Systemic inflammation and painful joint burden in osteoarthritis: a matter of sex?

Nutritional Epigenomics: Bioactive Dietary Compounds in the Epigenetic Regulation of Osteoarthritis

Nutritional epigenomics is exceptionally important because it describes the complex interactions among food compounds and epigenome modifications. Phytonutrients or bioactive compounds, which are secondary metabolites of plants, can protect against osteoarthritis by suppressing the expression of inflammatory and catabolic mediators, modulating epigenetic changes in DNA methylation, and the histone or chromatin remodelling of key inflammatory genes and noncoding RNAs. The combination of natural epigenetic modulators is crucial because of their additive and synergistic effects, safety and therapeutic efficacy, and lower adverse effects than conventional pharmacology in the treatment of osteoarthritis. In this review, we have summarized the chondroprotective properties of bioactive compounds used for the management, treatment, or prevention of osteoarthritis in both human and animal studies. However, further research is needed into bioactive compounds used as epigenetic modulators in osteoarthritis, in order to determine their potential value for future clinical applications in osteoarthritic patients as well as their relation with the genomic and nutritional environment, in order to personalize food and nutrition together with disease prevention.

Crosstalk between bone and brain in Alzheimer's disease: Mechanisms, applications, and perspectives

Alzheimer's disease (AD) is a neurodegenerative disease that involves multiple systems in the body. Numerous recent studies have revealed bidirectional crosstalk between the brain and bone, but the interaction between bone and brain in AD remains unclear. In this review, we summarize human studies of the association between bone and brain and provide an overview of their interactions and the underlying mechanisms in AD. We review the effects of AD on bone from the aspects of AD pathogenic proteins, AD risk genes, neurohormones, neuropeptides, neurotransmitters, brain-derived extracellular vesicles (EVs), and the autonomic nervous system. Correspondingly, we elucidate the underlying mechanisms of the involvement of bone in the pathogenesis of AD, including bone-derived hormones, bone marrow-derived cells, bone-derived EVs, and inflammation. On the basis of the crosstalk between bone and the brain, we propose potential strategies for the management of AD with the hope of offering novel perspectives on its prevention and treatment. HIGHLIGHTS: The pathogenesis of AD, along with its consequent changes in the brain, may involve disturbing bone homeostasis. Degenerative bone disorders may influence the progression of AD through a series of pathophysiological mechanisms. Therefore, relevant bone intervention strategies may be beneficial for the comprehensive management of AD.

Osteoarthritis as a Systemic Disease Promoted Prostate Cancer In Vivo and In Vitro

Osteoarthritis (OA) is increasing worldwide, and previous work found that OA increases systemic cartilage oligomeric matrix protein (COMP), which has also been implicated in prostate cancer (PCa). As such, we sought to investigate whether OA augments PCa progression. Cellular proliferation and migration of RM1 murine PCa cells treated with interleukin (IL)-1α, COMP, IL-1α + COMP, or conditioned media from cartilage explants treated with IL-1α (representing OA media) and with inhibitors of COMP were assessed. A validated murine model was used for tumor growth and marker expression analysis. Both proliferation and migration were greater in PCa cells treated with OA media compared to controls (p < 0.001), which was not seen with direct application of the stimulants. Migration and proliferation were not negatively affected when OA media was mixed with downstream and COMP inhibitors compared to controls (p > 0.05 for all). Mice with OA developed tumors 100% of the time, whereas mice without OA only 83.4% (p = 0.478). Tumor weight correlated with OA severity (Pearson correlation = 0.813, p = 0.002). Moreover, tumors from mice with OA demonstrated increased Ki-67 expression compared to controls (mean 24.56% vs. 6.91%, p = 0.004) but no difference in CD31, PSMA, or COMP expression (p > 0.05). OA appears to promote prostate cancer in vitro and in vivo.

The impact of diabetes status on pain and physical function following total joint arthroplasty for hip and knee osteoarthritis: variation by sex and body mass index

Few studies have examined diabetes impact on total joint arthroplasty (TJA) outcomes, with variable findings. We investigated the association between diabetes and post-TJA physical function and pain, examining whether diabetes impact differs by sex and BMI. Patient sample completed questionnaires within 3 months prior to hip or knee TJA for osteoarthritis (OA) and 1-year post-surgery. Surgical 'non-response' was defined as < 30% improvement in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and physical function at 1-year. Two adjusted logistic regression models were estimated: (1) excluding, (2) including an interaction between diabetes, sex and BMI. The sample (626 hip, 754 knee) was 54.9% female, had mean BMI of 30.1, 13.0% reported diabetes. In adjusted models excluding an interaction, diabetes was not associated with non-response. However, a significant 3-way interaction (physical function: p = 0.003; pain: p = 0.006) between diabetes, sex, and BMI was found and was associated with non-response: non-response probability increased with increasing BMI in men with diabetes, but decreased with increasing BMI in women in diabetes. Findings suggest uncertainty in diabetes impact may be due to differential impacts by sex and BMI. A simple consideration of diabetes as present vs. absent may not be sufficient, with implications for the large TJA population.

