Exercise increases interleukin-10 levels both intraarticularly and peri-synovially in patients with knee osteoarthritis: a randomized controlled trial

Usefulness and Safety of a Wearable Transcutaneous Electrical Nerve Stimulation Device for Promoting Exercise Therapy in Patients With Chronic Knee Pain: A Randomized Controlled Trial

OBJECTIVE

To investigate the effect of transcutaneous electrical nerve stimulation (TENS) in reducing barriers to the implementation of exercise therapy and promoting exercise therapy, focusing on physical activity (PA).

DESIGN

A single-center, participant-blinded, randomized controlled trial with a pre-post design.

SETTING

Orthopedic clinic at a single institution,.

PARTICIPANTS

Participants (N=63, aged ≥50y) who had knee pain for ≥3 months were randomly assigned to the TENS (N=21), exercise (N=23), or combined (N=19) groups.

INTERVENTIONS

Participants were provided with 4 weeks of intervention: the TENS group using a wearable TENS device, exercise group performing designated exercises, and combined group performing activities from the TENS and exercise groups.

MAIN OUTCOME MEASURES

The primary outcome measure was PA. The secondary outcome measures were 6-minute walk test (6MWT); timed Up and Go (TUG) test; stair climbing; knee pain using the visual analog scale at 6MWT, TUG test, and stair climbing; and patient-reported changes in knee pain over time.

RESULTS

At pre- and postintervention, light-intensity PA time (minutes per day) in the TENS, exercise, and combined groups was 735.62±68.82 vs 714.21±73.06 (P=.061), 733.05±103.90 vs 700.31±90.33 (P=.057), and 710.09±62.98 vs 685.22±58.35 (P=.049), respectively, with a significant decrease in the combined group. Significant improvement in knee pain and stair climbing was observed in all groups pre- and postintervention.

CONCLUSIONS

The group using TENS showed improved effects of early reduction in knee pain and when combined with exercise therapy, a reduction in time spent in light-intensity activities such as sedentary behavior. Thus, the use of TENS in combination with conventional exercise therapy has the potential to reduce psychological barriers to the introduction of exercise therapy. It also promotes and ensures the safe implementation and continuation of exercise therapy.

Teaming up to overcome challenges toward translation of new therapeutics for osteoarthritis

As a leading global cause of musculoskeletal-related disability, osteoarthritis (OA) represents a public health urgency. Understanding of disease pathogenesis has advanced substantially in the past decade, yet no disease-modifying therapeutics have advanced to the clinic. To address this challenge, the CARE-AP (Cartilage Repair strategies to alleviate Arthritis Pain) collaborative research team was convened to bring together relevant multidisciplinary expertise and perspectives from across the VA research community nationwide. The first CARE-AP Annual Research Symposium took place (virtually) in February 2022 with roughly 90 participants. A number of innovative and therapeutic strategies were discussed, including siRNA approaches coupled with novel nanoparticle-based delivery systems, cellular engineering approaches to develop reparative cells that can probe the joint environment and respond to disease-specific cues, and novel biofabrication techniques to improve tissue engineering and effect "biological joint replacement." In addition, challenges and advances in rehabilitation approaches, imaging outcomes, and clinical studies were presented, which were integrated into a framework of recommendations for running "preclinical trials" to improve successful clinical translation.

The Impact of Weight-bearing Exercise, Non-Weight-bearing Exercise, and Cardiovascular Stress on Biochemical Markers of Cartilage Turnover in Patients With Mild to Moderate Knee Osteoarthritis: A Sequential, Cross-Over, Clinical Study

OBJECTIVE

To investigate how running, cycling, and sedentary cardiovascular stress impact biomarkers of cartilage turnover acutely in subjects with knee osteoarthritis (OA).

DESIGN

This was a sequential, cross-over, clinical study. Forty subjects with primary knee OA underwent moderate-to-high-intensity cycling, running, and adrenaline infusion on separate days. Blood was sampled before, during, and at 6-time points after intervention. On a control day, similar samples were taken. Biomarkers of type II collagen degradation (C2M, T2CM, Coll2-1, Coll2-1NO2), formation (PRO-C2), and aggrecan degradation (ARGS) were measured.

RESULTS

Mean age was 60.4 years, 40% were male, 45% had cumulated Kellgren-Lawrence (KL)-grade (Right + Left knee) of 2 to 3 and 55% had 4 to 6. Analyzing overall changes, area under the curve was significantly lower compared with resting values for ARGS and C2M after cycling and for ARGS after running. Considering individual time points, peak changes in biomarker levels showed reduction in C2M shortly following cycling (T20min = -12.3%, 95% confidence interval [CI]: -19.3% to -5.2%). PRO-C2 increased during cycling (T10min = 14.0%, 95% CI = 4.1% to 23.8%) and running (T20min = 16.5%, 95% CI = 4.3% to 28.6%). T2CM decreased after cycling (T50min = -19.9%, 95% CI = -29.2% to -10.6%), running (T50min = -22.8%, 95% CI = -32.1% to -13.5%), and infusion of adrenaline (peak, T50min = -9.8%, 95% CI = -20.0% to 0.4%). A latent increase was seen in Coll2-1 240 minutes after running (T260min = 21.7%, 95% CI = -1.6% to 45.1%).

CONCLUSION

Exercise had an impact on cartilage markers, but it did not suggest any detrimental effect on cartilage. Changes following adrenaline infusion suggest a sympathomimetic influence on the serological composition of biomarkers.

Hip contact forces can be predicted with a neural network using only synthesised key points and electromyography in people with hip osteoarthritis

OBJECTIVE

To develop and validate a neural network to estimate hip contact forces (HCF), and lower body kinematics and kinetics during walking in individuals with hip osteoarthritis (OA) using synthesised anatomical key points and electromyography. To assess the capability of the neural network to detect directional changes in HCF resulting from prescribed gait modifications.

DESIGN

A calibrated electromyography-informed neuromusculoskeletal model was used to compute lower body joint angles, moments, and HCF for 17 participants with mild-to-moderate hip OA. Anatomical key points (e.g., joint centres) were synthesised from marker trajectories and augmented with bias and noise expected from computer vision-based pose estimation systems. Temporal convolutional and long short-term memory neural networks (NN) were trained using leave-one-subject-out validation to predict neuromusculoskeletal modelling outputs from the synthesised key points and measured electromyography data from 5 hip-spanning muscles.

RESULTS

HCF was predicted with an average error of 13.4 ± 7.1% of peak force. Joint angles and moments were predicted with an average root-mean-square-error of 5.3 degrees and 0.10 Nm/kg, respectively. The NN could detect changes in peak HCF that occur due to gait modifications with good agreement with neuromusculoskeletal modelling (r2 = 0.72) and a minimum detectable change of 9.5%.

CONCLUSION

The developed neural network predicted HCF and lower body joint angles and moments in individuals with hip OA using noisy synthesised key point locations with acceptable errors. Changes in HCF magnitude due to gait modifications were predicted with high accuracy. These findings have important implications for implementation of load-modification based gait retraining interventions for people with hip OA in a natural environment (i.e., home, clinic).

Analysis of the Level of Adiponectin and Selected Cytokines in Patients with Knee Osteoarthritis

Background and Objectives: Knee osteoarthritis (KOA) is a degenerative disease that is continuously targeting people of different ages, but especially the elderly population, the number of which tends to increase continuously at the global level. Apart from age, excess weight can influence the evolution of the disease, with obesity being associated with a weak inflammation stage and an imbalance between pro-inflammatory and anti-inflammatory cytokines. The present work aimed to analyze specific biomarkers, namely ACRP-30, IL-10, TNF-α, and IL-6, in knee synovial fluid, and correlate them with KOA patients' clinical data, radiographic changes, and functional and pain scores. Materials and Methods: 24 subjects with KOA and over 50 years of age participate in the present study. Synovial fluid was harvested using ultrasound guidance from the target knees of the enrolled KOA patients, and the levels of ACRP-30, IL-10, TNF-α, and IL-6 were measured using enzyme-linked immunosorbent assays (ELISA). All patients underwent a supine X-ray at the target knee and were classified using Kellgren-Lawrence (K-L) grading. The Western Ontario and McMaster University Osteoarthritis Index (WOMAC) was used to assess self-reported physical function, pain, and stiffness. Results: The obtained results highlighted a significant correlation between age and adiponectin level (p = 0.0451, r = -0.412). Also, the IL-10 values are lower in cases where the intensity of the pain is more pronounced (p = 0.0405, r = -0.421). In addition, analyzing the data by gender, it was observed that in the case of males, stiffness is more related to age (p = 0.0079, r = 0.7993), compared to women (p = 0.0203, r = 0.6223). In the case of women, the progression of the disease tends to increase more intensively the WOMAC score's total values (p = 0.00031, r = 0.8342), compared with men (p = 0.0289, r = 7013). Regarding interleukins and BMI, significant correlations were observed only in the case of men. Conclusions: A significant correlation between age and adiponectin, and adiponectin and IL-6, suggests that advanced age may contribute to adiponectin reduction. Comparing men with women, it was observed that men's age is more related to rigidity, and IL-6 and IL-10 are directly correlated to BMI; in addition, women seem to be more sensitive to pain and stiffness.

