, may influence the risk of SSI in these patients. This meta-analysis aims to evaluate the association between frailty and the incidence of SSI following THA or TKA.

METHODS

A systematic search of databases including PubMed, EMBASE, Web of Science, Wanfang, and CNKI was conducted to identify relevant studies. Data were extracted and pooled using a random-effects model to calculate the overall risk ratio (RR) and 95 % confidence intervals (CIs).

RESULTS

A total of ten studies comprising 1,036,787 patients met the inclusion criteria. The meta-analysis revealed that frail patients undergoing THA or TKA had a significantly higher risk of developing SSI compared to non-frail patients (RR = 1.64, 95 % CI: 1.39-1.93, p < 0.001, I2 = 66 %). Subgroup analyses indicated that the type of arthroplasty (hip vs. knee) and the method of frailty assessment did not significantly alter the association. Further subgroup analysis suggested that frailty was significantly associated with a higher incidence of deep SSI including joint infection (RR = 1.77, 95 % CI: 1.27-1.48, p < 0.001), but not the incidence of superficial SSI (RR = 1.57, 95 % CI: 0.45-5.42, p = 0.48). The association between frailty and SSI remains in subgroup of multivariate studies only (RR = 1.56, 95 % CI: 1.34 to 1.80, p < 0.001).

CONCLUSIONS

Frailty is a potential predictor of SSI following TKA/THA.

ASA VI controls osteoarthritis in mice by maintaining mitochondrial homeostasis through Sirtuin 3

OBJECTIVE

The aim of this study was to investigate whether ASA VI controls osteoarthritis (OA) by regulating mitochondrial function.

METHODS

Primary chondrocytes were isolated and cultured from rat knee joints. The chondrocytes were treated with ASA VI and interleukin-1β (IL-1β) to simulate the inflammatory environment of OA. Cell viability, apoptosis, inflammatory cytokine levels, and extracellular matrix (ECM) component levels were assessed. Mitochondrial function, including ATP levels, mitochondrial membrane potential, reactive oxygen species (ROS) levels, and mitochondrial DNA content, was evaluated. The expression of Sirtuin 3 (Sirt3), a key regulator of mitochondrial homeostasis, was examined. Additionally, a rat OA model was established by destabilizing the medial meniscus, and the effects of ASA VI on cartilage degeneration were assessed.

RESULTS

ASA VI treatment improved cell viability, reduced apoptosis, and decreased IL-6 and TNF-α levels in IL-1β-induced chondrocytes. ASA VI also upregulated Collagen II and Aggrecan expression, while downregulating ADAMTS5 and MMP-13 expression. Furthermore, ASA VI mitigated IL-1β-induced mitochondrial dysfunction by increasing ATP levels, restoring mitochondrial membrane potential, reducing ROS production, and preserving mitochondrial DNA content. These effects were accompanied by the activation of Sirt3. In the rat OA model, ASA VI treatment increased Sirt3 expression and alleviated cartilage degeneration.

CONCLUSION

ASA VI exerts chondroprotective and anti-inflammatory effects on IL-1β-induced chondrocytes by improving mitochondrial function through Sirt3 activation. ASA VI also attenuates cartilage degeneration in a rat OA model. These findings suggest that ASA VI may be a potential therapeutic agent for the treatment of osteoarthritis by targeting mitochondrial dysfunction.

Investigating the shared genetic architecture of osteoarthritis and frailty: a genome-wide cross-trait analysis

Observational studies suggest a link between osteoarthritis (OA) and frailty, but the shared genetic architecture and causal relationships remain unclear. We analyzed X-ray and 18F-FDG PET/CT images in frail and non-frail individuals and conducted genetic correlation analyses using Linkage Disequilibrium Score Regression (LDSC) based on recent Genome-Wide Association Studies (GWAS) for OA and frailty. We identified pleiotropic single-nucleotide polymorphisms (SNPs) through Cross-Phenotype Association (CPASSOC) and Colocalization (COLOC) analyses and investigated genetic overlaps using Multi-marker Analysis of GenoMic Annotation (MAGMA). Transcriptome-wide association studies (TWAS) were conducted to analyze pleiotropic gene expression, and Mendelian Randomization (MR) was used to assess causal relationships between OA and frailty. Frail individuals showed more severe OA on X-ray (67% vs. 31%, P ≤ 0.01) and higher SUVmax on 18F-FDG PET/CT (4.1 vs. 3.6, P < 0.05) compared to non-frail individuals. Genetic correlation between frailty and OA was significant (rg = 0.532, P = 4.230E-88). Cross-trait analyses identified 42 genomic loci and 138 genes shared between the conditions. COLOC analysis revealed 2 pleiotropic loci, while TWAS identified 27 significant shared genetic expressions in whole blood and musculoskeletal tissue. Bidirectional MR indicated that OA increases the risk of frailty (IVW: beta: 0.13, P = 1.52E-08) and vice versa (IVW: beta: 0.73, P = 1.66E-04). Frail individuals exhibit more severe imaging features of OA. The shared genetic basis between OA and frailty suggests an intrinsic link, providing new insights into the relationship between these conditions.

Nanoparticle-delivered quercetin exhibits enhanced efficacy in eliminating iron-overloaded senescent chondrocytes

Aim: The therapeutic potential of senolytic drugs in osteoarthritis (OA) is poorly known. Quercetin, a senolytic agent exhibits promising potential to treat OA, having limited bioavailability. We investigated the effects of Quercetin-loaded nanoparticles (Q-NP) with enhanced bioavailability in human chondrocytes mimicking OA phenotype.Materials & methods: The C-20/A4 chondrocytes were exposed to ferric ammonium citrate to induce OA phenotype, followed by treatment with free Quercetin/Q-NP for 24 and 48-h. Q-NP were synthesized by nanoprecipitation method. Following treatment chondrocytes were assessed for drug cellular bioavailability, viability, cell cycle, apoptosis, oxidative stress and expression of key senescence markers.Results: Q-NP exhibited 120.1 ± 1.2 nm particle size, 81 ± 2.4% encapsulation efficiency, increased cellular bioavailability and selective apoptosis of senescent chondrocytes compared with free Quercetin. Q-NP treatment also induced oxidative stress and reduced the expressions of senescence markers, including TRB3, p16, p62 and p21 suggesting their ability to eliminate senescent cells. Last, Q-NP arrested the cell cycle in the sub-G0 phase, potentially creating a beneficial environment for tissue repair.Conclusion: Q-NP propose a promising delivery system for treating OA by eliminating senescent chondrocytes through apoptosis. Furthermore, their enhanced cellular bioavailability and capacity to modify cell cycle and senescent pathways warrant further investigations.

Therapeutic Potential of Olfactory Ensheathing Cells and Adipose-Derived Stem Cells in Osteoarthritis: Insights from Preclinical Studies

Olfactory-ensheathing cells (OECs) are known for their role in neuronal regeneration and potential to promote tissue repair. Adipose-derived stem cells (ADSCs), characterized by mesenchymal stem cell (MSC) traits, display a fibroblast-like morphology and express MSC surface markers, making them suitable for regenerative therapies for osteoarthritis (OA). In this study, OECs and ADSCs were derived from tissues and characterized for their morphology, surface marker expression, and differentiation capabilities. Collagenase-induced OA was created in 10-week-old C57BL/6 mice, followed by intra-articular injections of ADSCs (1 × 105), OECs (1 × 105), or a higher dose of OECs (5 × 105). Therapeutic efficacy was evaluated using rotarod performance tests, MRI, histology, and immunohistochemistry. Both cell types exhibited typical MSC characteristics and successfully differentiated into adipocytes, osteoblasts, and chondrocytes, confirmed by gene expression and staining. Transplantation significantly improved rotarod performance and preserved cartilage integrity, as seen in MRI and histology, with reduced cartilage destruction and increased chondrocytes. Immunohistochemistry showed elevated type II collagen and aggrecan in treated joints, indicating hyaline cartilage formation, and reduced MMP13 and IL-1β expression, suggesting decreased inflammation and catabolic activity. These findings highlight the regenerative potential of OECs and ADSCs in treating OA by preserving cartilage, promoting chondrocyte proliferation, and reducing inflammation. Further research is needed to optimize delivery methods and evaluate long-term clinical outcomes.