Metabolic syndrome increases osteoarthritis risk: findings from the UK Biobank prospective cohort study

OBJECTIVE

The association between Metabolic Syndrome (MetS), its components, and the risk of osteoarthritis (OA) has been a topic of conflicting evidence in different studies. The aim of this present study is to investigate the association between MetS, its components, and the risk of OA using data from the UK Biobank.

METHODS

A prospective cohort study was conducted in the UK Biobank to assess the risk of osteoarthritis (OA) related to MetS. MetS was defined according to the criteria set by the International Diabetes Federation (IDF). Additionally, lifestyle factors, medications, and the inflammatory marker C-reactive protein (CRP) were included in the model. Cox proportional hazards regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI). The cumulative risk of OA was analyzed using Kaplan-Meier curves and log-rank tests. To explore potential nonlinear associations between MetS components and OA risk, a restricted cubic splines (RCS) model was employed. In addition, the polygenic risk score (PRS) of OA was calculated to characterize individual genetic risk.

RESULTS

A total of 45,581 cases of OA were identified among 370,311 participants, with a median follow-up time of 12.48 years. The study found that individuals with MetS had a 15% higher risk of developing OA (HR = 1.15, 95%CI:1.12-1.19). Additionally, central obesity was associated with a 58% increased risk of OA (HR = 1.58, 95%CI:1.5-1.66), while hyperglycemia was linked to a 13% higher risk (HR = 1.13, 95%CI:1.1-1.15). Dyslipidemia, specifically in triglycerides (HR = 1.07, 95%CI:1.05-1.09) and high-density lipoprotein (HR = 1.05, 95%CI:1.02-1.07), was also found to be slightly associated with OA risk. When stratified by PRS, those in the high PRS group had a significantly higher risk of OA compared to those with a low PRS, whereas no interaction was found between MetS and PRS on OA risks. Furthermore, the presence of MetS significantly increased the risk of OA by up to 35% in individuals with elevated CRP levels (HR = 1.35, 95% CI:1.3-1.4).

CONCLUSION

MetS and its components have been found to be associated with an increased risk of OA, particularly in individuals with elevated levels of CRP. These findings highlight the significance of managing MetS as a preventive and intervention measure for OA.

Frequency of multisite non-hand joint involvement in patients with thumb-base osteoarthritis, and associations with functional and patient-reported outcomes

Purpose

In OA studies, the focus often is on an index-joint; other affected joint sites are often overlooked. In this thumb-base OA study, we documented the frequency of symptomatic non-hand joint sites and investigated whether their count was associated with thumb-specific functional and patient-reported outcome measures.

Design

Patients seeking care for thumb-base OA (conservative or surgical) were included. A patient-completed questionnaire captured sociodemographic and health characteristics, symptomatic hand and non-hand joint sites, and outcome measures (thumb-base pain intensity, symptoms and disability (TASD) and upper-extremity disability/symptoms (quickDASH)). Grip and pinch strength were measured. Linear regressions examined the association between each outcome and symptomatic joint site count, adjusted for several covariates.

Results

The mean age of the 145 patients was 62 years, 72% were female. Mean symptomatic non-hand joint site count was 3.6. Ten percent reported only their hands as symptomatic; 30% reported 2-3 other symptomatic sites, and 49% reported 4+. From cross-sectional multivariable analyses, a higher symptomatic non-hand joint site count was associated with worse scores for all patient-reported outcomes and grip strength. Every unit increase in joint site count (49% had a 4+ count) was associated with a 2.1-3.3 unit increase (worse) in patient-reported outcome scores (all p ​< ​0.02).

Conclusions

In this sample, nearly 80% of patients had 2+ symptomatic non-hand joint sites. These symptoms were associated with worse thumb- and hand-specific outcomes, suggesting a need for awareness of whole body OA burden, with implications for outcome score interpretations, study designs, and provision of care in thumb-base OA.

A Brief Overview: Sex Differences in Prevalent Chronic Musculoskeletal Conditions

Musculoskeletal (MSK) pain disorders are some of the most prevalent and disabling chronic pain conditions worldwide. These chronic conditions have a considerable impact on the quality of life of individuals, families, communities, and healthcare systems. Unfortunately, the burden of MSK pain disorders does not fall equally across the sexes. Females consistently demonstrate more prevalent and severe clinical presentations of MSK disorders, and this disparity increases in magnitude with age. The aim of the present article is to review recent studies that have examined sex differences between males and females in four of the most common MSK pain disorders: neck pain, low back pain, osteoarthritis, and rheumatoid arthritis.

High serum levels of galectins 1 and 4 in osteoarthritis patients

BACKGROUND

Although immunostaining of galectins is associated with cartilage damage, the serum levels of these lectins in osteoarthritis (OA) are not fully understood.