Osteoarthritis year in review 2023: Biomechanics

Biomechanics plays a significant yet complex role in osteoarthritis (OA) onset and progression. Identifying alterations in biomechanical factors and their complex interactions is critical for gaining new insights into OA pathophysiology and identification of clearly defined and modifiable mechanical treatment targets. This review synthesized biomechanics studies from March 2022 to April 2023, from which three themes relating to human gait emerged: (1) new insights into the pathogenesis of OA using computational modeling and machine learning, (2) technology-enhanced biomechanical interventions for OA, and (3) out-of-lab biomechanical assessments of OA. We further highlighted future-focused areas which may continue to advance the field of biomechanics in OA, with a particular emphasis on exploiting technology to understand and treat biomechanical mechanisms of OA outside the laboratory. The breadth of studies included in this review highlights the complex role of biomechanics in OA and showcase numerous innovative and outstanding contributions to the field. Exciting cross-disciplinary efforts integrating computational modeling, mobile sensors, and machine learning methods show great promise for streamlining in vivo multi-scale biomechanics workflows and are expected to underpin future breakthroughs in the understanding and treatment of biomechanics in OA.

Exercise therapy for knee osteoarthritis pain: how does it work? A study protocol for a randomised controlled trial

INTRODUCTION

Muscle strengthening training (MST) and behavioural graded activity (BGA) show comparable effects on knee osteoarthritic (KOA) pain, but the mechanisms of action remain unclear. Both exercise-induced anti-inflammation and central sensitisation are promising pathways for pain relief in response to exercise therapy in patients with KOA: MST has the potential to decrease inflammation and BGA has the potential to decrease central sensitisation. Hence, this study aims to examine inflammation and central sensitisation as mediators for the effect of MST and/or BGA on pain in patients with KOA.

METHODS AND ANALYSIS

The Knee OsteoArthritis PAIN trial started on 10 January 2020 (anticipated end: April 2024). The three-arm clinical trial aims to recruit 90 KOA patients who will be randomly allocated to 12 weeks of (1) MST, (2) BGA or (3) care as usual. Assessments will be performed at baseline, 13 and 52 weeks after finishing the intervention. Outcomes, including pain (Knee injury and Osteoarthritis Outcome Score), were chosen in line with the OARSI recommendations for clinical trials of rehabilitation interventions for OA and the IMMPACT/OMERACT recommendations for the assessment of physical function in chronic pain clinical trials. Inflammation as well as features of central sensitisation (including conditioned pain modulation, offset analgesia, temporal summation of pain and event-related potentials following electrical stimulation), will be considered as treatment mediators. A multiple mediators model will be estimated with a path-analysis using structural equation models. In July 2023, all 90 KOA patients have been included and 42 participants already finished the study.

ETHICS AND DISSEMINATION

This study obtained ethics approval (B.U.N. 143201941843). Unravelling the mechanisms of action of exercise therapy in KOA will not only be extremely valuable for researchers, but also for exercise immunology and pain scientists and clinicians.

TRIAL REGISTRATION NUMBER

NCT04362618.

Effectiveness of lower limb rehabilitation protocol using mobile health on quality of life, functional strength, and functional capacity among knee osteoarthritis patients who are overweight and obese: A randomized-controlled trial

Objectives

This study aims to investigate the effectiveness of the lower limb rehabilitation protocol (LLRP) using mobile health (mHealth) on quality of life (QoL), functional strength, and functional capacity among knee OA patients who were overweight and obese.

Patients and methods

Between August 2019 and November 2020, a total of 96 patients (42 males, 54 females; mean age; 52.9±4.8 years; range, 40 to 60 years) were randomized into either the rehabilitation group with mobile health (RGw-mHealth) receiving reminders by using mHealth to carry on the strengthening exercises of LLRP and instructions of daily care (IDC), the rehabilitation group without mobile health (RGwo-mHealth) following the strengthening exercises of LLRP and instructions of daily care (IDC) and control group (CG) only following the IDC for duration of 12 weeks. The reminders for using mHealth were provided two times a day for three days a week. Primary outcome measures were QoL assessed by the Western Ontario and McMaster Universities Osteoarthritis Index summary score, and functional strength by five-repetition sit-to-stand test. Secondary outcome measure was functional capacity assessed by the Gait Speed Test. The assessments of QoL, functional strength, and functional capacity were taken at baseline and post-test after 12 weeks of intervention.

Results

After 12 weeks of intervention, the patients in all three groups had a statistically significant improvement in QoL within groups (p<0.05). Patients in the RGw-mHealth and RGwo-mHealth had a statistically significant improvement in functional strength and walking gait speed within groups (p<0.05). The pairwise between-group comparisons (Bonferroni post-hoc test) of the mean changes in QoL, functional strength, and functional capacity at post-test assessments revealed that patients in the RGw-mHealth had a statistically significant greater mean change in QoL, functional strength and functional capacity relative to both the RGwo-mHealth and CG (p<0.001).

Conclusion

The improvement in QoL, functional strength, and functional capacity was greater among patients in the RGw-mHealth compared to the RGwo-mHealth or CG.

Joint biomarker response to mechanical stimuli in osteoarthritis - A scoping review

Objective

Arthritic cartilage is primed for mechanical damage. Joint biochemical markers (JBM) could provide insight into the impact of mechanical stimulation on joint tissue turnover in osteoarthritis (OA) of potential use in clinical OA research and practice. However, existing studies of the acute impact of physical activities (PA) on JBM often contain risks of substantial bias. The purpose of this scoping review was to critically review and discuss existing reports of acute joint tissue turnover as reflected in JBM in relation to PA in OA and propose considerations for future research.

Design

We searched PubMed, Embase, and Scopus and reference lists for original reports on the acute impact of PA on JBM in human OA. Identified studies were reviewed by two reviewers forming the basis for the discussion of methodology.

Results

Search in databases resulted in nine eligible papers after full-text evaluation. Two additional papers were identified through reference lists, resulting in 11 papers included in this review. Ten investigated knee OA and one investigated hand OA. Biomarkers described were related to turnover of type II collagen, aggrecan, and cartilage oligomeric matrix protein.

Conclusions

The literature is dominated by small, simplistic studies, but suggests that mechanical stimulation can induce acute changes in joint biomarkers. In order to diminish the existing bias in future studies, it is important to recognize methodological considerations e.g. patient and biomarker selection as well as peri-interventional control. Common potential sources of bias include the acute shift in plasma volume due to cardiovascular stress and postural changes.

The Effect of Moderate-Intensity Physical Exercise on Some Serum Inflammation Markers and the Immune System in Rats Fed Intermittent Fasting with a High-Fat Diet

Background and Objectives: This study aimed to investigate the impact of moderate-intensity physical exercise on serum inflammation markers and the immune system in rats that were fed a high-fat diet (HFD) with intermittent fasting. Materials and Methods: A total of 48 Wistar albino male rats were included in the study and divided into eight groups, each consisting of six rats. Group 1 served as the control group (CG), receiving a standard diet. Group 2 followed the standard nutrition program with intermittent fasting (CG + IF). Group 3 underwent exercise with a standard diet (CG + E). Group 4 underwent both a standard diet with intermittent fasting and exercise (CG + IF + E). Group 5 was fed a high-fat diet (HFD). Group 6 received a high-fat diet with intermittent fasting (HFD + IF). Group 7 followed a high-fat diet with exercise (HFD + E). Group 8 underwent both a high-fat diet with intermittent fasting and exercise (HFD + IF + E). The study lasted for 8 weeks. Results: The results of the analysis show that lymphocyte cell levels in groups HFD + IF, HFD + IF, and HFD + IF + E were higher compared to groups CG-HFD (p < 0.05). Additionally, B lymphocyte and monocyte cell levels were higher in group HFD + IF + E compared to groups CG, CG + IF, and CG + IF + E, as well as CG, CG + IF, and CG + E, respectively. TNF-α levels were significantly higher in group HFD compared to the other groups. Furthermore, IL 10 levels were higher in group HFD + IF + E compared to the other groups. Conclusions: These findings indicate that moderate exercise and intermittent fasting, particularly in groups fed a high-fat diet, increased anti-inflammatory cytokine levels, and certain immune system cell counts, while decreasing pro-inflammatory cytokine levels.

A clinical model to predict the progression of knee osteoarthritis: data from Dryad

BACKGROUND

Knee osteoarthritis (KOA) is a multifactorial, slow-progressing, non-inflammatory degenerative disease primarily affecting synovial joints. It is usually induced by advanced age and/or trauma and eventually leads to irreversible destruction of articular cartilage and other tissues of the joint. Current research on KOA progression has limited clinical application significance. In this study, we constructed a prediction model for KOA progression based on multiple clinically relevant factors to provide clinicians with an effective tool to intervene in KOA progression.

METHOD

This study utilized the data set from the Dryad database which included patients with Kellgren-Lawrence (KL) grades 2 and 3. The KL grades was determined as the dependent variable, while 15 potential predictors were identified as independent variables. Patients were randomized into training set and validation set. The training set underwent LASSO analysis, model creation, visualization, decision curve analysis and internal validation using R language. The validation set is externally validated and F1-score, precision, and recall are computed.