The role of monocyte/macrophage chemokines in pathogenesis of osteoarthritis: A review

Osteoarthritis (OA) is one of the most common degenerative diseases characterised by joint pain, swelling and decreased mobility, with its main pathological features being articular synovitis, cartilage degeneration and osteophyte formation. Inflammatory cytokines and chemokines secreted by activated immunocytes can trigger various inflammatory and immune responses in articular cartilage and synovium, contributing to the genesis and development of OA. A series of monocyte/macrophage chemokines, including monocyte chemotaxis protein (MCP)-1/CCL2, MCP2/CCL8, macrophage inflammatory protein (MIP)-1α/CCL3, MIP-1β/CCL4, MIP-3α/CCL20, regulated upon activation, normal T-cell expressed and secreted /CCL5, CCL17 and macrophage-derived chemokine/CCL22, was proven to transmit cell signals by binding to G protein-coupled receptors on recipient cell surface, mediating and promoting inflammation in OA joints. However, the underlying mechanism of these chemokines in the pathogenesis of OA remains still elusive. Here, published literature was reviewed, and the function and mechanisms of monocyte/macrophage chemokines in OA pathogenesis were summarised. The symptoms and disease progression of OA were found to be effectively alleviated when the expression of these chemokines is inhibited. Elucidating these mechanisms could contribute to further understand how OA develops and provide potential targets for the early diagnosis of arthritis and drug treatment to delay or even halt OA progression.

Molecular mechanisms of aging and anti-aging strategies

Aging is a complex and multifaceted process involving a variety of interrelated molecular mechanisms and cellular systems. Phenotypically, the biological aging process is accompanied by a gradual loss of cellular function and the systemic deterioration of multiple tissues, resulting in susceptibility to aging-related diseases. Emerging evidence suggests that aging is closely associated with telomere attrition, DNA damage, mitochondrial dysfunction, loss of nicotinamide adenine dinucleotide levels, impaired macro-autophagy, stem cell exhaustion, inflammation, loss of protein balance, deregulated nutrient sensing, altered intercellular communication, and dysbiosis. These age-related changes may be alleviated by intervention strategies, such as calorie restriction, improved sleep quality, enhanced physical activity, and targeted longevity genes. In this review, we summarise the key historical progress in the exploration of important causes of aging and anti-aging strategies in recent decades, which provides a basis for further understanding of the reversibility of aging phenotypes, the application prospect of synthetic biotechnology in anti-aging therapy is also prospected.

The genetic causal association between hip or knee osteoarthritis and frailty: a two-sample Mendelian randomization analysis

Introduction

Osteoarthritis of the hip or knee has been reported to be linked to an increased risk of frailty. However, a definitive conclusion about whether hip or knee osteoarthritis increases susceptibility to frailty remains elusive.

Material and methods

The instrumental variables (IVs) used in this analysis were sourced from publicly available genome-wide association study (GWAS) datasets. We used a two-sample Mendelian randomization analysis to evaluate the plausible causal nexus between hip or knee osteoarthritis and frailty.

Results

We included a total of 25 single-nucleotide polymorphisms (SNPs) as instrumental variables through rigorous and comprehensive screening. The results of this analysis suggested that hip or knee osteoarthritis is associated with an elevated risk of frailty. These results remained robust and consistent across multiple calculation methods, including inverse variance weighted (OR = 1.082, 95% CI: 1.0532-1.1125, p = 1.36 × 10-8), MR-Egger regression (OR = 1.175, 95% CI: 1.0162-1.3604, p = 0.040), weighted median estimation (OR = 1.078, 95% CI: 1.0365-1.1219, p = 1.831 × 10-4), weighted mode analysis (OR = 1.089, 95% CI: 1.0078-1.1771, p = 0.041) and simple mode analysis (OR = 1.093, 95% CI: 1.0112-1.1830, p = 0.034). Cochran's Q test showed no evidence of heterogeneity among the IV estimates derived from individual variants, and the MR-Egger regression analysis indicated that the presence of horizontal pleiotropy was unlikely to introduce bias into the results (intercept: -0.0044, p = 0.549).

Conclusions

Two-sample Mendelian randomization analysis effectively identified hip or knee osteoarthritis as a contributing risk factor for frailty.

Pathological progression of osteoarthritis: a perspective on subchondral bone

Osteoarthritis (OA) is a degenerative bone disease associated with aging. The rising global aging population has led to a surge in OA cases, thereby imposing a significant socioeconomic burden. Researchers have been keenly investigating the mechanisms underlying OA. Previous studies have suggested that the disease starts with synovial inflammation and hyperplasia, advancing toward cartilage degradation. Ultimately, subchondral-bone collapse, sclerosis, and osteophyte formation occur. This progression is deemed as "top to bottom." However, recent research is challenging this perspective by indicating that initial changes occur in subchondral bone, precipitating cartilage breakdown. In this review, we elucidate the epidemiology of OA and present an in-depth overview of the subchondral bone's physiological state, functions, and the varied pathological shifts during OA progression. We also introduce the role of multifunctional signal pathways (including osteoprotegerin (OPG)/receptor activator of nuclear factor-kappa B ligand (RANKL)/receptor activator of nuclear factor-kappa B (RANK), and chemokine (CXC motif) ligand 12 (CXCL12)/CXC motif chemokine receptor 4 (CXCR4)) in the pathology of subchondral bone and their role in the "bottom-up" progression of OA. Using vivid pattern maps and clinical images, this review highlights the crucial role of subchondral bone in driving OA progression, illuminating its interplay with the condition.

To Be Frail or Not to Be Frail: This Is the Question-A Critical Narrative Review of Frailty

Many factors have contributed to rendering frailty an emerging, relevant, and very popular concept. First, many pandemics that have affected humanity in history, including COVID-19, most recently, have had more severe effects on frail people compared to non-frail ones. Second, the increase in human life expectancy observed in many developed countries, including Italy has led to a rise in the percentage of the older population that is more likely to be frail, which is why frailty is much a more common concern among geriatricians compared to other the various health-care professionals. Third, the stratification of people according to the occurrence and the degree of frailty allows healthcare decision makers to adequately plan for the allocation of available human professional and economic resources. Since frailty is considered to be fully preventable, there are relevant consequences in terms of potential benefits both in terms of the clinical outcome and healthcare costs. Frailty is becoming a popular, pervasive, and almost omnipresent concept in many different contexts, including clinical medicine, physical health, lifestyle behavior, mental health, health policy, and socio-economic planning sciences. The emergence of the new "science of frailty" has been recently acknowledged. However, there is still debate on the exact definition of frailty, the pathogenic mechanisms involved, the most appropriate method to assess frailty, and consequently, who should be considered frail. This narrative review aims to analyze frailty from many different aspects and points of view, with a special focus on the proposed pathogenic mechanisms, the various factors that have been considered in the assessment of frailty, and the emerging role of biomarkers in the early recognition of frailty, particularly on the role of mitochondria. According to the extensive literature on this topic, it is clear that frailty is a very complex syndrome, involving many different domains and affecting multiple physiological systems. Therefore, its management should be directed towards a comprehensive and multifaceted holistic approach and a personalized intervention strategy to slow down its progression or even to completely reverse the course of this condition.

Cabozantinib prevents AGEs-induced degradation of type 2 collagen and aggrecan in human chondrocytes

Osteoarthritis (OA) is a joint degenerative disease commonly observed in the old population, lacks effective therapeutic methods, and markedly impacts the normal lives of patients. Degradation of extracellular matrix (ECM) is reported to participate in OA development, which is a potential target for treating OA. Cabozantinib is an inhibitor of tyrosine kinases and is recently claimed with suppressive properties against inflammation. Herein, the protective function of Cabozantinib on advanced glycation end products (AGEs)-induced damages to chondrocytes was tested. SW1353 chondrocytes were stimulated with 100 μg/ml AGEs with or without 10 and 20 μM Cabozantinib for 24 h. Signally increased reactive oxygen species (ROS) levels, declined reduced glutathione (GSH) levels, and elevated release of inflammatory cytokines were observed in AGEs-stimulated SW1353 chondrocytes, which were markedly reversed by Cabozantinib. Moreover, the notably reduced type II collagen and aggrecan levels, and increased matrix metalloproteinase-13 (MMP-13) and A Disintegrin and Metalloproteinase with Thrombospondin Motifs-5 (ADAMTS-5) levels in AGEs-stimulated SW1353 chondrocytes were largely rescued by Cabozantinib. The downregulated Sry-type high-mobility-group box 9 (SOX-9) observed in AGEs-stimulated SW1353 chondrocytes was abolished by Cabozantinib. Furthermore, the impact of Cabozantinib on type II collagen and aggrecan levels in AGEs-treated SW1353 chondrocytes was abrogated by silencing SOX-9. Collectively, Cabozantinib prevented AGEs-induced degradation of type 2 collagen and aggrecan in human chondrocytes by mediating SOX-9.