OBJECTIVE

Therefore, we evaluate the concentrations of galectins-1, 3, 4, and 7 in patients with osteoarthritis and correlate them with clinical parameters.

METHODS

This cross-sectional study involved 60 osteoarthritis patients and 43 healthy volunteers, who had serum samples collected for galectins titration by Enzyme-Linked Immunosorbent Assay (ELISA).

RESULTS

Our finds showed that the median values of gal-1 and 4 serum levels in patients were statistically higher (13,990 and 969.1 pg/mL, respectively) than in healthy controls (1,798 and 519.5 pg/mL) with p < 0.001. Further, gal-1 expressed higher levels in patients who had joint edema at the time of collection with a median value of 14,970 pg/mL.

CONCLUSION

Surprisingly, galectin-4 appears to be involved in the osteoarthritis inflammation process as the well-known galectin-1.

The influence of inflammation on cardiovascular disease in women

The onset of cardiovascular disease in women is almost a decade later than men, partly due to the protective effect of estrogen prior to menopause. Recently, it was noted that while there have been advances in improving the morbidity and mortality from CVD in women older than 55 years, the improvement in younger women has been stagnant. The mechanism behind this lag is unclear. This manuscript reviews the literature available on the sex-specific inflammatory response in the context of traditional and non-traditional cardiovascular disease risk factors. Our review suggests that women have a differential inflammatory response to various disease states that increases their risk for CVD and warrants a distinct prioritization from men when calculating cardiovascular disease risk.

Innate Immunity at the Core of Sex Differences in Osteoarthritic Pain?

Osteoarthritis (OA) is a progressive whole-joint disease; no disease-modifying drugs are currently available to stop or slow its process. Symptoms alleviation is the only treatment option. OA is the major cause of chronic pain in adults, with pain being the main symptom driving patients to seek medical help. OA pathophysiology is closely associated with the innate immune system, which is also closely linked to pain mediators leading to joint pain. Pain research has shown sex differences in the biology of pain, including sexually dimorphic responses from key cell types in the innate immune system. Not only is OA more prevalent in women than in men, but women patients also show worse OA outcomes, partially due to experiencing more pain symptoms despite having similar levels of structural damage. The cause of sex differences in OA and OA pain is poorly understood. This review provides an overview of the involvement of innate immunity in OA pain in joints and in the dorsal root ganglion. We summarize the emerging evidence of sex differences regarding innate immunity in OA pain. Our main goal with this review was to provide a scientific foundation for future research leading to alternative pain relief therapies targeting innate immunity that consider sex differences. This will ultimately lead to a more effective treatment of pain in both women and men.

Linking physical activity with clinical, functional, and structural outcomes: an evidence map using the Osteoarthritis Initiative

Physical activity is consistently recommended across clinical practice guidelines for managing knee osteoarthritis, yet prescription rates are low. Evidence mapping uses a systematic approach to visually illustrate and summarize published evidence, highlight gaps in the literature, and formulate research questions. The purpose of this study was to review and summarize evidence published from the Osteoarthritis Initiative (OAI) linking physical activity with clinical, functional, and structural knee osteoarthritis outcomes. Electronic databases were searched until June 2021. Studies from the OAI reporting subjective (Physical Activity Scale for the Elderly, PASE) or objective (accelerometry) physical activity data were included. Scatter plots were created to represent each outcome group (clinical, functional, structural) and physical activity measure (PASE, accelerometry) to map the evidence by the directional effect (positive, interaction, negative, or no effect) associated with physical activity. Forty-two articles were included in this review. Physical activity was quantified using PASE (n = 21), accelerometry (n = 20), or both (n = 1). Studies reported consistently positive physical activity effects on clinical (n = 22) and functional (n = 20) outcomes, with few exceptions. Structural (n = 15) outcomes were largely reported as interaction effects by physical activity intensity or sex, or as no significant effect. A network of interconnected outcomes emerged, with clinical and functional outcomes often reported together, and structural outcomes reported individually. This study provides an overview of current evidence linking physical activity to multiple interrelated knee osteoarthritis outcomes using an OAI-driven model. These evidence maps can be used as a framework to guide future investigations of the effects of physical activity on knee osteoarthritis.

An Exploration of Blood Marker×Environment Interaction Effects on Pain Severity and Interference Scores in People With Acute Musculoskeletal Trauma

OBJECTIVES

Explore the moderating effects of psychological or social variables on associations between biomarkers of inflammation/stress and clinical reports of pain.

METHODS

This is a cross-sectional exploratory study. Data were drawn from the Systematic Merging of Biology, Mental Health and Environment (SYMBIOME) longitudinal study (clinicaltrials.gov ID no. NCT02711085). Eligible participants were adults who presented to an Urgent Care Centre in Ontario, Canada within 3 weeks of a noncatastrophic musculoskeletal trauma (no surgery or hospitalization). A questionnaire package was given that included the Brief Pain Inventory (capturing pain severity and pain interference) and relevant person-level variables. Blood samples were also drawn for serum analysis of 8 target biomarkers (brain-derived neurotrophic factor, transforming growth factor beta 1 [TGF-β1], c-reactive protein, tumor necrosis factor-α, interleukin [IL]-1β, IL-6, IL-10, and cortisol).