RESULT

A total of 101 patients with KL2 and 94 patients with KL3 were selected. We randomly split the data set into a training set and a validation set by 8:2. We filtered "BMI", "TC", "Hypertension treatment", and "JBS3 (%)" to build the prediction model for progression of KOA. Nomogram used to visualize the model in R language. Area under ROC curve was 0.896 (95% CI 0.847-0.945), indicating high discrimination. Mean absolute error (MAE) of calibration curve = 0.041, showing high calibration. MAE of internal validation error was 0.043, indicating high model calibration. Decision curve analysis showed high net benefit. External validation of the metabolic syndrome column-line graph prediction model was performed by the validation set. The area under the ROC curve was 0.876 (95% CI 0.767-0.984), indicating that the model had a high degree of discrimination. Meanwhile, the calibration curve Mean absolute error was 0.113, indicating that the model had a high degree of calibration. The F1 score is 0.690, the precision is 0.667, and the recall is 0.714. The above metrics represent a good performance of the model.

CONCLUSION

We found that KOA progression was associated with four variable predictors and constructed a predictive model for KOA progression based on the predictors. The clinician can intervene based on the nomogram of our prediction model.

KEY INFORMATION

This study is a clinical predictive model of KOA progression. KOA progression prediction model has good credibility and clinical value in the prevention of KOA progression.

Molecular Assessment of Healthy Pathological Articular Cartilages in Physically Active People: A Scoping Review

Physiological aging triggers a cascade of negative effects on the human body and the human joint is only one of the several compartments affected by this irreversible and natural process. Osteoarthritis and cartilage degeneration can cause pain and disability; therefore, identifying the molecular processes underlying these phenomena and the biomarkers produced during physical activity is of critical importance. In the present review, the main goal was to identify and discuss the articular cartilage biomarkers analyzed in studies in which physical or sports activities were adopted and eventually to propose a standard operating procedure for the assessment. Articles collected from Pubmed, Web of Science, and Scopus were scrutinized to detect reliable cartilage biomarkers. The principal articular cartilage biomarkers detected in these studies were cartilage oligomeric matrix protein, matrix metalloproteinases, interleukins, and carboxy-terminal telopeptide. The articular cartilage biomarkers identified in this scoping review may aid in a better comprehension of where research on the topic is heading and offer a viable instrument for streamlining investigations on cartilage biomarker discovery.

Acute loading has minor influence on human articular cartilage gene expression and glycosaminoglycan composition in late-stage knee osteoarthritis: a randomised controlled trial

OBJECTIVE

Osteoarthritis (OA) remains clinically challenging. Regular physical exercise improves symptoms though it is unclear whether exercise influences cartilage at the molecular level. Thus, we aimed to determine the effect of acute loading on gene expression and glycosaminoglycan (GAG) content in human OA cartilage.

DESIGN

Patients with primary knee OA participated in this single-blind randomised controlled trial initiated 3.5 h prior to scheduled joint replacement surgery with or without loading by performing one bout of resistance exercise (one-legged leg press). Cartilage from the medial tibia condyle was sampled centrally, under the meniscus, and from peripheral osteophytes. Samples were analysed for gene expression by real-time reverse transcriptase polymerase chain reaction, and hyaluronidase-extracted matrix was analysed for GAG composition by immuno- and dimethyl-methylene blue assays.

RESULTS

Of 32 patients randomised, 31 completed the intervention: mean age 69 ± 7.5 years (SD), 58% female, BMI 29.4 ± 4.4 kg/m². Exercise increased chondroitin sulphate extractability [95% CI: 1.01 to 2.46; P = 0.0486] but cartilage relevant gene expression was unchanged. Regionally, the submeniscal area showed higher MMP-3, MMP-13, IGF-1Ea, and CTGF, together with lower lubricin and COMP expression compared to the central condylar region. Further, osteophyte expression of MMP-1, MMP-13, IGF-1Ea, and TGF-β3 was higher than articular cartilage and lower for aggrecan, COMP, and FGF-2. Hyaluronidase-extracted matrix from central condylar cartilage contained more GAGs but less chondroitin sulphate compared to submeniscal cartilage.

CONCLUSION

Acute exercise had minor influence on cartilage GAG dynamics, indicating that osteoarthritic cartilage is not significantly affected by acute exercise. However, the regional differences suggest a chronic mechanical influence on human cartilage.

CLINICALTRIALS

GOV REGISTRATION NUMBER

NCT03410745.

Influence of routine exercise on the peripheral immune system to prevent and alleviate pain

Routine physical activity reduces the onset of pain and exercise is a first line treatment for individuals who develop chronic pain. In both preclinical and clinical research regular exercise (routine exercise sessions) produces pain relief through multiple mechanisms such as alterations in the central and peripheral nervous system. More recently, it has been appreciated that exercise can also alter the peripheral immune system to prevent or reduce pain. In animal models, exercise can alter the immune system at the site of injury or pain model induction, in the dorsal root ganglia, and systemically throughout the body to produce analgesia. Most notably exercise shows the ability to dampen the presence of pro-inflammatory immune cells and cytokines at these locations. Exercise decreases M1 macrophages and the cytokines IL-6, IL-1β, and TFNα, while increasing M2 macrophages and the cytokines IL-10, IL-4, and IL-1ra. In clinical research, a single bout of exercise produces an acute inflammatory response, however repeated training can lead to an anti-inflammatory immune profile leading to symptom relief. Despite the clinical and immune benefits of routine exercise, the direct effect of exercise on immune function in clinical pain populations remains unexplored. This review will discuss in more detail the preclinical and clinical research which demonstrates the numerous ways through which multiple types of exercise alter the peripheral immune system. This review closes with the clinical implications of these findings along with suggestions for future research directions.

Effects of a single exercise session on pain intensity in adults with chronic pain: a systematic review and meta-analysis

BACKGROUND

Chronic pain is prevalent amongst society, making it necessary to find strategies to manage chronic pain. Regular exercise is efficacious; however, pain is a barrier to initiating exercise. A single exercise session is also believed to acutely reduce pain, however, the evidence for this is less robust.

OBJECTIVES

This systematic review and meta-analysis aimed to identify the effect of a single exercise session on pain intensity in adults with chronic pain.

METHODS

We searched eight databases and trial registries to identify randomised controlled trials evaluating the effect of a single exercise session on pain intensity in adults with chronic pain compared to a non-exercise control. Literature screening, data extraction, risk of bias (Cochrane 2.0) and quality assessment (GRADE) were conducted independently and in duplicate. Random-effects meta-analyses were performed using the metafor package in R.

RESULTS

We included 17 trials (46 study arms with 664 adults [44% female]). There were no significant differences in pain intensity (mean difference on a 0-10 scale) immediately post-exercise -0.02 (95% CI = -0.06, 0.62; I² = 77.1%) or up to 45-min post-exercise -0.17 (95% CI = -0.49, 0.16; I² = 34.2%). All trials were at high risk of bias and the overall confidence in these findings was very low.

CONCLUSION

A single exercise session did not reduce pain intensity up to 1-h post-exercise. Notably, increases in pain were not observed either, suggesting that while pain can be a barrier to initiating exercise, clinicians can educate patients on the unlikelihood of exercise acutely increasing pain intensity.

Impact of cancer cachexia on respiratory muscle function and the therapeutic potential of exercise

Cancer cachexia is defined as a multi-factorial syndrome characterised by an ongoing loss of skeletal muscle mass and progressive functional impairment, estimated to affect 50-80% of patients and responsible for 20% of cancer deaths. Elevations in the morbidity and mortality rates of cachectic cancer patients has been linked to respiratory failure due to atrophy and dysfunction of the ventilatory muscles. Despite this, there is a distinct scarcity of research investigating the structural and functional condition of the respiratory musculature in cancer, with the majority of studies exclusively focusing on limb muscle. Treatment strategies are largely ineffective in mitigating the cachectic state. It is now widely accepted that an efficacious intervention will likely combine elements of pharmacology, nutrition and exercise. However, of these approaches, exercise has received comparatively little attention. Therefore, it is unlikely to be implemented optimally, whether in isolation or combination. In consideration of these limitations, the current review describes the mechanistic basis of cancer cachexia and subsequently explores the available respiratory- and exercise-focused literature within this context. The molecular basis of cachexia is thoroughly reviewed. The pivotal role of inflammatory mediators is described. Unravelling the mechanisms of exercise-induced support of muscle via antioxidant and anti-inflammatory effects in addition to promoting efficient energy metabolism via increased mitochondrial biogenesis, mitochondrial function and muscle glucose uptake provide avenues for interventional studies. Currently available pre-clinical mouse models including novel transgenic animals provide a platform for the development of multi-modal therapeutic strategies to protect respiratory muscles in people with cancer.