Harnessing the multifunctionality of lipid-based drug delivery systems for the local treatment of osteoarthritis

Osteoarthritis (OA) is a widespread joint condition affecting millions globally, presenting a growing socioeconomic burden thus making the development of more effective therapeutic strategies crucial. This review emphasizes recent advancements in lipid-based drug delivery systems (DDSs) for intra-articular administration of OA therapeutics, encompassing non-steroidal anti-inflammatory drugs, corticosteroids, small molecule disease-modifying OA drugs, and RNA therapeutics. Liposomes, lipid nanoparticles, lipidic mesophases, extracellular vesicles and composite systems exhibit enhanced stability, targeted delivery, and extended joint retention, which contribute to improved therapeutic outcomes and minimized systemic drug exposure. Although active targeting strategies hold promise, further research is needed to assess their targeting efficiency in physiologically relevant conditions. Simultaneously, multifunctional DDSs capable of delivering combinations of distinct therapeutic classes offer synergistic effects and superior OA treatment outcomes. The development of such long-acting systems that resist rapid clearance from the joint space is crucial, where particle size and targeting capabilities emerge as vital factors. Additionally, combining cartilage lubrication properties with sustained drug delivery has demonstrated potential in animal models, meriting further investigation in human clinical trials. This review highlights the crucial need for direct, head-to-head comparisons of novel DDSs with standard treatments, particularly within the same drug class. These comparisons are essential in accurately evaluating their effectiveness, safety, and clinical applicability, and are set to significantly shape the future of OA therapy.

Frailty predicts knee pain trajectory over 9 years: results from the Osteoarthritis Initiative

OBJECTIVE

Frailty is a multisystem syndrome and its relationship with symptomatic osteoarthritis has been reported. We aimed to identify trajectories of knee pain in a large prospective cohort and to describe the effect of frailty status at baseline on the pain trajectories over 9 years.

METHODS

We included 4419 participants (mean age 61.3 years, 58% female) from the Osteoarthritis Initiative cohort. Participants were classified as "no frailty," "pre-frailty," or "frailty" at baseline, based on 5 characteristics (ie, unintentional weight loss, exhaustion, weak energy, slow gait speed, and low physical activity). Knee pain was evaluated annually using the Western Ontario and McMaster Universities Osteoarthritis Index pain subscale (0-20) from baseline to 9 years.

RESULTS

Of the participants included, 38.4%, 55.4%, and 6.3% were classified as "no frailty," "pre-frailty," and "frailty," respectively. Five pain trajectories were identified: "No pain" (n = 1010, 22.8%), "Mild pain" (n = 1656, 37.3%), "Moderate pain" (n = 1149, 26.0%), "Severe pain" (n = 477, 10.9%), and "Very Severe pain" (n = 127, 3.0%). Compared to participants with no frailty, those with pre-frailty and frailty were more likely to have more severe pain trajectories (pre-frailty: odds ratios [ORs] 1.5 to 2.1; frailty: ORs 1.5 to 5.0), after adjusting for potential confounders. Further analyses indicated that the associations between frailty and pain were mainly driven by exhaustion, slow gait speed, and weak energy.

CONCLUSIONS

Approximately two-thirds of middle-aged and older adults were frail or pre-frail. The role of frailty in predicting pain trajectories suggests that frailty may be an important treatment target for knee pain.

Exploring the Nexus of lower extremity proprioception and postural stability in older adults with osteoporosis: a cross-sectional investigation

Background

Osteoporosis, characterized by reduced bone mass and micro-architectural deterioration, poses a significant public health concern due to increased fracture susceptibility. Beyond bone health, this cross-sectional study aimed to assess and compare lower extremity proprioception and postural stability in individuals with and without osteoporosis and to explore their correlation within the osteoporosis group.

Method

In this prospective cross-sectional study, 80 participants were divided into two groups: osteoporosis (n = 40) and control (n = 40). The demographic characteristics and clinical parameters of the participants were as follows: Age (years) - Osteoporosis group: 65.04 ± 4.33, Control group: 65.24 ± 4.63; Sex (%) - Osteoporosis group: Male 30%, Female 70%; Control group: Male 30%, Female 70%; Body mass index (kg/m2) - Osteoporosis group: 23.7 ± 3.2, Control group: 24.5 ± 4.6; T-score (Lumbar) - Osteoporosis group: -2.86 ± 1.23, Control group: 0.27 ± 0.58; T-score (hip) - Osteoporosis group: -2.28 ± 0.79, Control group: 0.68 ± 0.86. Joint Position Sense (JPS) at the hip, knee, and ankle was assessed using a digital inclinometer, and postural stability was measured using computerized force platforms.

Result

Osteoporosis participants exhibited higher errors in hip (5.63° vs. 2.36°), knee (4.86° vs. 1.98°), and ankle (4.46° vs. 2.02°) JPS compared to controls. Postural stability measures showed increased anterior-posterior sway (10.86 mm vs. 3.98 mm), medial-lateral sway (8.67 mm vs. 2.89 mm), and ellipse area (966.88 mm2 vs. 446.19 mm2) in osteoporosis participants. Furthermore, correlation analyses within the osteoporosis group unveiled significant positive associations between lower extremity proprioception and postural stability. Specifically, hip JPS exhibited a strong positive correlation with anterior-posterior sway (r = 0.493, p = 0.003), medial-lateral sway (r = 0.485, p = 0.003), and ellipse area (r = 0.496, p < 0.001). Knee JPS displayed a moderate positive correlation with anterior-posterior sway (r = 0.397, p = 0.012), medial-lateral sway (r = 0.337, p = 0.032), and ellipse area (r = 0.378, p < 0.001). Similarly, ankle JPS showed a moderate positive correlation with anterior-posterior sway (r = 0.373, p = 0.023), medial-lateral sway (r = 0.308, p = 0.045), and ellipse area (r = 0.368, p = 0.021).

Conclusion

These findings underscore the interplay between proprioceptive deficits, compromised postural stability, and osteoporosis, emphasizing the need for targeted interventions to improve fall prevention strategies and enhance the quality of life for individuals with osteoporosis.

Knee osteoarthritis with a high grade of Kellgren-Lawrence score is associated with a worse frailty status, KNHANES 2010-2013

Frailty as a syndrome of physical decline in late life is associated with adverse health outcomes. Knee osteoarthritis (KOA) could contribute to frailty conditions. The objective of this study was to evaluate the impact of KOA on frailty risk in a Korean National Health and Nutrition Examination Survey (KNHANES) cohort. In this study (N, total = 11,910, age; 64.10 years old [63.94-64.27; mean 95% CI], sex (female, %); 6,752 (56.69)), KOA patients were defined as those with knee joint pain and grade 2 Kellgren-Lawrence (K-L) or more on plain radiographic images who were 40 years old or older in Korean population data of KNHANES. The frailty index was calculated using 46 items related to co-morbidities and laboratory parameters. The impact of KOA on frailty risk was evaluated with logistic regression analyses. The prevalence of KOA patients was 35.6% [95% CI 34.7-36.46]. In polytomous logistic regression, the relative risk ratio (RRR) of KOA was significantly increased in the pre-frail group (2.76, 95% CI 2.30-3.31) and the frail group (7.28, 95% CI 5.90-8.98). RRR of frailty was significantly increased in patients with K-L grade 3 (1.36, 95% CI 1.13-1.63) and K-L grade 4 (2.19, 95% CI 1.72-2.79). Older age, higher BMI, smoking status, alcohol intake, low-income status, higher WBC count, higher platelet count, higher serum creatinine level and low estimated GFR were significantly associated with increased frailty risk. High hemoglobin and regular walking habits were associated with decreased frailty risk in KOA patients. In this large observation population- based survey cohort, KOA is linked to an increased risk of frailty syndrome. We found a significant connection between KOA and frailty syndrome. These results show that we need to think about the overall health of people with KOA and give them special care to prevent frailty syndrome.