RESULTS

Employment before trauma (employed for pay/not employed for pay) fully moderated the association between tumor necrosis factor-α and pain severity (∆R2=4.4%). Pre-existing psychopathology (yes/no) fully moderated the association between TGF-β1 and pain severity (∆R2=8.0%). Sex (male/female) fully moderated the association between c-reactive protein and pain severity (∆R2=6.3%). A pre-existing pain condition (yes/no) was significantly associated with worse pain interference (R2=7.2%), and partially moderated the effect of IL-1β on pain interference (∆R2=6.9%). Higher peritraumatic life stress significantly explained 8.9% of variance in pain interference alone, and partially moderated the effect of TGF-β1 on interference (∆R2=4.4%).

DISCUSSION

Simple bivariate associations between blood-based markers and clinical symptoms are unlikely to reveal meaningful relationships. However, when stratified by existing person-level or "metadata" variables, an association may exist for at least 1 clinically relevant subgroup.

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.

How to Differentiate Gout, Calcium Pyrophosphate Deposition Disease, and Osteoarthritis Using Just Four Clinical Parameters

Clinical differentiation between gout, osteoarthritis (OA), and calcium pyrophosphate deposition disease (CPPD) remains a hurdle in daily practice without imaging or arthrocentesis. We performed a retrospective analysis of consecutive patients with gout, CPPD, and OA at a tertiary rheumatology center. A total of 277 patients were enrolled, with 164 suffering from gout, 76 from CPPD, and 37 from OA. We used ANOVA and conditional inference tree analysis (Ctrees) to find associations between clinical, laboratory, and imaging data and gout, OA, and CPPD. The sonographic double contour sign was unable to differentiate gout from CPPD. Ctrees were able to exclude OA and CPPD as possible differentials based on elevated uric acid, C-reactive protein (CRP), presence of arterial hypertension, and sex, diagnosing gout with a sensitivity and specificity of 95.1% and 41.6%, respectively. Elevated CRP was observed using simple linear regressions in patients with type II diabetes, higher cumulative joint scores, increased number of affected joints, as well as elevated uric acid, erythrocyte sedimentation rate, and leukocyte count. Ctrees were able to differentiate gout, OA, and CPPD based on just four characteristics. Inflammatory response correlated with type II diabetes, more or larger joint involvement, and elevated uric acid levels.

An Evidence-Based Systematic Review of Human Knee Post-Traumatic Osteoarthritis (PTOA): Timeline of Clinical Presentation and Disease Markers, Comparison of Knee Joint PTOA Models and Early Disease Implications

Understanding the causality of the post-traumatic osteoarthritis (PTOA) disease process of the knee joint is important for diagnosing early disease and developing new and effective preventions or treatments. The aim of this review was to provide detailed clinical data on inflammatory and other biomarkers obtained from patients after acute knee trauma in order to (i) present a timeline of events that occur in the acute, subacute, and chronic post-traumatic phases and in PTOA, and (ii) to identify key factors present in the synovial fluid, serum/plasma and urine, leading to PTOA of the knee in 23-50% of individuals who had acute knee trauma. In this context, we additionally discuss methods of simulating knee trauma and inflammation in in vivo, ex vivo articular cartilage explant and in vitro chondrocyte models, and answer whether these models are representative of the clinical inflammatory stages following knee trauma. Moreover, we compare the pro-inflammatory cytokine concentrations used in such models and demonstrate that, compared to concentrations in the synovial fluid after knee trauma, they are exceedingly high. We then used the Bradford Hill Framework to present evidence that TNF-α and IL-6 cytokines are causal factors, while IL-1β and IL-17 are credible factors in inducing knee PTOA disease progresssion. Lastly, we discuss beneficial infrastructure for future studies to dissect the role of local vs. systemic inflammation in PTOA progression with an emphasis on early disease.

The gut microbiome-joint connection: implications in osteoarthritis

Supplemental Digital Content is available in the text

Osteoarthritis is a debilitating disease leading to joint degeneration, inflammation, pain, and disability. Despite efforts to develop a disease modifying treatment, the only accepted and available clinical approaches involve palliation. Although many factors contribute to the development of osteoarthritis, the gut microbiome has recently emerged as an important pathogenic factor in osteoarthritis initiation and progression. This review examines the literature to date regarding the link between the gut microbiome and osteoarthritis.

The impact of multijoint symptoms on patient-reported disability following surgery for lumbar spine osteoarthritis

BACKGROUND CONTEXT

In the lumbar spine osteoarthritis (LS-OA) population having surgery for lumbar spinal stenosis (LSS) symptoms, a significant proportion of patients experience limited benefit following the intervention. Thus, identifying contributing factors to this is important. Individuals with OA often have multiple joint symptoms, yet this has received limited attention in this population.