How Physical Activity Affects Knee Cartilage and a Standard Intervention Procedure for an Exercise Program: A Systematic Review

(1) Background: Cartilage degeneration with the natural aging process and the role of physical activity on cartilage wellness is still not clear. The objective of the present review was to understand how different physical activity interventions affect the cartilage and to propose a Standard Operating Procedure for an exercise program to maintain knee joint health; (2) Methods: Articles were collected on three different electronic databases and screened against the eligibility criteria. Results were collected in tables and the main outcomes were discussed narratively; (3) Results: A total of 24 studies have been included after the screening process and aerobic, strength, flexibility, postural balance, and mobility interventions were detected. Different protocols and types of interventions were adopted by the authors; (4) Conclusions: Physical activity interventions have mainly positive outcomes on cartilage structure, but the protocols adopted are different and various. A Standard Operating Procedure has been proposed for a physical intervention focalized on cartilage wellness that could be adopted as an intervention in the clinical setting. Furthermore, the creation of a standardized protocol wants to help scientific research to move in the same direction.

In vitro Exposure to Inflammatory Mediators Affects the Differentiation of Mesenchymal Progenitors

The increasing prevalence of joint disease, and in particular osteoarthritis (OA), calls for novel treatment strategies to prevent disease progression in addition to existing approaches focusing mainly on the relief of pain symptoms. The inherent properties of mesenchymal stem cells (MSCs) make them an attractive candidate for novel tissue repair strategies, as these progenitors have the potential to differentiate into chondrocytes needed to replace degraded cartilage and can exert a modulating effect on the inflammatory environment of the diseased joint. However, the inflammatory environment of the joint may affect the ability of these cells to functionally integrate into the host tissue and exert beneficial effects, as hinted by a lack of success seen in clinical trials. Identification of factors and cell signalling pathways that influence MSC function is therefore critical for ensuring their success in the clinic, and here the effects of inflammatory mediators on bone marrow-derived MSCs were evaluated. Human MSCs were cultured in the presence of inflammatory mediators typically associated with OA pathology (IL-1β, IL-8, IL-10). While exposure to these factors did not produce marked effects on MSC proliferation, changes were observed when the mediators were added under differentiating conditions. Results collected over 21 days showed that exposure to IL-1β significantly affected the differentiation response of these cells exposed to chondrogenic and osteogenic conditions, with gene expression analysis indicating changes in MAPK, Wnt and TLR signalling pathways, alongside an increased expression of pro-inflammatory cytokines and cartilage degrading enzymes. These results highlight the value of MSCs as a preclinical model to study OA and provide a basis to define the impact of factors driving OA pathology on the therapeutic potential of MSCs for novel OA treatments.

Serum netrin-1 and netrin receptor levels in fibromyalgia and osteoarthritis

Objectives: This study aims to define serum levels of netrin-1 and netrin receptors in patients with fibromyalgia (FM) and osteoarthritis (OA).

Patients and methods: This cross-sectional study was conducted with a total of 150 female participants (mean age: 47.2±16.1 years; range, 18 to 89 years) at Fırat University between June 2016 and December 2016. The participants were evaluated in three groups: the FM group with 50 patients, the OA group with 50 patients, and the control group, which included 50 healthy volunteers. Netrin-1, netrin receptors (DCC, UNC5B, and UNC5D), interleukin (IL)-6, IL-10, and IL-17 levels were analyzed by the enzyme-linked immunosorbent assay from the serum samples of the participants.

Results: The level of serum netrin-1 was significantly lower in the FM group than in the control and OA groups (p<0.01 and p<0.001, respectively). However, the difference between patients with OA and healthy controls in terms of netrin-1 was not statistically significant (p>0.05). In addition, serum levels of netrin receptors and cytokines in the FM group were similar to the control group (p>0.05). However, serum DCC, UNC5D, IL-6, and IL-10 levels were higher in the OA group compared to the control group (p<0.001, p<0.05, p<0.01, and p<0.001, respectively).

Conclusion: Serum netrin-1 level is suppressed in FM, which suggests that netrin-1 is influential in FM pathogenesis.

The preventive and therapeutic role of physical activity in knee osteoarthritis

The aim of this narrative review is to discuss the results of studies investigating the role of physical activity in knee osteoarthritis (OA). We also formulated two evidence-based exercise programs that could be prescribed to patients with symptomatic knee OA or after joint replacement. The PubMed and Google Scholar databases were searched for articles related to knee OA and physical activity. A total of 86 papers written in English and published from 1957 to 2021 were selected. Adapted physical activity, even at high intensity, does not appear to trigger or exacerbate knee OA; on the contrary, it may prevent obesity or lower limb muscle weakness, both of which are considered predisposing factors for the disease. In patients already diagnosed with knee OA, scientific evidence suggests that both land-based and aquatic activities combining aerobics, strength, and endurance programs are safe and effective. Physical interventions tailored to the patient may also accelerate recovery time after knee arthroplasty. Knee OA is a painful and disabling rheumatic disease that is very common in the elderly population. Pharmacotherapy has a modest effect in controlling disease progression, possibly due to the still limited understanding of OA pathogenesis. Non-pharmacologic interventions, including dietary and lifestyle changes and physical activity, may be more effective and safer than drugs in preventing or treating knee OA.

Synovial inflammation in osteoarthritis progression

Osteoarthritis (OA) is a progressive degenerative disease resulting in joint deterioration. Synovial inflammation is present in the OA joint and has been associated with radiographic and pain progression. Several OA risk factors, including ageing, obesity, trauma and mechanical loading, play a role in OA pathogenesis, likely by modifying synovial biology. In addition, other factors, such as mitochondrial dysfunction, damage-associated molecular patterns, cytokines, metabolites and crystals in the synovium, activate synovial cells and mediate synovial inflammation. An understanding of the activated pathways that are involved in OA-related synovial inflammation could form the basis for the stratification of patients and the development of novel therapeutics. This Review focuses on the biology of the OA synovium, how the cells residing in or recruited to the synovium interact with each other, how they become activated, how they contribute to OA progression and their interplay with other joint structures.

Exercise to Mend Aged-tissue Crosstalk in Bone Targeting Osteoporosis & Osteoarthritis

Aging induces alterations in bone structure and strength through a multitude of processes, exacerbating common aging- related diseases like osteoporosis and osteoarthritis. Cellular hallmarks of aging are examined, as related to bone and the marrow microenvironment, and ways in which these might contribute to a variety of age-related perturbations in osteoblasts, osteocytes, marrow adipocytes, chondrocytes, osteoclasts, and their respective progenitors. Cellular senescence, stem cell exhaustion, mitochondrial dysfunction, epigenetic and intracellular communication changes are central pathways and recognized as associated and potentially causal in aging. We focus on these in musculoskeletal system and highlight knowledge gaps in the literature regarding cellular and tissue crosstalk in bone, cartilage, and the bone marrow niche. While senolytics have been utilized to target aging pathways, here we propose non-pharmacologic, exercise-based interventions as prospective "senolytics" against aging effects on the skeleton. Increased bone mass and delayed onset or progression of osteoporosis and osteoarthritis are some of the recognized benefits of regular exercise across the lifespan. Further investigation is needed to delineate how cellular indicators of aging manifest in bone and the marrow niche and how altered cellular and tissue crosstalk impact disease progression, as well as consideration of exercise as a therapeutic modality, as a means to enhance discovery of bone-targeted therapies.

Effects of different courses of moxibustion treatment on intestinal flora and inflammation of a rat model of knee osteoarthritis

OBJECTIVE

This study was done to determine the effects of different courses of moxibustion on a rat knee osteoarthritis (KOA) model, and explore the dose-effect relationship of moxibustion on KOA from the perspectives of intestinal flora and inflammatory factors.

METHODS

Wistar rats were randomly divided into five groups: normal, model, moxibustion for 2 weeks, moxibustion for 4 weeks and moxibustion for 6 weeks groups (n = 5 each group). A KOA rat model was induced by monosodium iodoacetate, and moxibustion intervention was performed at the acupoints "Dubi" (ST35) and "Zusanli" (ST36), once every other day. Pathologic changes in the cartilage of rat knee joints were assessed after intervention, and fecal samples were subjected to 16S rRNA high-throughput sequencing for microbial diversity analysis.

RESULTS

Damage to the knee articular cartilage was obvious in the model group, which also had increased levels of pro-inflammatory factors, decreased levels of anti-inflammatory factors, and intestinal flora disorders with decreased diversity. The degree of cartilage damage in the 4 and 6 weeks of moxibustion groups was significantly improved compared with the model group. The 4 and 6 weeks of moxibustion groups also demonstrated reduced levels of interleukin-1β and tumor necrosis factor-α and increased levels of interleukin-10 (P < 0.05). Both the abundance and diversity of the intestinal flora were increased, approaching those of the normal group. Abundances of probiotics Eubacterium coprostanoligenes group and Ruminococcaceae UCG-014 increased, while that of the pathogenic bacteria Lachnospiraceae NK4A136 group decreased (P < 0.05). Although the abundance of Lachnospiraceae NK4A136 group decreased in the 2 weeks of moxibustion group compared with the model group (P < 0.05), there was no statistically significant difference in serum inflammatory factors, flora species diversity or degree of pathological damage compared with the model group.

CONCLUSION

Moxibustion treatment led to significant improvements in the intestinal flora and inflammatory factors of rats with KOA. Moxibustion treatment of 4 and 6 weeks led to better outcomes than the 2-week course. Moxibustion for 4 and 6 weeks can regulate intestinal flora dysfunction with increased probiotics and reduced pathogenic bacteria, reduce pro-inflammatory factors and increase anti-inflammatory factors. No significant differences were seen between the effects of moxibustion for 4 weeks and 6 weeks.