An alternative treatment option in older adults with knee osteoarthritis : Genicular nerve pulsed radiofrequency

Osteoarthritis (OA), including knee OA (KOA), is an important cause of morbidity and disability in older adults. Pain management plays a major role in the treatment of KOA for pain relief and knee function improvement. Ultrasound-guided genicular nerve pulsed radiofrequency therapy is an effective, safe, nonradiative, and easily applicable treatment modality in older adults with KOA. It has a positive effect on geriatric syndromes, especially polypharmacy.

Association of smoking with cartilage loss of knee osteoarthritis: data from two longitudinal cohorts

BACKGROUND

Previous studies have been inconsistent concerning the association between smoking and risk of osteoarthritis (OA). This study aimed to explore the associations of smoking status and change in cartilage volume of OA in two longitudinal cohorts.

METHODS

Subjects from the Osteoarthritis Initiative cohort (OAI, n = 593) and the Tasmanian Older Adult Cohort (TASOAC, n = 394) were included in this study. For both cohorts, participants were classified into three groups based on their smoking status, namely 'never', 'former', and 'current' smokers. The outcome measures were the annual rate of change of tibiofemoral cartilage volume over 2 years in OAI and of tibial cartilage volume over 2.6 years in TASOAC. Potential confounders were balanced using the inverse probability of treatment weighting (IPTW) method.

RESULTS

Overall, 42.3% and 37.4% of participants were former smokers, and 5.7% and 9.3% were current smokers in the OAI and TASOAC cohorts, respectively. Compared to never smokers, neither former nor current smoking was associated with risk of the annual rate of change of tibiofemoral cartilage volume in OAI (former smoker: β=-0.068%/year, 95% confidence interval [CI] -0.824 to 0.688, p = 0.860; current smoker: β=-0.222%/year, 95% CI -0.565 to 0.120, p = 0.204) and tibial cartilage volume in TASOAC (former smoker: β = 0.001%/year, 95% CI -0.986 to 0.989, p = 0.998; current smoker: β=-0.839%/year, 95% CI -2.520 to 0.844, p = 0.329).

CONCLUSIONS

Our findings from two independent cohorts consistently showed that smoking was not associated with knee cartilage loss in older adults.

Supraspinal neuroinflammation and anxio-depressive-like behaviors in young- and older- adult mice with osteoarthritis pain: the effect of morphine

RATIONALE

Asteoarthritis (OA) is a leading cause of chronic pain in the elderly population and is often associated with emotional comorbidities such as anxiety and depression. Despite age is a risk factor for both OA and mood disorders, preclinical studies are mainly conducted in young adult animals.

OBJECTIVES

Here, using young adult (11-week-old) and older adult (20-month-old) mice, we evaluate in a monosodium-iodoacetate-(MIA)-induced OA model the development of anxio-depressive-like behaviors and whether brain neuroinflammation may underlie the observed changes. We also test whether an effective pain treatment may prevent behavioral and biochemical alterations.

METHODS

Mechanical allodynia was monitored throughout the experimental protocol, while at the end of protocol (14 days), anxio-depressive-like behaviors and cognitive dysfunction were assessed. Neuroinflammatory condition was evaluated in prefrontal cortex, hippocampus and hypothalamus. Serum IFNγ levels were also measured. Moreover, we test the efficacy of a 1-week treatment with morphine (2.5 mg/kg) on pain, mood alterations and neuroinflammation.

RESULTS

We observed that young adult and older adult controls (CTRs) mice had comparable allodynic thresholds and developed similar allodynia after MIA injection. Older adult CTRs were characterized by altered behavior in the tests used to assess the presence of depression and cognitive impairment and by elevated neuroinflammatory markers in brain areas compared to younger ones. The presence of pain induced depressive-like behavior and neuroinflammation in adult young mice, anxiety-like behavior in both age groups and worsened neuroinflammation in older adult mice. Morphine treatment counteracted pain, anxio-depressive behaviors and neuroinflammatory activation in both young adult and older adult mice.

CONCLUSIONS

Here, we demonstrated that the presence of chronic pain in young adult mice induces mood alterations and supraspinal biochemical changes and aggravates the alterations already evident in older adult animals. A treatment with morphine, counteracting the pain, prevents the development of anxio-depressive disorders and reduces neuroinflammation.

Cardiometabolic Disorders Are Important Correlates of Vulnerability in Hospitalized Older Adults

With an increasingly aging population worldwide, the concept of multimorbidity has attracted growing interest over recent years, especially in terms of frailty, which leads to progressive multisystem decline and increased adverse clinical outcomes. The relative contribution of multiple disorders to overall frailty index in older populations has not been established so far. This study aimed to assess the association between the vulnerable elders survey-13 (VES-13) score, which is acknowledged to be one of the most widely used measures of frailty, and the most common accompanying diseases amongst hospitalized adults aged 60 years old and more. A total of 2860 participants with an average age of 83 years were included in this study. Multiple logistic regression with adjustment for age and nutritional status was used to assess the independent impact of every particular disease on vulnerability. Diabetes mellitus type 2, coronary artery disease, atrial fibrillation, heart failure, chronic kidney disease, osteoarthritis, fractures, eyes disorders, depression, dementia, pressure ulcers, and urinary incontinence were associated with higher scores of VES-13. Hospital admission of older subjects with those conditions should primarily draw attention to the risk of functional decline, especially while qualifying older patients for further treatment in surgery and oncology. At the same time, lipid disorders, gastrointestinal diseases, higher body mass index, and albumins level were related to a lower risk of being vulnerable, which may be attributed to a younger age and better nutritional status of those patients.

The Potential Role of Spa Therapy in Managing Frailty in Rheumatic Patients: A Scoping Review

Frailty is not limited to the elderly, as patients with rheumatic diseases can also experience this condition. The present scoping review aimed to investigate the possibility of using the health resort setting as an alternative location for managing rheumatic patients with frailty. The research resulted in finding several in vitro, in vivo, and clinical studies, resulting in evidence supporting the effectiveness of spa treatments in reducing pain, improving function, and managing comorbidity in rheumatic diseases. Additionally, spa treatments were demonstrated to modulate the MAPK/ERK pathway and the NF-kB pathway's activation and to reduce proinflammatory molecules' secretion in rheumatic diseases, thus suggesting their potential effective role in the regulation of inflammaging in frailty. Moreover, the health resort setting may offer potential resources to reduce risk factors, such as drug consumption, inactivity, and disease severity, and may serve as a setting for developing prevention protocols for frailty. Future research should explore innovative approaches, such as exercise training and early diagnostics, for the overall management of frailty in rheumatic patients in the spa setting.

In major joint diseases the human synovium retains its potential to form repair cartilage

The inner surface layer of human joints, the synovium, is a source of stem cells for the repair of articular cartilage defects. We investigated the potential of the normal human synovium to form novel cartilage and compared its chondrogenic capacity with that of two patient groups suffering from major joint diseases: young adults with femoro-acetabular impingement syndromes of the hip (FAI), and elderly individuals with osteoarthritic degeneration of the knee (OA). Synovial membrane explants of these three patient groups were induced in vitro to undergo chondrogenesis by growth factors: bone morphogenetic protein-2 (BMP-2) alone, transforming growth factor-β1 (TGF-β1) alone, or a combination of these two. Quantitative evaluations of the newly formed cartilages were performed respecting their gene activities, as well as the histochemical, immunhistochemical, morphological and histomorphometrical characteristics. Formation of adult articular-like cartilage was induced by the BMP-2/TGF-β1 combination within all three groups, and was confirmed by adequate gene-expression levels of the anabolic chondrogenic markers; the levels of the catabolic markers remained low. Our data reveal that the chondrogenic potential of the normal human synovium remains uncompromised, both in FAI and OA. The potential of synovium-based clinical repair of joint cartilage may thus not be impaired by age-related joint pathologies.

Exploring disease interrelationships in older inpatients: a single-centre, retrospective study

Background

Comorbidity is a common phenomenon in the older population; it causes a heavy burden on societies and individuals. However, the relevant evidence, especially in the southwestern region of China, is insufficient.

Objectives

We aimed to examine current comorbidity characteristics as well as correlations among diseases in individuals aged >60 years.

Design

Retrospective study.