PURPOSE

Document the occurrence of joint symptoms among patients undergoing surgery for LS-OA, and investigate the influence of these symptoms on disability postsurgery.

DESIGN

Prospective study of consecutive patients followed to 12-month postsurgery.

PATIENT SAMPLE

Patients undergoing surgery (decompression surgery, with or without fusion) for neurogenic claudication with or without back pain due to LSS with a primary pathology diagnosis of LS-OA.

OUTCOMES MEASURES

Patient self-reported: Oswestry Disability Index (ODI), completed pre- and 12-month postsurgery; and, completed presurgery, age, sex, education, smoking, comorbid conditions, opioid use, short/long-term disability, depression and anxiety symptoms, back and leg pain intensity, presence of spondylolisthesis, procedure, prior spine surgery, and joints with arthritis and "pain/stiffness/swelling most days of the month" indicated on a homunculus (a joint site count was derived).

ASSESSMENTS

Height and weight, used to calculate body mass index; timed-up-and-go performance-based test.

METHODS

Outcome of interest was achieving a clinically important improvement (CII) in ODI by 12-month postsurgery (yes/no). The association between joint site count and achieving a CII was examined by multivariable logistic regression analyses, adjusted for other measures.

RESULTS

In all, 165 patients were included. The mean age was 67 years (range: 44-90) and 47% were female. Seventy-seven percent reported 1+ joint site other than the back, 62% reported 2+, and 25% reported 4+. Among those achieving a CII, 21% had 4+ joint sites, compared with 31% among those not achieving a CII. Adjusted analyses: Increasing joint site count was associated with increasing risk (odds ratio [OR]: 1.32, 95% confidence interval [CI]: 1.05, 1.66) of not achieving a CII; for those with 4+ joints, adjusted probability of not achieving a CII exceeded 50%. Also associated with an increased risk of not achieving a CII was presurgery anxiety (OR: 2.97, 95% CI: 1.02, 8.65), opioid use (OR: 2.89, 95% CI: 1.07, 7.82), and worse back pain intensity score (OR: 1.27, 95% CI: 1.05, 1.53).

CONCLUSIONS

Multijoint involvement was highly prevalent in this LS-OA surgical sample. Its association with poorer postsurgery outcome supports a comprehensive approach to OA management and care. Knowledge of multijoint symptoms should inform patient education, shared decision-making, and recommendations for postsurgical rehabilitation and self-management strategies.

IL-17 and immunologically induced senescence regulate response to injury in osteoarthritis

Senescent cells (SnCs) are implicated in the pathogenesis of age-related diseases including osteoarthritis (OA), in part via expression of a senescence-associated secretory phenotype (SASP) that includes immunologically relevant factors and cytokines. In a model of posttraumatic OA (PTOA), anterior cruciate ligament transection (ACLT) induced a type 17 immune response in the articular compartment and draining inguinal lymph nodes (LNs) that paralleled expression of the senescence marker p16INK4a (Cdkn2a) and p21 (Cdkn1a). Innate lymphoid cells, γδ+ T cells, and CD4+ T cells contributed to IL-17 expression. Intra-articular injection of IL-17-neutralizing antibody reduced joint degeneration and decreased expression of the senescence marker Cdkn1a. Local and systemic senolysis was required to attenuate tissue damage in aged animals and was associated with decreased IL-17 and increased IL-4 expression in the articular joint and draining LNs. In vitro, we found that Th17 cells induced senescence in fibroblasts and that SnCs skewed naive T cells toward Th17 or Th1, depending on the presence of TGF-β. The SASP profile of the inflammation-induced SnCs included altered Wnt signaling, tissue remodeling, and cell-cycle pathways not previously implicated in senescence. These findings provide molecular targets and mechanisms for senescence induction and therapeutic strategies to support tissue healing in an aged environment.

Discordance between self-reported and performance-based function among knee osteoarthritis surgical patients: Variations by sex and obesity

Background

There is currently no standardized method for measuring functional status in knee osteoarthritis (OA) patients, despite that it is one of the top priorities when determining eligibility for total knee arthroplasty (TKA). The purpose of the current investigation was to identify factors associated with discordance between individual self-report and performance-based measures of function for obese and non-obese men and women with knee OA.

Methods

In a cohort of 727 knee OA patients scheduled for TKA, physical function prior to surgery was assessed with the self-reported physical function subscale of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC-pf), and the performance-based Timed Up and Go (TUG). Data on sociodemographic characteristics, health status, knee pain intensity, symptomatic joint site count, and pain catastrophizing were collected via questionnaire. The primary outcome was the difference in rescaled score between a participant’s self-report and performance-based measures of function. Multivariable linear regression stratified by sex and obesity status was used to identify factors associated with discordance.