Short-Term Effects of Strengthening Exercises of the Lower Limb Rehabilitation Protocol on Pain, Stiffness, Physical Function, and Body Mass Index among Knee Osteoarthritis Participants Who Were Overweight or Obese: A Clinical Trial

BACKGROUND

Osteoarthritis (OA) of the knee is defined as a progressive disease of the synovial joints and is characterized by wear and tear of the cartilage and underlying bone. This study aimed to determine the short-term effects of the lower limb rehabilitation protocol (LLRP) on pain, stiffness, physical function, and body mass index (BMI) among knee OA participants who were overweight or obese. Methodology. A single-blinded randomized controlled trial of one-month duration was conducted at Rehmatul-Lil-Alameen Postgraduate Institute, Lahore, Pakistan. Fifty overweight or obese participants with knee OA were randomly divided into two groups by a computer-generated number. Participants in the rehabilitation protocol group (RPG) were provided with leaflets explaining the strengthening exercises of the LLRP and instruction of daily care (IDC), while the participants in the control group (CG) were provided with leaflets explaining the IDC only for a duration of four weeks. The primary outcome measures were the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores for pain, stiffness, and physical function. The secondary outcome measures were BMI, exercise adherence, and patients' satisfaction assessed by using the numeric rating scale ranging from 0 to 10. The paired-sample t-test was used to analyze the differences within groups from baseline to posttest evaluations. The analysis of variance 2 × 2 factor was used to analyze the differences in BMI, knee pain, stiffness, and physical function between the groups.

RESULTS

Participants in the RPG and CG reported a statistically significant reduction in knee pain and stiffness (p ≤ 0.05) within the group. The reduction in the scores of knee pain was higher in participants in the RPG than that in participants in the CG (p=0.001). Additionally, participants in the RPG reported greater satisfaction (p=0.001) and higher self-reported exercise adherence (p=0.010) and coordinator-reported exercise adherence (p=0.046) than the participants in the CG.

CONCLUSION

Short-term effects of the LLRP appear to reduce knee pain and stiffness only, but not physical function and BMI.

Distribution and Appearance of Ki-67, IL-1α, IL-10, and PGP 9.5 in Reinke's Oedema-Affected Larynx Tissue Compared with Control Tissue

Smoking, laryngopharyngeal reflux, and vocal fold abuse can promote the development of Reinke’s oedema, leading to vocal fold dysfunction and injury. The aim of the work was to investigate the appearance and distribution of proliferation marker Ki-67 (Ki-67), interleukin 10 (IL-10), interleukin 1 alpha (IL-1α), and protein gene peptide 9.5 (PGP 9.5) in Reinke’s oedema-affected larynx tissue. Methods: A routine histological and immunohistochemical Reinke’s oedema and control group patient analysis was conducted. We used the biotin–streptavidin biochemical method to detect Ki-67, IL-10, IL-1α, and PGP 9.5 The semiquantitative grading method was used to evaluate immunoreactive cells’ appearance and local distribution. A Mann–Whitney U test and Spearman’s rank coefficient were performed. Results: A low positive correlation between IL-1α epithelial and subepithelial immunoreactive cells in the patient group was found. Mann–Whitney U tests revealed significant patient and control group immunoreactive marker differences. All examined markers showed a higher number of immunoreactive structures in the patient group. Conclusions: Intensive proliferation of the surface epithelium was observed in patient tissues. The notable increase in IL-10 positive structures indicates the dominant anti-inflammatory tissue response. An increased number of IL-1α structures in the larynx epithelium and subepithelium in the patient group is linked to inflammation, proliferation, and tissue remodelling. The PGP 9.5 expression increase is involved in the morphopathogenesis of Reinke’s oedema.

Synovial Fluid Biomarkers in Knee Osteoarthritis: A Systematic Review and Quantitative Evaluation Using BIPEDs Criteria

OBJECTIVE

The aim of this systematic review was to analyze the evidence about the efficacy of the several synovial fluid (SF) biomarkers proposed for knee osteoarthritis (OA), categorizing them by both molecular characteristics and clinical use according to the BIPEDs criteria, to provide a comprehensive and structured overview of the current literature.

DESIGN

A systematic review was performed in May 2020 on PubMed, Cochrane Library, and Embase databases about SF biomarkers in patients with knee OA. The search was limited to articles in the last 20 years on human studies, involving patients with knee OA, reporting SF biomarkers. The evidence for each selected SF biomarker was quantified according to the 6 categories of BIPEDs classification.

RESULTS

A total of 159 articles were included in the qualitative data synthesis and 201 different SF biomarkers were identified. Among these, several were investigated multiple times in different articles, for a total of 373 analyses. The studies included 13,557 patients with knee OA. The most promising SF biomarkers were C4S, IL-6, IL-8, Leptin, MMP-1/3, TIMP-1, TNF-α, and VEGF. The "burden of disease" and "diagnostic" categories were the most represented with 132 and 106 different biomarkers, respectively.

CONCLUSIONS

The systematic review identified numerous SF biomarkers. However, despite the high number of studies on the plethora of identified molecules, the evidence about the efficacy of each biomarker is supported by limited and often conflicting findings. Further research efforts are needed to improve the understanding of SF biomarkers for a better management of patients with knee OA.

Effects of isometric contraction of the quadriceps on the hardness and blood flow in the infrapatellar fat pad

[Purpose] This study aimed to clarify the influence of the isometric contraction of the quadriceps (ICQ) with low intensity on the circulation in the infrapatellar fat pad (IFP). [Participants and Methods] The participants were 7 males and 5 females, with an average age of 21.5 ± 1.4 years. IFP hardness was measured using shear wave ultrasound elastography and Biodex. Tissue oxygenation was measured via near-infrared spectroscopy using oxygenated hemoglobin (O2Hb), deoxygenated hemoglobin (HHb), and total hemoglobin (cHb) as indices. The mean values were calculated for three periods: 1 min of rest immediately before the exercise task (before ICQ), the lower limit of the 10 sets during the exercise task (during ICQ), and 3–4 min after the exercise task (after ICQ). IFP hardness was compared between resting conditions and ICQ, and tissue oxygenation was compared before, during, and after ICQ. [Results] ICQ significantly increased IFP hardness. Tissue hemoglobin, O2Hb, and cHb decreased significantly during ICQ and increased after ICQ compared to that before ICQ. HHb decreased during ICQ and recovered significantly after ICQ. [Conclusion] In healthy participants, low-intensity ICQ increases the hardness and oxygenation of the IFP. This study may partly explain the unknown pain relief mechanism of exercise therapy.

Effects of photobiomodulation and a physical exercise program on the expression of inflammatory and cartilage degradation biomarkers and functional capacity in women with knee osteoarthritis: a randomized blinded study

BACKGROUND

The knee osteoarthritis (OA) is a joint disease characterized by degradation of articular cartilage that leads to chronic inflammation. Exercise programs and photobiomodulation (PBM) are capable of modulating the inflammatory process of minimizing functional disability related to knee OA. However, their association on the concentration of biomarkers related to OA development has not been studied yet. The aim of the present study is to investigate the effects of PBM (via cluster) with a physical exercise program in functional capacity, serum inflammatory and cartilage degradation biomarkers in patients with knee OA.

METHODS

Forty-two patients were randomly allocated in 3 groups: ESP: exercise + sham PBM; EAP: exercise + PBM and CG: control group. Six patients were excluded before finished the experimental period. The analyzed outcomes in baseline and 8-week were: the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) and the evaluation of serum biomarkers concentration (IL-1β, IL-6, IL-8, IL-10 e TNF-α, and CTX-II).

RESULTS

An increase in the functional capacity was observed in the WOMAC total score for both treated groups (p < 0.001) and ESP presents a lower value compared to CG (p < 0.05) the 8-week post-treatment. In addition, there was a significant increase in IL-10 concentration of EAP (p < 0.05) and higher value compared to CG (p < 0.001) the 8-week post-treatment. Moreover, an increase in IL-1β concentration was observed for CG (p < 0.05). No other difference was observed comparing the other groups.

CONCLUSION

Our data suggest that the physical exercise therapy could be a strategy for increasing functional capacity and in association with PBM for increasing IL-10 levels in OA knee individuals.

TRIAL REGISTRATION

ReBEC (RBR-7t6nzr).

The EPIPHA-KNEE trial: Explaining Pain to target unhelpful pain beliefs to Increase PHysical Activity in KNEE osteoarthritis - a protocol for a multicentre, randomised controlled trial with clinical- and cost-effectiveness analysis

Background

Despite well-established benefits of physical activity for knee osteoarthritis (OA), nine of ten people with knee OA are inactive. People with knee OA who are inactive often believe that physical activity is dangerous, fearing that it will further damage their joint(s). Such unhelpful beliefs can negatively influence physical activity levels. We aim to evaluate the clinical- and cost-effectiveness of integrating physiotherapist-delivered pain science education (PSE), an evidence-based conceptual change intervention targeting unhelpful pain beliefs by increasing pain knowledge, with an individualised walking, strengthening, and general education program.