Methods

We included records of 2,995 inpatients treated at the Gerontological Department of Sichuan Geriatric Hospital from January 2018 to February 2022. The patients were divided into groups according to sex and age. Diseases were categorised based on the International Classification of Diseases and their Chinese names. We calculated the age-adjusted Charlson Comorbidity Index (ACCI), categorised diseases using the China Health and Retirement Longitudinal Study questionnaire, and visualised comorbidity using web graphs and the Apriori algorithm.

Results

The ACCI was generally high, and it increased with age. There were significant differences in the frequency of all diseases across age groups, especially in individuals aged ≥90 years. The most common comorbid diseases were liver diseases, stomach or other digestive diseases, and hypertension. Strong correlations between the most common digestive diseases and hypertension were observed.

Conclusion

Our findings provide insights into the current situation regarding comorbidity and the correlations among diseases in the older population. We expect our findings to inform future research directions as well as policies regarding general clinical practice and public health, especially for medical consortiums.

Analysis of the regulatory role of miR-34a-5p/PLCD3 in the progression of osteoarthritis

Osteoarthritis is a heterogeneous disease with a complex etiology. However, there is no effective treatment strategy at present. The purpose of this study was to explore the miRNA‒mRNA regulatory network and molecular mechanism that regulate the progression of osteoarthritis. In this article, we downloaded datasets (GSE55457, GSE82107, GSE143514 and GSE55235) from Gene Expression Omnibus (GEO) to screen differentially expressed mRNAs in osteoarthritis. Then, through weighted gene coexpression network (WGCNA), functional enrichment, protein‒protein interaction (PPI) network, miRNA‒mRNA coexpression network, ROC curve, and immune infiltration analyses and qPCR, the mRNA PLCD3, which was highly expressed in osteoarthritis and had clinical predictive value, was screened. We found that PLCD3 directly targets miR-34a-5p through DIANA and dual-luciferase experiments. The expression levels of PLCD3 and miR-34a-5p were negatively correlated. In addition, CCK-8 and wound healing assays showed that the miR-34a-5p mimic inhibited hFLS-OA cell proliferation and promoted hFLS-OA cell migration. PLCD3 overexpression showed the opposite trend. Western blotting further found that overexpression of miR-34a-5p reduced the protein expression levels of p-PI3K and p-AKT, while overexpression of PLCD3 showed the opposite trend. In addition, combined with the effect of the PI3K/AKT pathway inhibitor BIO (IC50 = 5.95 μM), the results showed that overexpression of miR-34a-5p increased the inhibitory effects of BIO on p-PI3K and p-AKT protein expression, while overexpression of PLCD3 significantly reversed these inhibitory effects. Overall, the miR-34a-5p/PLCD3 axis may mediate the PI3K/AKT pathway in regulating cartilage homeostasis in synovial osteoarthritis. These data indicate that miR-34a-5p/PLCD3 may be a new prognostic factor in the pathology of synovial osteoarthritis.

The Effects of Osteoarthritis on Depressive Symptomatology Among Older U.S. Military Veterans

Osteoarthritis (OA) is a leading cause of disability among older adults. By 2050, approximately 60 million will suffer from arthritis adding up to a total societal cost of $65 billion. Chronic illnesses resulting in pain, and functional decline have been associated with depression in previous studies.A causal model was developed and tested using structural equation modeling that examined depression scores of 503 older (age 50-85), male Veterans with moderate to severe symptomatic OA of the knee\hip.The results of the structural equation modeling produced a final model of depressive symptomatology that fit the data well (Chi square = 12.23, DF = 11, p = .346; TLI = .99; CFI = 1.00; RMSEA = .02).The findings indicate the central role that OA severity (pain, stiffness, and functional difficulties) plays in the mental health of older Veterans in terms of the level of reported depressive symptoms.

Osteoarthritis: pathogenic signaling pathways and therapeutic targets

Osteoarthritis (OA) is a chronic degenerative joint disorder that leads to disability and affects more than 500 million population worldwide. OA was believed to be caused by the wearing and tearing of articular cartilage, but it is now more commonly referred to as a chronic whole-joint disorder that is initiated with biochemical and cellular alterations in the synovial joint tissues, which leads to the histological and structural changes of the joint and ends up with the whole tissue dysfunction. Currently, there is no cure for OA, partly due to a lack of comprehensive understanding of the pathological mechanism of the initiation and progression of the disease. Therefore, a better understanding of pathological signaling pathways and key molecules involved in OA pathogenesis is crucial for therapeutic target design and drug development. In this review, we first summarize the epidemiology of OA, including its prevalence, incidence and burdens, and OA risk factors. We then focus on the roles and regulation of the pathological signaling pathways, such as Wnt/β-catenin, NF-κB, focal adhesion, HIFs, TGFβ/ΒΜP and FGF signaling pathways, and key regulators AMPK, mTOR, and RUNX2 in the onset and development of OA. In addition, the roles of factors associated with OA, including MMPs, ADAMTS/ADAMs, and PRG4, are discussed in detail. Finally, we provide updates on the current clinical therapies and clinical trials of biological treatments and drugs for OA. Research advances in basic knowledge of articular cartilage biology and OA pathogenesis will have a significant impact and translational value in developing OA therapeutic strategies.

Anserine bursa palpation tenderness is a risk factor for knee osteoarthritis progression and arthroplasty: data from the Osteoarthritis Initiative

OBJECTIVE

Anserine bursa pain (ABP) is defined as the presence of palpation tenderness medially below the joint line, which is 2 cm from the tibial tuberosity. This study aimed to determine a link between ABP and three knee outcomes: frequent pain, joint space narrowing (JSN) progression, and total knee arthroplasty (TKA).

METHODS

Participants from the Osteoarthritis Initiative cohort were included in this study. Frequent ABP was defined as presenting thrice at four-time points. The Chi-square test and binary logistic regression analyses examined the associations between ABP and the three knee outcomes. Furthermore, Cox Proportional Hazards Model explored the association between ABP and TKA.

RESULTS

Baseline ABP was linked to a higher risk of frequent pain (odds ratio (OR): 2.28, 95% confidence interval (CI): 1.76-2.97, P < 0 .001) and TKA (OR: 1.54, 95% CI 1.01-2.36, P = 0 .044) after adjusting for gender, baseline age, body mass index (BMI), and Kellgren-Lawrence (KL) grade. In the frequent ABP group from baseline to the 4-year follow-up (≥ 3 of four-time points), frequent pain (OR: 3.14, 95% CI: 2.34-4.22, P < 0 .001) and TKA (OR: 1.79, 95% CI: 1.11-2.90, P = 0 .017) had a high association with ABP after adjusting for gender, baseline age, BMI, and KL grade.

CONCLUSION

This study highlights the association between ABP and knee outcomes; therefore, clinicians should pay closer attention during the physical examination, especially in middle-aged and older female patients. Moreover, understanding ABP cause aids in better diagnosis and treatment. Key Points • This is the first study to identify an association between anserine bursa palpation tenderness and symptomatic knee osteoarthritis. • As opposed to most studies, which focus on intra-articular symptoms and signs, this study focused on extra-articular symptoms and signs. • Clinically, anserine bursa palpation tenderness can be utilized to determine patients at risk for the progression of knee osteoarthritis, thereby aiding in providing early therapeutic intervention.

Osteoarthritis or arthritis? Toward understanding of primary Sjögren's syndrome patients with arthralgia

OBJECTIVE

To identify primary Sjögren's syndrome (pSS) patients with arthralgia at risk for osteoarthritis (OA) or arthritis.

METHODS

This study included 368 pSS patients admitted to a mono-centric from March 2010 to December 2020. Patients were divided into groups according to whether complicated with OA or arthritis. Data were analyzed to determine the differences in demographical characteristics, symptoms, and laboratory examination.

RESULTS

The involvement of the OA joints was predominately knee and spine sites (including cervical and lumbar spine degeneration). When diagnosing arthritis, it was mainly peripheral symmetric polyarthritis, the most affected sites were the interphalangeal and metacarpophalangeal joints. There were significant differences in age, disease duration, uric acid (UA), and total cholesterol (TC) between pSS-OA and pSS-nOA patients (P < 0.050). Logistic regression analysis showed that age (OR = 1.965; P = 0.009) and joint pain (OR = 3.382; P < 0.001) were dangerous factors associated with OA. Interestingly, although the level of UA, TC, and triglycerides (TG) was shown to be positive with OA, there was no statistical significance after the OR was computed in the four-cell table. In pSS-arthritis, EULAR Sjögren's syndrome disease activity index (ESSDAI) (P = 0.011), the frequency of joint pain (P < 0.001), and muscular involvement (P = 0.037) were higher than non-arthritis group. In pSS patients only presenting with joint pain, arthritis patients had higher ESSDAI and system involvements, but lower UA and TG levels compared with OA group (P < 0.050).