Results

The mean age of participants was 65.5 years and 55% were women. With younger age, self-reported scores indicated increasingly worse function compared to performance-based scores, regardless of sex or obesity status. Among non-obese individuals, greater knee pain intensity was associated with a participant’s self-report score indicating increasingly worse function compared to their performance-based score. For obese women, pain catastrophizing, and number of symptomatic joints were also associated with discordance as was reporting fewer comorbidities.

Conclusions

Physical function may be differentially represented by self-reported and performance-based measures depending on a variety of patient factors. Our findings add to the evidence which suggests both measures should be used when assessing functional status prior to TKA.

Association of Visceral Adiposity With Pain but Not Structural Osteoarthritis

OBJECTIVE

Osteoarthritis (OA) and pain are both made more severe by low-grade inflammation. This study was undertaken to examine whether visceral fat, a major source of inflammatory cytokines and adipokines, is associated with an increased risk of knee OA or musculoskeletal pain.

METHODS

Subjects in the Multicenter Osteoarthritis Study cohort, who were age 50-79 years and had or were at high risk of knee OA, underwent whole-body dual x-ray absorptiometry (DXA) at baseline. At baseline, 30 months, and 60 months radiographs and magnetic resonance images (MRIs) of the knees were obtained, and patients were asked to score the severity of their knee pain and to identify sites of joint pain using a body homunculus. Baseline DXA scans were used to measure total body fat and visceral and subcutaneous fat in the torso. The association of fat depot size with structural outcomes (incident radiographic OA and cartilage loss and synovitis on MRI) and with pain outcomes (worsening knee pain, number of painful joints, and widespread pain) was assessed. Regression analyses were adjusted for age, sex, race, education level, smoking status, physical activity, body mass index (BMI), and depressive symptoms.

RESULTS

Of the 2,961 participants at baseline, 60.7% were women. The mean age was 62.5 years and mean BMI was 30.5 kg/m² . After adjustment for covariates, no fat measures were associated with any structural outcomes. However, total and visceral, but not subcutaneous, fat were positively associated with worsening knee pain (P = 0.0005 for total fat and P = 0.007 for visceral fat) and widespread pain (P = 0.001 for total fat and P = 0.02 for visceral fat), and the amount of visceral fat was associated with the number of painful joints (P = 0.07).

CONCLUSION

Our findings indicate that visceral fat is associated with an increased risk of musculoskeletal and widespread pain.

Risk Factor Profiles for Individuals With Diagnosed OA and With Symptoms Indicative of OA: Findings From the Canadian Longitudinal Study on Aging

OBJECTIVE

The vast majority of published estimates of osteoarthritis (OA) burden are based on an OA diagnosis. These data are limited, as individuals often do not visit a physician until their symptoms are moderate to severe. This study compared individuals with an OA diagnosis to those with OA joint symptoms but without a diagnosis considering a number of sociodemographic and health characteristics. A further distinction was made between individuals with symptoms in one joint site and those with symptoms in multiple joint sites.

METHODS

Data are from 23 186 respondents aged 45 to 85 years from the first cycle of the Canadian Longitudinal Study on Aging. A multinomial logistic regression model examined the relationship between sociodemographic- and health-related characteristics and OA status (diagnosed OA, joint symptoms without OA, no OA or joint symptoms). In addition, logistic regression models assessed the relationship between OA status and usually experiencing pain and having some degree of functional limitation.

RESULTS

Twenty-one percent of respondents reported a diagnosis of OA, and 25% reported symptoms typical of OA but without an OA diagnosis. Other than being slightly younger, the characteristic profile of individuals with symptoms in two or more joint sites was indistinguishable from that of those with diagnosed OA.

CONCLUSION

It may be warranted to consider OA-like multiple joint symptoms when deriving estimates of OA-attributed population health and cost burden.

Dietary Patterns and Progression of Knee Osteoarthritis: Data from the Osteoarthritis Initiative

BACKGROUND

While some individual foods and nutrients have been associated with knee osteoarthritis (KOA) progression, the association between dietary patterns and KOA progression has received little research attention.

OBJECTIVE

The objective of this study was to determine whether dietary patterns, derived by principal components analysis (PCA), are associated with KOA progression.

METHODS

In the Osteoarthritis Initiative (OAI), a prospective cohort with clinical centers in Maryland, Ohio, Pennsylvania, and Rhode Island, 2757 participants with existing KOA (mean age 62 y) and diet assessed at baseline were followed for ≤72 mo. Using PCA, Western and prudent dietary patterns were derived. Radiographic KOA progression was assessed using 2 separate measures, 1 full Kellgren-Lawrence (KL) grade increase and loss in joint space width (JSW). Symptomatic KOA progression was defined as an increase in or remaining in 1 of the 2 highest classification categories of the Western Ontario and McMaster Universities Arthritis Index (WOMAC).