Methods

Two-arm, parallel-design, multicentre randomised controlled trial involving 198 people aged ≥50 years with painful knee OA who do not meet physical activity guideline recommendations or walk regularly for exercise. Both groups receive an individualised physiotherapist-led walking, strengthening, and OA/activity education program via 4x weekly in-person treatment sessions, followed by 4 weeks of at-home activities (weekly check-in via telehealth), with follow-up sessions at 3 months (telehealth) and 5 and 9 months (in-person). The EPIPHA-KNEE group also receives contemporary PSE about OA/pain and activity, embedded into all aspects of the intervention. Outcomes are assessed at baseline, 12 weeks, 6 and 12 months. Primary outcomes are physical activity level (step count; wrist-based accelerometry) and self-reported knee symptoms (WOMAC Total score) at 12 months. Secondary outcomes are quality of life, pain intensity, global rating of change, self-efficacy, pain catastrophising, depression, anxiety, stress, fear of movement, knee awareness, OA/activity conceptualisation, and self-regulated learning ability. Additional measures include adherence, adverse events, blinding success, COVID-19 impact on activity, intention to exercise, treatment expectancy/perceived credibility, implicit movement/environmental bias, implicit motor imagery, two-point discrimination, and pain sensitivity to activity. Cost-utility analysis of the EPIPHA-KNEE intervention will be undertaken, in addition to evaluation of cost-effectiveness in the context of primary trial outcomes.

Discussion

We will determine whether the integration of PSE into an individualised OA education, walking, and strengthening program is more effective than receiving the individualised program alone. Findings will inform the development and implementation of future delivery of PSE as part of best practice for people with knee OA.

Trial registration

Australian New Zealand Clinical Trials Registry: ACTRN12620001041943 (13/10/2020).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04561-6.

Cytokines and Chemokines Involved in Osteoarthritis Pathogenesis

Osteoarthritis is a common cause of disability worldwide. Although commonly referred to as a disease of the joint cartilage, osteoarthritis affects all joint tissues equally. The pathogenesis of this degenerative process is not completely understood; however, a low-grade inflammation leading to an imbalance between anabolic and katabolic processes is a well-established factor. The complex network of cytokines regulating these processes and cell communication has a central role in the development and progression of osteoarthritis. Concentrations of both proinflammatory and anti-inflammatory cytokines were found to be altered depending on the osteoarthritis stage and activity. In this review, we analyzed individual cytokines involved in the immune processes with an emphasis on their function in osteoarthritis.

Randomized, Placebo-Controlled Analysis of the Knee Synovial Environment Following Platelet-Rich Plasma Treatment for Knee Osteoarthritis

BACKGROUND

Platelet-rich-plasma (PRP) is used to treat knee osteoarthritis; however, mechanistic evidence of PRP effectiveness for pain relief is limited.

OBJECTIVE

To assess molecular biomarkers and mesenchymal stem cells (MSCs) in synovial fluid during PRP treatment of the osteoarthritic knee joint.

DESIGN

Single blinded, randomized, placebo controlled pilot study.

SETTING

Veterans Affairs Medical Center.

PARTICIPANTS

Seventeen participants with mild to moderate knee osteoarthritis were randomized in a 2:1 placebo-controlled ratio, receiving PRP or saline (placebo) intra-articular injection into the knee joint.

METHODS

Knee synovial fluid was analyzed before the respective injections and again 10 days following injection. Participants were followed up to 12 months completing visual analog scale (VAS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaires at intervals over that period.

MAIN OUTCOME MEASURES

The effects of PRP on synovial protein and MSC gene expression levels were measured by multiplex enzyme-linked immunosorbent assay and quantitative polymerase chain reaction.

RESULTS

Novel biomarkers including levels of interleukin (IL)-5, IL-6, IL-10, and tumor necrosis factor-α were measured in synovial fluid 10 days after PRP treatment. Altered gene expression profiles in MSCs from patients treated with PRP were observed for matrix metalloproteinases and inflammatory markers (IL-6, IL-8, CCL2, TNF-α). A2M protease was significantly increased following PRP treatment (P = .005). WOMAC scores declined for up to 3 months from baseline levels and remained low at 6 and 12 months in the PRP group. In contrast, WOMAC scores for patients receiving the saline injection were relatively unchanged for up to 12 months.

CONCLUSIONS

We report significant changes for the biomarker A2M (P = .005) as well as differences in expression of cellular markers and postulate that PRP modulates the local knee synovial environment by altering the inflammatory milieu, matrix degradation, and angiogenic growth factors. The PRP treatment group had less pain and stiffness and improved function scores.

Does moderate intensity impact exercise and non-impact exercise induce acute changes in collagen biochemical markers related to osteoarthritis? - An exploratory randomized cross-over trial

OBJECTIVE

To investigate acute changes in biochemical markers of cartilage turnover in response to moderate intensity exercise with and without joint impact in humans with knee osteoarthritis.

DESIGN

We conducted a randomized, cross-over, exploratory clinical study. Twenty subjects with knee osteoarthritis (OA) were randomized, of which twenty completed 30 min of cycling and 15 completed 30 min of running on days 1 week apart. Fasting blood samples were taken before, immediately after and 1, 2, 3, and 24 h after activity was initiated. Midstream spot urine was sampled before and after activity. Serum samples were analyzed for concentrations of fragment of type II collagen degradation, C2M, fragment of type VI collagen degradation, C6M, cartilage oligomeric matrix protein, COMP, marker of type II collagen formation, PRO-C2, and urine for marker of crosslinked type II collagen degradation, CTX-II. To establish a reference, all subjects had similar samples taken during rest on a separate day. Data was analyzed in a restricted maximum likelihood based random effects linear mixed model.

RESULTS

C2M trended to increase after cycling compared running (13.49%, 95%CI: -0.36-27.34%) and resting (12.88%, 95%CI: 0.2-25.6%) and the type II collagen formation/degradation ratio switched towards degradation after cycling, but not running. C6M trended to decrease after cycling (-8.1%, 95%CI: -14.8 to -1.4%) and running (-6.8%, 95%CI: -14.16-0.55%).

CONCLUSION

In persons with knee OA moderate intensity exercise without joint impact may induce acute changes in circulating levels of biochemical markers reflecting type II and VI collagen degradation.

Complex Exercise Improves Anti-Inflammatory and Anabolic Effects in Osteoarthritis-Induced Sarcopenia in Elderly Women

We investigated the effects of a 15-week complex exercise program on osteoarthritis and sarcopenia by analyzing anabolic effects and the impact on the activities of daily living (ADLs). Nineteen women aged ≥60 years with sarcopenia (SEG, n = 9) or diagnosed with osteoarthritis with sarcopenia (OSEG, n = 10) were enrolled and underwent an exercise program. Insulin-like growth factor 1 (IGF-1), irisin, myostatin, interleukin-10 (IL-10), and tumor necrosis factor alpha (TNF-a) levels were analyzed pre- and post-intervention. Thigh cross-sectional area (TCSA) was measured pre- and post-intervention via computed tomography. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Short Physical Performance Battery (SPBB) were assessed pre- and post-interventions to assess ADL. There was a significant interaction effect between SEG and OSEG at the IGF-1 level post-intervention. Irisin increased and myostatin decreased post-intervention in both groups. IL-10 increased and TNF-α decreased post-intervention with a significant interaction effect in the OSEG group. TCSAs increased post-intervention in both groups. There was a significant interaction between the two groups. OSEG showed a greater WOMAC decrease and SPPB increase post-intervention, and there was a significant interaction effect. Combined exercise may be effective in improving biochemical factors, anabolic effects, and ADL in elderly women with osteoarthritis and sarcopenia.

Oral supplementation with fish cartilage hydrolysate accelerates joint function recovery in rat model of traumatic knee osteoarthritis

The objective of this study was to evaluate the effects of oral fish cartilage hydrolysate (FCH) on symptoms and joint tissue structure in rat developing osteoarthritis induced surgically. Osteoarthritis was induced in the right knee of mature male Lewis rats (n = 12/group) by surgical transection of the anterior cruciate ligament (ACLT) combined with partial medial meniscectomy (pMMx). Two weeks after surgery, rats were treated orally with either control (sterile H2O) or FCH for four weeks. Pain and function were assessed by dynamic weight-bearing test (incapacitance test), electronic Von Frey (EVF; hindpaw allodynia threshold), and pressure algometer (knee allodynia threshold). Time and groups differences at each time point were evaluated using a mixed model. The histological features were evaluated eight weeks after surgery using OARSI score. Mann-Whitney test nonparametric test was applied to compare OARSI score. ACTL/pMMx surgery significantly reduced weight-bearing and increased allodynia and sensitivity thresholds of the operated paw/knee. Globally, FCH improved these parameters faster, but no significant difference between control and FCH groups was observed. Eight weeks after surgery, rats developed moderate OA lesions. Compared with control, FCH did not significantly modify OA lesion severity assessed using the OARSI score. In this mechanically induced OA model, 4 weeks of supplementation with FCH had no significant effect on cartilage lesion, but tends to accelerate pain relief and joint function recovery. This positive trend may have opened the way for further investigation of FCH as potential treatment of joint discomfort associated with OA.