CONCLUSION

In pSS patients with arthralgia, OA accounted for the majority. pSS patients with advanced age and more pronounced metabolic characteristics, such as elevated blood lipids and uric acid, was a key factor in groups at risk for OA. However, arthritis patients had higher rates of dry mouth and eye, higher disease activity, antibodies positive, and more organs damage. In the future, it may be necessary to be more cautious in the diagnosis of joint manifestations in pSS patients in order to make the appropriate treatments.

Association between Elevated Magnesium Intake and Reduced Risk of Recurrent Falls and Frailty in Osteoarthritis: Data from the Osteoarthritis Initiative

OBJECTIVES

The objective of this 8-year follow-up study was to investigate the relationship between magnesium intake and frailty, as well as recurrent falls, in individuals diagnosed with Osteoarthritis (OA) or those at a heightened risk for developing the condition.

METHODS

This study utilized data from the Osteoarthritis Initiative (OAI) database and conducted a prospective cohort study with a 8-year follow-up period. Total magnesium intake from both food sources and supplements was assessed using a food frequency questionnaire (FFQ), while frailty and recurrent falls were evaluated through established criteria and self-report, respectively. To account for potential confounding factors, various covariates were considered, and statistical analyses, including generalized additive mixed models (GAMMs), were employed to examine the associations.

RESULTS

Among the 4,667 participants with OA, those with lower total magnesium intake were characterized by younger age, a higher proportion of African American individuals, higher body mass index (BMI), and lower dietary fiber intake (P<0.001). Notably, this group exhibited higher odds of experiencing recurrent falls and frailty (P = 0.034 and 0.006, respectively). Controlling for various factors, the GAMMs consistently revealed negative correlations between magnesium intake and the likelihood of frailty and recurrent falls, with each 1 mg/1000 kcal increase in magnesium intake associated with a 0.5% reduced frailty risk (p < 0.001) and a 0.2% decreased risk of recurrent falls (p = 0.001). Subgroup analyses suggested that increased total magnesium intake from both food sources and supplements may exert a more pronounced preventive effect on recurrent falls and frailty in men, older adults, individuals with normal BMI, and those with higher dietary fiber intake.

CONCLUSIONS

Elevated total magnesium intake from both food sources and supplements was found to be associated with a decreased risk of recurrent falls and frailty in individuals diagnosed with OA or those at risk of developing the condition. These findings imply that increased total magnesium intake might be beneficial in managing the risk of these outcomes, particularly within specific subgroups, including men, older adults, those with a normal BMI, and those with higher dietary fiber intake.

Medicinal plants and their secondary metabolites in alleviating knee osteoarthritis: A systematic review

BACKGROUND

With the increasing ages of the general population, the incidence of knee osteoarthritis (KOA) is also rising, and KOA has become a major health problem worldwide. Recently, medicinal plants and their secondary metabolites have gained interest due to their activity in treating KOA. In this paper, a comprehensive systematic review of the literature was performed concerning the effects of medicinal plant extracts and natural compounds against KOA in recent years. The related molecular pathways of natural compounds against KOA were summarized, and the possible crosstalk among components in chondrocytes was discussed to propose possible solutions for the current situation of treating KOA.

PURPOSE

This review focused on the molecular mechanisms by which medicinal plants and their secondary metabolites act against KOA.

METHODS

Literature searches were performed in the PUBMED, Embase, Science Direct, and Web of Science databases for a 10-year period from 2011 to 2022 with the search terms "medicinal plants," "bioactive compounds," "natural products," "phytochemical," "knee osteoarthritis," "knee joint osteoarthritis," "knee osteoarthritis," "osteoarthritis of the knee," and "osteoarthritis of knee joint."

RESULTS

According to the results, substantial plant extracts and secondary metabolites show a positive effect in fighting KOA. Plant extracts and their secondary metabolites can affect the diagnostic and prognostic biomarkers of KOA. Natural products inhibit the expression of MMP1, MMP3, MMP19, syndecan IV, ADAMTS-4, ADAMTS-5, iNOS, COX-2, collagenases, IL-6, IL-1β, and TNF-α in vitro and in vivo and . Cytokines also upregulate the expression of collagen II and aggrecan. The main signaling pathways affected by the extracts and isolated compounds include AMPK, SIRT, NLRP3, MAPKs, PI3K/AKT, mTOR, NF-κB, WNT/β-catenin, JAK/STAT3, and NRF2, as well as the cell death modes apoptosis, autophagy, pyroptosis, and ferroptosis.

CONCLUSION

The role of secondary metabolites in different signaling pathways supplies a better understanding of their potential to develop further curative options for KOA.

Prevalence and Characteristics of Frailty at 6 months FollOwing Total Hip and Knee Arthroplasty in Patients With End-Stage OA

Introduction

Lower-limb osteoarthritis (OA) in the elderly can be a risk factor for frailty, which is the preliminary of disability, but it may be reversible with appropriate interventions. We aimed to use the Kihon Check List (KCL) to assess multiple domains of frailty and to identify the characteristics of frailty in patients with hip or knee OA following total joint arthroplasty.

Materials and Methods

This study included 136 ≥ 65-year-old patients (mean age: 73.0 years) who underwent total arthroplasty with end-stage hip and knee OA. We assessed frailty status, instrumental activities of daily living (IADL), and health-related quality of life (HRQoL) according to the KCL, functional ambulatory index (FAI) and EuroQol-5 Dimension (EQ5D), respectively, as well as the extent of pain preoperatively and at postoperative 6 months.

Results

Using KCL, seventy-eight (57.4%) patients were frail preoperatively, but the prevalence significantly decreased to 52 patients (38.2%) at postoperative 6 months. Total arthroplasty intervention provided significant improvements in the total KCL scores, including the physical domain (P < .01), pain (P < .01), FAI scores (P < .01), and EQ5D (P < .01), but not the social domain. Multivariate logistic regression analysis identified age at surgery (OR: .93, 95% CI: .86-.99) and preoperative FAI score (OR: 1.10, 95% CI: 1.03-1.19) as independent predictors of postoperative frailty.

Conclusions

Total arthroplasty procedures on patients with hip and knee OA reduced their KCL score, but social aspects were less improved than physical aspects in the shortterm. Older age and preoperative lower IADL score can be useful for accurately estimating less improvement of frailty in the early postoperative phase. Our results suggest that long term follow-up of OA is needed to provide comprehensive interventions, including in social aspects, especially for patients with lower activity.

The Level of Histone Deacetylase 4 is Associated with Aging Cartilage Degeneration and Chondrocyte Hypertrophy

Purpose

To determine the role of histone deacetylase 4 (HDAC4)-controlled chondrocyte hypertrophy in the onset and development of age-related osteoarthritis (OA).

Methods

Morphological analysis of human knee cartilages was performed to observe structural changes during cartilage degeneration. HDAC4 expression was deleted in adult aggrecan (Acan)-CreERT2; HDAC4fl/fl transgenic mice. The onset and development of age-related OA were investigated in transgenic and control mice using hematoxylin and eosin (H&E) and Safranin O staining. Furthermore, the progression of ACLT-induced OA following adenovirus-mediated HDAC4 overexpression was explored in rats. The expression levels of genes related to hypertrophy, cartilage matrix and its digestion, and chondrocyte proliferation were investigated using qPCR. Immunohistochemistry (IHC) was used to explore the mechanisms underlying HDAC4-controlled age-related changes in OA progression.