RESULTS

Adherence to Western and prudent dietary patterns was significantly associated with radiographic and symptomatic progression of KOA. With increasing Western pattern score, there was increased KL-worsening risk (compared with quartile 1, HR for quartile 4: 1.30; 95% CI: 1.05, 1.61; P-trend < 0.01) and increased odds of progression to higher WOMAC score (compared with quartile 1, OR for quartile 4: 1.39; 95% CI: 1.18, 1.63; P-trend < 0.01) but no significant change in JSW loss. With increasing prudent pattern score there was decreased KL-worsening risk (compared with quartile 1, HR for quartile 4: 0.79; 95% CI: 0.64, 0.98; P-trend = 0.02), decreased JSW loss (quartile 1: 0.46 mm; quartile 4: 0.38 mm; P-trend < 0.01), and decreased odds of higher WOMAC progression (compared with quartile 1, OR for quartile 4 0.73; 95% CI: 0.62, 0.86; P-trend < 0.01) in multivariable adjusted models.

CONCLUSIONS

Adherence to a Western dietary pattern was associated with increased radiographic and symptomatic KOA progression, while following a prudent pattern was associated with reduced progression. In general, for people already diagnosed with KOA, eating a diet rich in fruits, vegetables, fish, whole grains, and legumes may be related to decreased radiographic and symptomatic disease progression.

Osteoarthritis year in review 2018: biomarkers (biochemical markers)

OBJECTIVE

The aim of this narrative review is to summarize important findings from biochemical marker studies relevant to osteoarthritis (OA) in the context of new discoveries and clinical and scientific need.

DESIGN

We conducted a systematic search of electronic medical databases (Embase, Medline, Web of Science, Cochrane central) between 01-03-2017 and 31-03-2018. The search was restricted to human studies, English language and full text available publications while reviews were excluded. Only papers describing protein based biomarkers measured in human body fluids (blood, urine and synovial fluid (SF)) were included. Of the 992 papers, 86 were reviewed here, with inclusion primarily based on relevance to OA biochemical markers.

RESULTS

This review highlights a selection of studies based on their quality and perceived importance to the field mainly including those that¹ evaluate prognostic value of biomarkers for OA progression (i.e., biomarkers reflecting change in composition of joint tissues and biomarkers of inflammation)², help in assessment of intervention efficacy, and³ are innovative and uncover new candidate biomarkers, or use new approaches in biomarker discovery.

CONCLUSIONS

Key findings and implications for possible clinical utility of biochemical markers are summarized and discussed. Given the paucity of robust biomarkers within the field, and the heterogeneity of the condition, enormous works are needed for development and validation of novel and clinically applicable biomarkers to reduce the impact of this highly prevalent and debilitating condition.

Resveratrol Supplementation Reduces Pain and Inflammation in Knee Osteoarthritis Patients Treated with Meloxicam: A Randomized Placebo-Controlled Study

Resveratrol, a polyphenolic compound, is a powerful antioxidant with remarkable anti-inflammatory properties. Inflammation and pain plays an important role in the pathogenesis of knee osteoarthritis (OA) and could cause tissue damage and morbidity. The aim of this study was to evaluate the anti-inflammatory and pain reduction activities of orally administered resveratrol in patients with knee OA. We carried out a 90-day pilot study to evaluate the ability of orally administered resveratrol, as an adjuvant with meloxicam, to decrease knee joint pain and biomarkers of inflammation in comparison with a placebo. One hundred ten men and women (45-75 years old) diagnosed with mild to moderate knee OA were treated with 15 mg per day meloxicam and either 500 mg per day resveratrol or placebo for 90 days in a double-blind, randomized control trial. Pain severity was evaluated at the beginning and at the end of treatment using Visual Analogue Scale-100 scores. Fasting blood was collected to determine serum interleukins 1β and 6, tumor necrosis factor-α, C-reactive protein, and complement proteins C3 and C4. The resveratrol-treated group experienced a time-dependent significant decrease in pain severity (P < .001). Serum levels of the biochemical markers were significantly reduced compared with the placebo-treated group (P < .01). These findings suggest that resveratrol may be an effective "add-on" option with meloxicam in the treatment of patients with mild to moderate knee OA.

Neuropathic pain in end-stage hip and knee osteoarthritis: differential associations with patient-reported pain at rest and pain on activity

OBJECTIVE

We investigated whether pain at rest and pain on activity were differentially associated with neuropathic pain scores in individuals with end-stage hip and knee OA.

DESIGN

Study participants were 843 patients with hip or knee OA scheduled for total joint arthroplasty. In pre-surgery questionnaires, measures of socio-demographics, health status, medication use, neuropathic pain (painDETECT), pain at rest and pain on activity (WOMAC pain items), depression (HADS) and pain catastrophizing (PCS) were collected. Multivariable linear regression models were estimated for men and women separately to examine the association between neuropathic pain scores (outcome) and study measures, entered in blocks.