Role of Physical Exercise and Nutraceuticals in Modulating Molecular Pathways of Osteoarthritis

Osteoarthritis (OA) is a painful and disabling disease that affects millions of patients. Its etiology is largely unknown, but it is most likely multifactorial. OA pathogenesis involves the catabolism of the cartilage extracellular matrix and is supported by inflammatory and oxidative signaling pathways and marked epigenetic changes. To delay OA progression, a wide range of exercise programs and naturally derived compounds have been suggested. This literature review aims to analyze the main signaling pathways and the evidence about the synergistic effects of these two interventions to counter OA. The converging nutrigenomic and physiogenomic intervention could slow down and reduce the complex pathological features of OA. This review provides a comprehensive picture of a possible signaling approach for targeting OA molecular pathways, initiation, and progression.

Strength training in addition to neuromuscular exercise and education in individuals with knee osteoarthritis-the effects on pain and sensitization

BACKGROUND

There is a lack of evidence of the relative effects of different exercise modes on pain sensitization and pain intensity in individuals with knee osteoarthritis (KOA).

METHODS

Ninety individuals with radiographic and symptomatic KOA, ineligible for knee replacement surgery, were randomized to 12 weeks of twice-weekly strength training in addition to neuromuscular exercise and education (ST+NEMEX-EDU) or neuromuscular exercise and education alone (NEMEX-EDU). Outcomes were bilateral, lower-leg, cuff pressure pain- and tolerance thresholds (PPT, PTT), temporal summation (TS), conditioned pain modulation (CPM), self-reported knee pain intensity and number of painful body sites.

RESULTS

After 12 weeks of exercise, we found significant differences in increases in PPT (-5.01 kPa (-8.29 to -1.73, p = .0028)) and PTT (-8.02 kPa (-12.22 to -3.82, p = .0002)) in the KOA leg in favour of ST+NEMEX-EDU. We found no difference in effects between groups on TS, CPM or number of painful body sites. In contrast, there were significantly greater pain-relieving effects on VAS mean knee pain during the last week (-8.4 mm (-16.2 to -0.5, p = .0364) and during function (-16.0 mm (-24.8 to -7.3, p = .0004)) in favour of NEMEX-EDU after 12 weeks of exercise.

CONCLUSION

Additional strength training reduced pain sensitization compared to neuromuscular exercise and education alone, but also attenuated the reduction in pain intensity compared to neuromuscular exercise and education alone. The study provides the first dose- and type-specific insight into the effects of a sustained exercise period on pain sensitization in KOA. Future studies are needed to elucidate the role of different exercise modes.

SIGNIFICANCE

This study is an important step towards better understanding the effects of exercise in pain management of chronic musculoskeletal conditions. We found that strength training in addition to neuromuscular exercise and education compared with neuromuscular exercise and education only had a differential impact on pain sensitization and pain intensity, but also that regardless of the exercise mode, the positive effects on pain sensitization and pain intensity were comparable to the effects of other therapeutic interventions for individuals with knee osteoarthritis.

Expression of mitochondrial TSPO and FAM173B is associated with inflammation and symptoms in patients with painful knee osteoarthritis

Objectives

To characterize the expression profiles of two nuclear-encoded mitochondrial genes previously associated with chronic pain, the translocator protein (TSPO) and family with sequence similarity 173B (FAM173B), in different knee compartments from patients with painful knee OA. Also, to examine their association with the joint expression of inflammatory cytokines/chemokines and clinical symptoms.

Methods

The study was performed on 40 knee OA patients and 19 postmortem (PM) controls from which we collected the knee tissues: articular cartilage (AC), synovial membrane (SM) and subchondral bone (SB). Quantitative real-time polymerase chain reaction was used to determine the relative mRNA levels of TSPO, FAM173B, and inflammatory mediators IL6, IL8, IL10, IL12, MCP1, CCL11 and CCL17. OA patients rated their pain intensity (visual analogue scale), severity of knee-related outcomes (KOOS) and pain sensitivity assessed by pressure algometry.

Results

The gene expression of TSPO in SM was elevated in OA patients compared with control subjects while there were no group differences in AC and SB. Expression of FAM173B was reduced in SM but elevated in SB in OA patients compared with controls. The expression of TSPO and FAM173B in SM and SB was associated with the expression of inflammatory substances, but not in AC. Synovial expression of TSPO correlated with lower pain intensity and FAM173B with increased pressure pain sensitivity in OA.

Conclusion

Our results suggest that altered expression of TSPO and FAM173B is associated with joint expression of inflammatory mediators and with clinical symptoms indicating the relevance for the pathophysiology of knee OA.

Cytokines and Water Distribution in Anorexia Nervosa

In patients with anorexia nervosa (AN), decreased intracellular (ICW), extracellular (ECW), and total body water (TBW) as well as changes in serum cytokine concentrations have been reported. In this exploratory study, we measured body composition and serum cytokine levels in patients with AN (n = 27) and healthy controls (HCs; n = 13). Eating disorder symptom severity was assessed using the Eating Disorder Examination-Questionnaire (EDE-Q). Body composition was determined by bioimpedance analysis (BIA) which provided information on ICW, ECW, and TBW. Following blood collection, 27 cytokines and chemokines were quantified using multiplex ELISA-based technology: Eotaxin, Eotaxin-3, granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon- (IFN-) γ, interleukin- (IL-) 1α, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12/IL-23p40, IL-12p70, IL-13, IL-15, IL-16, IL-17A, interferon γ-induced protein- (IP-) 10, macrophage inflammatory protein- (MIP-) 1α, MIP-1β, monocyte chemoattractant protein- (MCP-) 1, MCP-4, thymus and activation-regulated chemokine (TARC), TNF-α, and TNF-β. ICW, ECW, and TBW volumes were significantly lower in patients with AN than in HCs. In the whole sample, GM-CSF, MCP-4, and IL-4 were positively, whereas IFN-γ, IL-6, and IL-10 were negatively associated with all three parameters of body water. In AN participants, we found a statistically significant negative correlation of IL-10 with ICW, ECW, and TBW. Our results suggest an interaction between body water and the cytokine system. Underlying mechanisms are unclear but may involve a loss of water from the gut, kidneys, or skin due to AN-associated inflammatory processes.

Adipose tissue is a critical regulator of osteoarthritis

Osteoarthritis (OA), the leading cause of pain and disability worldwide, disproportionally affects individuals with obesity. The mechanisms by which obesity leads to the onset and progression of OA are unclear due to the complex interactions among the metabolic, biomechanical, and inflammatory factors that accompany increased adiposity. We used a murine preclinical model of lipodystrophy (LD) to examine the direct contribution of adipose tissue to OA. Knee joints of LD mice were protected from spontaneous or posttraumatic OA, on either a chow or high-fat diet, despite similar body weight and the presence of systemic inflammation. These findings indicate that adipose tissue itself plays a critical role in the pathophysiology of OA. Susceptibility to posttraumatic OA was reintroduced into LD mice using implantation of a small adipose tissue depot derived from wild-type animals or mouse embryonic fibroblasts that undergo spontaneous adipogenesis, implicating paracrine signaling from fat, rather than body weight, as a mediator of joint degeneration.

The effect of exercise therapy on inflammatory activity assessed by MRI in knee osteoarthritis: Secondary outcomes from a randomized controlled trial

OBJECTIVE

This study investigated the effect of exercise therapy on inflammatory activity in synovitis and bone marrow lesions (BMLs) assessed by magnetic resonance imaging (MRI) in patients with knee OA.

METHODS

60 patients with knee OA were randomized 1:1 to 12 weeks of supervised exercise therapy 3 times/week (ET) or a no-attention control group (CG). Synovitis and BMLs were assessed with static MRI with and without contrast and with dynamic contrast enhanced MRI (DCE-MRI). DCE-MRI data was quantified using pixel-by-pixel methodology based on analysis of signal intensity curves. Pain was assessed by the Knee Injury and Osteoarthritis Outcome Score (KOOS). Analyses of covariance were used assessing group differences in changes from baseline to week 12.

RESULTS

33 patients adhered to the protocol and had valid MRI and KOOS data (ET, n = 16, CG, n = 17). Statistically significant and clinically relevant group difference in favour of ET was seen in KOOS pain change (-11.7 points, 95%CI: -20.1 to -3.4). There were statistically significant group differences in DCE-MRI assessed synovitis in the anterior synovium with unchanged inflammatory activity in the ET group compared to the CG. There were no group differences in BMLs and static MRI.

CONCLUSION

Inflammatory activity was unchanged, and pain was reduced in patients with knee OA adhering to 12 weeks of exercise therapy compared to a no-attention control group. The reduction in pain was not explained by changes in inflammatory activity. Overall, the results suggest that exercise is not harmful in knee OA. ClinicalTrials.gov number: NCT01545258.