Results

In human cartilage, we performed morphological analysis and IHC, the results showed that hypertrophy-related structural changes are related to HDAC4 expression. Age-related OA was detected early (OARSI scores 2.7 at 8-month-old) following HDAC4 deletion in 2-month-old mice. Furthermore, qPCR and IHC results showed changes in hypertrophy-related genes Col10a1, Runx2 and Sox9 in chondrocytes, particularly in the expression of Runt-related transcription factor 2 (Runx2, 13.29±0.99 fold). The expression of the main cartilage matrix-related genes Col2a1 and Acan decreased, that of cartilage matrix digestion-related gene MMP-13 increased, while that of chondrocyte proliferation-related genes PTHrP, Ihh and Gli1 changed. In contrast, rat cartilage’s qPCR and IHC results showed opposite outcomes after HDAC4 overexpression.

Conclusion

Based on the results above, we concluded that HDAC4 expression regulates the onset and development of age-related OA by controlling chondrocyte hypertrophy. These results may help in the development of early diagnosis and treatment of age-related OA.

A Comparative study of osteoarthritic knee patients between urban and rural areas in knee severity and quality of life

Osteoarthritis Knee (OA) is the leading cause of pain and disability. This may affect the patient’s quality of life (QoL) and lead to the onset of mental disorders. The aim of this study was 1) To find the correlation between the severity of OA, depression, and QoL. 2) To compare the severity of OA knee and QoL between urban and rural areas. 199 patients were diagnosed with OA. All patients had self-assessment with questionnaires in terms of 1) demographic data, 2) the knee severity by using Oxford Knee Score, 3) Depression screening by using Patient Health Questionnaire, and 4) World Health Organization Quality of Life Brief-Thai. The results revealed that OA knee patients had excellent (no abnormal symptoms) and good (mild symptoms) levels of severity were 34.2% and 32.2%, respectively. They also had a good level of QoL. The correlation between residential area and other variables were age group (p < 0.01), severity of osteoarthritis (p < 0.01), and depression (p < 0.05). The severity of OA knee and QoL in the mental health aspect was a significant difference in patients in each age group. (p < 0.01 and p < 0.05, respectively). Depression and QoL were not correlated. The conclusion was patients had less severity of osteoarthritis, good QoL, and no anxiety or depression. Residential areas had no impact on QoL but healthcare providers should explain the treatment plan. The next study should focus on the long term of the patient’s QoL.

Chronic Pain in the Elderly: Mechanisms and Perspectives

Chronic pain affects a large part of the population causing functional disability, being often associated with coexisting psychological disorders, such as depression and anxiety, besides cognitive deficits, and sleep disturbance. The world elderly population has been growing over the last decades and the negative consequences of chronic pain for these individuals represent a current clinical challenge. The main painful complaints in the elderly are related to neurodegenerative and musculoskeletal conditions, peripheral vascular diseases, arthritis, and osteoarthritis, contributing toward poorly life quality, social isolation, impaired physical activity, and dependence to carry out daily activities. Organ dysfunction and other existing diseases can significantly affect the perception and responses to chronic pain in this group. It has been proposed that elderly people have an altered pain experience, with changes in pain processing mechanisms, which might be associated with the degeneration of circuits that modulate the descending inhibitory pathways of pain. Aging has also been linked to an increase in the pain threshold, a decline of painful sensations, and a decrease in pain tolerance. Still, elderly patients with chronic pain show an increased risk for dementia and cognitive impairment. The present review article is aimed to provide the state-of-art of pre-clinical and clinical research about chronic pain in elderly, emphasizing the altered mechanisms, comorbidities, challenges, and potential therapeutic alternatives.

Predicting Venous Thrombosis in Osteoarthritis Using a Machine Learning Algorithm: A Population-Based Cohort Study

Osteoarthritis (OA) is the most common joint disease associated with pain and disability. OA patients are at a high risk for venous thrombosis (VTE). Here, we developed an interpretable machine learning (ML)-based model to predict VTE risk in patients with OA. To establish a prediction model, we used six ML algorithms, of which 35 variables were employed. Recursive feature elimination (RFE) was used to screen the most related clinical variables associated with VTE. SHapley additive exPlanations (SHAP) were applied to interpret the ML mode and determine the importance of the selected features. Overall, 3169 patients with OA (average age: 66.52 ± 7.28 years) were recruited from Xi’an Honghui Hospital. Of these, 352 and 2817 patients were diagnosed with and without VTE, respectively. The XGBoost algorithm showed the best performance. According to the RFE algorithms, 15 variables were retained for further modeling with the XGBoost algorithm. The top three predictors were Kellgren–Lawrence grade, age, and hypertension. Our study showed that the XGBoost model with 15 variables has a high potential to predict VTE risk in patients with OA.

Physical resilience as a moderator of the relationship between frailty and disability in older adults with osteoarthritis

AIMS

Frailty is a leading cause of deteriorating physical function of older adults with osteoarthritis. This study examined a model of frailty with the goals of (1) exploring the direct effect of osteoarthritic symptoms on disability and the mediating effect of frailty on disability and (2) determining whether both effects are moderated by physical resilience.

DESIGN

A cross-sectional descriptive study.

METHODS

Data collection was conducted among patients 65-92 years of age (N = 235) who visited primary medical centres for the management of chronic arthritic pain between July and December 2019. Participants completed a questionnaire measuring osteoarthritic symptoms, frailty, physical resilience, and disability. SPSS 25.0 was used to analyse the conditional process model. This study was reported following the STROBE guidelines.

RESULTS

Frailty was shown to be a mediator between osteoarthritic symptoms and disability. Furthermore, physical resilience played a role as a moderator in both the direct and indirect pathways of this mediating relationship.

CONCLUSION

The findings emphasize the detrimental effects of osteoarthritic symptoms on disability through frailty, and the moderated mediation results suggest that these effects were conditional on physical resilience, which is a modifiable internal resource of individuals. When planning nursing interventions for older adults with osteoarthritis, nurses need to consider physical resilience as a moderator to prevent frailty and disability.

Cholesterol metabolism related genes in osteoarthritis

Cholesterol homeostasis plays a significant role in skeletal development and the dysregulation of cholesterol-related mechanism has been shown to be involved in the development of cartilage diseases including osteoarthritis (OA). Epidemiological studies have shown an association between elevated serum cholesterol levels and OA. Furthermore, abnormal lipid accumulation in chondrocytes as a result of abnormal regulation of cholesterol homeostasis has been demonstrated to be involved in the development of OA. Although, many in vivo and in vitro studies support the connection between cholesterol and cartilage degradation, the mechanisms underlying the complex interactions between lipid metabolism, especially HDL cholesterol metabolism, and OA remain unclear. The current review aims to address this problem and focuses on key molecular players of the HDL metabolism pathway and their role in ΟΑ pathogenesis. Understanding the complexity of biological processes implicated in OA pathogenesis, such as cholesterol metabolism, may lead to new targets for drug therapy of OA patients.

Health-related quality of life in osteoarthritis patients: a systematic review and meta-analysis

The aim of this meta-analysis was to compare health-related quality of life (HRQoL) of Osteoarthritis (OA) patients and controls. A systematic literature search was performed on PubMed, Web of Science and EMBASE from database inception to 7 January 2020. Random effect model was performed to summarize the scores of each domain and the forest plot was used to compare the scores of OA patients with healthy controls. Subgroup analyses were conducted to explore the source of heterogeneity. Statistical analyses were executed using Review Manager (version 5.1). In total, six studies were included in this study, including 7094 patients with OA and 12 100 healthy controls, which were all reliable to summarize the scores of the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36). Meta-analyses found that pooled mean HRQoL score for the SF-36 each domain (physical function, physical role function, body pain, general health, vitality, social function, emotional role function, mental health) was lower in patients with OA than in healthy controls, especially the score in the dimension of physical role function. OA have a substantial impact HRQoL. HRQoL is a significant component of measuring overall health, which contributes to formulate successful self-disease management plan, patient-centered care, and develop effective interventions target confidence.

Assessing Prevalence and Factors Related to Frailty in Community-Dwelling Older Adults: A Multinomial Logistic Analysis

Frailty is an age-related clinical condition that typically involves a deterioration in the physiological capacity of various organ systems and heightens the patient’s susceptibility to stressors. For this reason, one of the main research goals currently being addressed is that of characterising the impact of frailty in different settings. The main aim of this study is to determine the prevalence of Fried’s frailty phenotype among community-dwelling older people and to analyse the factors associated with frailty. In this research study, 582 persons aged 65 years or more participated in this cross-sectional study that was conducted at primary healthcare centres in Málaga, Spain. Sociodemographic, clinical, functional and comprehensive drug therapy data were compiled. The relationship between the independent variables and the different states of frailty was analysed by using a multinomial logistic regression model. Frailty was present in 24.1% of the study sample (95% CI = 20.7–27.6) of whom 54.3% were found to be pre-frail and 21.6% were non-frail. The study variable most strongly associated with frailty was the female gender (OR = 20.54, 95% CI = 9.10–46.3). Other factors found to be associated with the state of frailty included age, dependence for the instrumental activities of daily living (IADL), polymedication, osteoarticular pathology and psychopathology. This study confirms the high prevalence of frailty among community-dwelling older people. Frailty may be associated with many factors. Some of these associated factors may be preventable or modifiable and, thus, provide clinically relevant targets for intervention. This is particularly the case for depressive symptoms, the clinical control of osteoarthritis and the use of polypharmacy.

Gender and Sex Are Key Determinants in Osteoarthritis Not Only Confounding Variables. A Systematic Review of Clinical Data

Many risk factors for osteoarthritis (OA) have been noted, while gender/sex differences have been understated. The work aimed to systematically review literature investigating as primary aim the relationship between gender/sex related discriminants and OA. The search was performed in PubMed, Science Direct and Web of Knowledge in the last 10 years. Inclusion criteria were limited to clinical studies of patients affected by OA in any joints, analyzing as primary aim gender/sex differences. Exclusion criteria were review articles, in vitro, in vivo and ex vivo studies, case series studies and papers in which gender/sex differences were adjusted as confounding variable. Of the 120 records screened, 42 studies were included. Different clinical outcomes were analyzed: morphometric differences, followed by kinematics, pain, functional outcomes after arthroplasty and health care needs of patients. Women appear to use more health care, have higher OA prevalence, clinical pain and inflammation, decreased cartilage volume, physical difficulty, and smaller joint parameters and dimensions, as compared to men. No in-depth studies or mechanistic studies analyzing biomarker differential expressions, molecular pathways and omic profiles were found that might drive preclinical and clinical research towards sex-/gender-oriented protocols.

Osteoking Decelerates Cartilage Degeneration in DMM-Induced Osteoarthritic Mice Model Through TGF-β/smad-dependent Manner

Osteoarthritis (OA) is a common disease characterized by cartilage degeneration. In recent years much attention has been paid to Traditional Chinese Medicine (TCM) since its treatments have shown efficacy for ameliorating cartilage degradation with mild side effects. Osteoking is a TCM prescription that has long been used in OA treatment. However, the exact mechanism of Osteoking are not fully elucidated. In the current study, destabilization of the medial meniscus (DMM)-induced OA mice was introduced as a wild type animal model. After 8 weeks of administration of Osteoking, histomorphometry, OARSI scoring, gait analysis, micro-CT, and immunohistochemical staining for Col2, MMP-13, TGFβRII and pSmad-2 were conducted to evaluate the chondroprotective effects of Osteoking in vivo. Further in vitro experiments were then performed to detect the effect of Osteoking on chondrocytes. TGFβRII^Col2ER transgenic mice were constructed and introduced in the current study to validate whether Osteoking exerts its anti-OA effects via the TGF-β signaling pathway. Results demonstrated that in wild type DMM mice, Osteoking ameliorated OA-phenotype including cartilage degradation, subchondral bone sclerosis, and gait abnormality. Col2, TGFβRII, and pSmad-2 expressions were also found to be up-regulated after Osteoking treatment, while MMP-13 was down-regulated. In vitro, the mRNA expression of MMP-13 and ADAMTS5 decreased and the mRNA expression of Aggrecan, COL2, and TGFβRII were up-regulated after the treatment of Osteoking in IL-1β treated chondrocytes. The additional treatment of SB505124 counteracted the positive impact of Osteoking on primary chondrocytes. In TGFβRII^Col2ER mice, spontaneous OA-liked phenotype was observed and treatment of Osteoking failed to reverse the OA spontaneous progression. In conclusion, Osteoking ameliorates OA progression by decelerating cartilage degradation and alleviating subchondral bone sclerosis partly via the TGF-β signaling pathway.

Matrix Metalloproteinase Inspired Therapeutic Strategies for Bone Diseases

Matrix Metalloproteinases (MMPs), as a family of zinc-containing enzymes, show the function of decomposing Extracellular Matrix (ECM) and participate in the physiological processes of cell migration, growth, inflammation, and metabolism. Clinical and experimental studies have indicated that MMPs play an essential role in tissue injury and repair as well as tumor diagnosis, metastasis, and prognosis. An increasing number of researchers have paid attention to their functions and mechanisms in bone health and diseases. The present review focuses on MMPs-inspired therapeutic strategies for the treatment of bone-related diseases. We introduce the role of MMPs in bone diseases, highlight the MMPs-inspired therapeutic options, and posit MMPs as a trigger for smart cell/drug delivery.

Mediterranean diet and changes in frequency, severity and localization of pain in older adults: The Seniors-ENRICA cohorts

BACKGROUND

Although some components of the Mediterranean diet have shown benefits in pain risk through its anti-inflammatory/antioxidant properties, no population-based studies have investigated the effect of adherence to this diet on changes in pain over time.

METHODS

We used data from 864 and 862 older adults recruited in the Seniors-ENRICA-1 and Seniors-ENRICA-2 cohorts and followed-up for 2.8 and 2.4 years, respectively. Adherence to the Mediterranean diet was assessed with the MEDAS score at baseline. Frequency, severity and locations of pain obtained at baseline and follow-up were used to compute a pain scale. Analyses were performed using multinomial logistic regression models, and adjusted for the main confounders.

RESULTS

Participants had a mean (SD) age of 71.5 (5.1) years, 36.8% were men and 78.3% had chronic conditions. In the pooled cohorts, compared with participants in the lowest quartile of the MEDAS score (lowest adherence to the Mediterranean diet), those in the highest quartile showed a higher frequency of pain improvement versus worsening (relative risk ratio [95% confidence interval]: 1.43 [1.03,1.99]). This association was also evidenced in two components of the pain scale: improvement in pain severity (1.43 [1.01,2.04]) and reduction in pain locations (1.54 [1.08,2.20]), but a tendency to pain frequency improvement (1.34 [0.92,1.93]) was also observed. The main contributors to these associations were high consumption of fruit and vegetables, and low consumption of sugar-sweetened beverages.

CONCLUSIONS

A higher adherence to the Mediterranean diet was related to a subsequent improvement in pain characteristics in older adults, suggesting that improving diet quality may help reduce the high health impact of pain.

Adrenergic signalling in osteoarthritis

Adrenoceptors (ARs) mediate the effects of the sympathetic neurotransmitters norepinephrine (NE) and epinephrine (E) in the human body and play a central role in physiologic and pathologic processes. Therefore, ARs have long been recognized as targets for therapeutic agents, especially in the field of cardiovascular medicine. During the past decades, the contribution of the sympathetic nervous system (SNS) and particularly of its major peripheral catecholamine NE to the pathogenesis of osteoarthritis (OA) attracted growing interest. OA is the most common degenerative joint disorder worldwide and a disease of the whole joint. It is characterized by progressive degradation of articular cartilage, synovial inflammation, osteophyte formation, and subchondral bone sclerosis mostly resulting in chronic pain. The subchondral bone marrow, the periosteum, the synovium, the vascular meniscus and numerous tendons and ligaments are innervated by tyrosine hydroxylase-positive (TH+) sympathetic nerve fibers that release NE into the synovial fluid and cells of all abovementioned joint tissues express at least one out of nine AR subtypes. During the past decades, several in vitro studies explored the AR-mediated effects of NE on different cell types in the joint. So far, only a few studies used animal OA models to investigate the contribution of distinct AR subtypes to OA pathogenesis in vivo. This narrative review shortly summarizes the current background knowledge about ARs and their signalling pathways at first. In the second part, we focus on recent findings in the field of NE-induced AR-mediated signalling in different joint tissues during OA pathogenesis and at the end, we will delineate the potential of targeting the adrenergic signalling for OA prevention or treatment. We used the PubMed bibliographic database to search for keywords such as 'joint' or 'cartilage' or 'synovium' or 'bone' and 'osteoarthritis' and/or 'trauma' and 'sympathetic nerve fibers' and/or 'norepinephrine' and 'adrenergic receptors / adrenoceptors' as well as 'adrenergic therapy'.