Exercise as an Adjuvant to Cartilage Regeneration Therapy

This article provides a brief review of the pathophysiology of osteoarthritis and the ontogeny of chondrocytes and details how physical exercise improves the health of osteoarthritic joints and enhances the potential of autologous chondrocyte implants, matrix-induced autologous chondrocyte implants, and mesenchymal stem cell implants for the successful treatment of damaged articular cartilage and subchondral bone. In response to exercise, articular chondrocytes increase their production of glycosaminoglycans, bone morphogenic proteins, and anti-inflammatory cytokines and decrease their production of proinflammatory cytokines and matrix-degrading metalloproteinases. These changes are associated with improvements in cartilage organization and reductions in cartilage degeneration. Studies in humans indicate that exercise enhances joint recruitment of bone marrow-derived mesenchymal stem cells and upregulates their expression of osteogenic and chondrogenic genes, osteogenic microRNAs, and osteogenic growth factors. Rodent experiments demonstrate that exercise enhances the osteogenic potential of bone marrow-derived mesenchymal stem cells while diminishing their adipogenic potential, and that exercise done after stem cell implantation may benefit stem cell transplant viability. Physical exercise also exerts a beneficial effect on the skeletal system by decreasing immune cell production of osteoclastogenic cytokines interleukin-1β, tumor necrosis factor-α, and interferon-γ, while increasing their production of antiosteoclastogenic cytokines interleukin-10 and transforming growth factor-β. In conclusion, physical exercise done both by bone marrow-derived mesenchymal stem cell donors and recipients and by autologous chondrocyte donor recipients may improve the outcome of osteochondral regeneration therapy and improve skeletal health by downregulating osteoclastogenic cytokine production and upregulating antiosteoclastogenic cytokine production by circulating immune cells.

Inflammatory cytokines in horses with cervical articular process joint osteoarthritis on standing cone beam computed tomography

BACKGROUND

Standing cone beam computed tomography (CT) provides cross-sectional imaging of the caudal cervical articular process joints (CAPJs) in the sedated horse, though the clinical implications of osteoarthritis (OA) identified on CT in this location are unknown. Increases in concentrations of intra-synovial cytokines could lend support to the clinical significance of CAPJ OA identified on this imaging modality.

OBJECTIVES

Investigate the presence and concentration of intra-synovial inflammatory cytokines in CAPJs with and without standing cone beam CT evidence of OA using an equine specific multiplex assay.

STUDY DESIGN

Prospective clinical study.

METHODS

Standing cone beam CT of C5-6 and C6-7 was performed on horses with CAPJ OA and control horses. Synovial fluid samples of the CAPJs of C5-6 and C6-7 were obtained bilaterally using ultrasound guidance and analysed for concentrations of IFN-γ, IL-1β, IL-6, IL-10, IL-17 and TNFα with the Milliplex® multi-analyte profiling kit. CT Images were retrospectively graded using a novel grading scheme. Significant differences between concentrations of inflammatory cytokines between joints with different categories of osteoarthritis severity were explored using a Wilcoxon rank-sum test or Kruskal-Wallis test.

RESULTS

Concentrations of intra-synovial cytokines were higher in joints with moderate to severe OA when compared to joints with no or mild OA, with differences in concentrations of IL-17 reaching statistical significance (P = .007).

MAIN LIMITATIONS

Limitations include discrepancy in number, age, and breed between control and OA populations, use of a novel grading scheme, and lack of a histologic gold-standard to confirm the presence and severity of CAPJ OA.

CONCLUSIONS

Differences in inflammatory cytokines between caudal CAPJs with and without evidence of moderate to severe osteoarthritis on standing cone beam CT exist. This finding lends support to the clinical relevance of a diagnosis of moderate to severe CAPJ OA in the caudal cervical vertebral column as identified with this imaging modality.

Approaching sites of action of drugs in clinical pharmacology: New analytical options and their challenges

Clinical pharmacology is an important discipline for drug development aiming to define pharmacokinetics (PK), pharmacodynamics (PD) and optimum exposure to drugs, i.e. the concentration-response relationship and its modulators. For this purpose, information on drug concentrations at the anatomical, cellular and molecular sites of action is particularly valuable. In pharmacological assays, the limited accessibility of target cells in readily available samples (i.e. blood) often hampers mass spectrometry-based monitoring of the absolute quantity of a compound and the determination of its molecular action at the cellular level. Recently, new sample collection methods have been developed for the specific capture of rare circulating cells, especially for the diagnosis of circulating tumour cells. In parallel, new advances and developments in mass spectrometric instrumentation now allow analyses to be scaled down to the cellular level. Together, these developments may permit the monitoring of minute drug quantities and show their effect at the cellular level. In turn, such PK/PD associations on a cellular level would not only enrich our pharmacological knowledge of a given compound but also expand the basis for PK/PD simulations. In this review, we describe novel concepts supporting clinical pharmacology at the anatomical, cellular and molecular sites of action, and highlight the new challenges in mass spectrometry-based monitoring. Moreover, we present methods to tackle these challenges and define future needs.

Combined therapies with exercise, ozone and mesenchymal stem cells improve the expression of HIF1 and SOX9 in the cartilage tissue of rats with knee osteoarthritis

Purpose

Knee osteoarthritis (OA) is a common type of degenerative joint disease which decreases the quality of life. Sex-determining region Y box 9 (SOX9) and hypoxia-inducible factor-1 (HIF1) are considered as the key regulators of OA. We investigated the effect of combined therapies with mesenchymal stem cells (MSCs), ozone (O3) and exercise training on SOX9 and HIF1 expression in the cartilage of rats with knee OA.

Methods

Knee OA was induced by surgical method. OA rats were divided into model, MSCs, ozone, exercise, MSCs + ozone, MSCs + exercise, ozone + exercise and MSCs + ozone + exercise groups. Rats in the MSCs group received intraarticular injection of 1 × 106 cells/kg. Rats in the ozone group received O3 at the concentration of 20 μg/mL, once weekly for 3 weeks. Rats in the exercise group were trained on rodent treadmill three times per week. 48 hours after the programs, cartilage tissues were isolated and the expression of SOX9 and HIF1 was determined using Real-Time PCR.

Results

Significant differences were found in the expression of SOX9 and HIF1 between groups (P < 0.0001). Although combined therapies with exercise, MSCs and O3 significantly increased the expression of SOX9 and HIF1 in the cartilage tissue of rats with knee OA, combination of exercise with O3 was significantly more effective compared to the other combined therapies (P < 0.001).

Conclusions

Combined therapy with exercise, MSCs and O3 significantly increased the expression of SOX9 and HIF1 genes in the cartilage of rats with knee OA; however, exercise + O3 was significantly more effective.

ISOKINETIC RESPONSE, VISCOSUPPLEMENTATION AND STRENGTH TRAINING IN GONARTHROSIS

ABSTRACT Introduction Viscosupplementation and strength training are proposed interventions in the treatment of knee osteoarthritis. Objective To describe the isokinetic response in women with knee osteoarthritis who underwent both interventions. Methods A double-blind, randomized clinical trial involving thirty women diagnosed with grade II and III bilateral knee osteoarthritis using the radiological criteria of Kellgren & Lawrence. The subjects were randomized into three groups of ten patients each: one group was submitted to viscosupplementation and strength training (VST), another was submitted to strength training (ST) only, and a third to viscosupplementation (VS) only. All evaluations followed the study phases defined as pre-procedure (PRE); after 48 hours of VS (POS-VS); after 12 weeks of training (POS T); and after eight weeks of detraining (POS D). Intra-articular knee infiltrations were performed with a single dose of Hylan GF-20 and isokinetic dynamometry to determine the maximum torque in knee extension and flexion. Pain was measured by the visual analogue scale (VAS). Results The interventions promoted improvements in the isokinetic response in all three groups and in both muscle groups, with advantage for the extensor group. A significant difference was noticed in the isokinetic response of the trained groups when compared only to the viscosupplemented group (p<0.005), and the VST group showed better isokinetic response compared to the ST group. Conclusion Combined treatment with viscosupplementation and strength training, and treatment with strength training only, presented better results in terms of isokinetic response and pain reduction than viscosupplementation alone. Level of evidence I; Therapeutic studies-Investigating the results of treatment.

Insulin Resistance in Osteoarthritis: Similar Mechanisms to Type 2 Diabetes Mellitus

Osteoarthritis (OA) and type 2 diabetes mellitus (T2D) are two of the most widespread chronic diseases. OA and T2D have common epidemiologic traits, are considered heterogenic multifactorial pathologies that develop through the interaction of genetic and environmental factors, and have common risk factors. In addition, both of these diseases often manifest in a single patient. Despite differences in clinical manifestations, both diseases are characterized by disturbances in cellular metabolism and by an insulin-resistant state primarily associated with the production and utilization of energy. However, currently, the primary cause of OA development and progression is not clear. In addition, although OA is manifested as a joint disease, evidence has accumulated that it affects the whole body. As pathological insulin resistance is viewed as a driving force of T2D development, now, we present evidence that the molecular and cellular metabolic disturbances associated with OA are linked to an insulin-resistant state similar to T2D. Moreover, the alterations in cellular energy requirements associated with insulin resistance could affect many metabolic changes in the body that eventually result in pathology and could serve as a unified mechanism that also functions in many metabolic diseases. However, these issues have not been comprehensively described. Therefore, here, we discuss the basic molecular mechanisms underlying the pathological processes associated with the development of insulin resistance; the major inducers, regulators, and metabolic consequences of insulin resistance; and instruments for controlling insulin resistance as a new approach to therapy.