RESULTS

Sample mean age was 65.1 years (SD: 9.6); 57.1% were women. Mean painDETECT scores were significantly higher (P ≤ֹ 0.001) for women (11.2 ± 6.6 out of 38) than men (9.3 ± 7.0), with 35.6% of women and 27.7% of men meeting cut-offs for possible or likely neuropathic pain. In the final regression model for women, the coefficients for both types of pain were statistically significant, although the coefficient for pain at rest was 1.6 times greater than that for pain on activity. For men, only pain at rest was significantly associated with neuropathic pain scores.

CONCLUSIONS

Findings support that possible neuropathic pain is experienced by a notable proportion of patients with end-stage hip and knee OA and is more strongly associated with pain at rest than pain on activity, particularly in men. Clinical presentation of pain at rest may warrant more thorough evaluation for potential neuropathic pain and have implications for appropriate pain management.

Osteoarthritis biomarkers: year in review

OBJECTIVE

To summarise important findings from biomarker studies relevant to osteoarthritis (OA), published between April 2016 and March 2017; to consider these findings in the context of new discoveries and technologies, and clinical and scientific need in OA.

DESIGN

Studies were selected by PubMed search, conducted between 01/04/2016 and 01/03/2017. MeSH terms [biomarker] AND [OA] were used; the search was restricted to Human, English language and Full Text Available publications, which yielded 50 eligible publications. Any biomarker was considered, including non-proteins and other clinical measurements.

RESULTS

Three main areas are overviewed: 1) Studies examining highly validated biomarkers, in the FNIH OA Biomarkers Consortium and elsewhere, particularly their ongoing application and validation. Control reference intervals, work on predictive validity and other longitudinal studies examining prognostic value of biomarkers in large cohorts are reviewed. 2) Novel studies relating to biomarkers of inflammation are discussed, including complement, the performance of markers of so-called 'cold inflammation' and results from clinical trials including biomarkers. 3) Discovery studies, including whole blood RNA, proteomics and metabolomics are reviewed, with an emphasis on new technologies.

CONCLUSIONS

Discovery, characterisation and qualification of various biomarkers is ongoing; several novel protein and non-protein candidate biomarkers have been reported this year. Biomarkers provide us with an opportunity to better diagnose and stratify the disease, via established panels or new discovery approaches. Improving quality of sampling and testing, and measuring large numbers of markers simultaneously in large cohorts would seem likely to identify new clinically applicable biomarkers, which are still much needed in this disease.

An Autologous Anti-Inflammatory Protein Solution Yielded a Favorable Safety Profile and Significant Pain Relief in an Open-Label Pilot Study of Patients with Osteoarthritis

Osteoarthritis (OA) is a progressive and degenerative disease, which may result in significant pain and decreased quality of life. Recent updates in our understanding of OA have demonstrated that it is a whole joint disease that has many similarities to an unhealed wound containing inflammatory cytokines. The nSTRIDE Autologous Protein Solution (APS) Kit is a medical device under development for the treatment of OA. The APS Kit processes a patient's own blood at the point of care to contain high concentrations of anti-inflammatory cytokines and anabolic growth factors. This study assessed the safety and treatment effects of a single intra-articular injection of APS. Eleven patients were enrolled in this study. Sufficient blood could not be drawn from one patient who was subsequently withdrawn, leaving 10 patients treated. Minor adverse events (AEs) were experienced by seven subjects (63.6%). There was one serious AE (diverticulitis) unrelated to the device or procedure. One subject experienced AEs that were judged “likely” to be procedure related (arthralgia/musculoskeletal discomfort) and all resolved within 6 days of injection. All other AEs were unrelated to the device or procedure. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain scores improved significantly over time (ANOVA, p < 0.0001, 12.0 ± 1.2 preinjection, 3.3 ± 2.9 one year postinjection, and 72.5% WOMAC pain improvement). There was significant positive correlation between white blood cell concentration in APS and improvement in WOMAC pain scores.

Anti-inflammatory effect as a mechanism of effectiveness underlying the clinical benefits of pelotherapy in osteoarthritis patients: regulation of the altered inflammatory and stress feedback response

The purpose of the present investigation was to evaluate whether an anti-inflammatory effect together with an improvement of the regulation of the interaction between the inflammatory and stress responses underlies the clinical benefits of pelotherapy in osteoarthritis (OA) patients. This study evaluated the effects of a 10-day cycle of pelotherapy at the spa centre 'El Raposo' (Spain) in a group of 21 OA patients diagnosed with primary knee OA. Clinical assessments included pain intensity using a visual analog scale; pain, stiffness and physical function using the Western Ontario and McMaster Universities Arthritis Index; and health-related quality of life using the EuroQol-5D questionnaire. Serum inflammatory cytokine levels (IL-1β, TNF-α, IL-8, IL-6, IL-10 and TGF-β) were evaluated using the Bio-Plex® Luminex® system. Circulating neuroendocrine-stress biomarkers, such as cortisol and extracellular 72 kDa heat shock protein (eHsp72), were measured by ELISA. After the cycle of mud therapy, OA patients improved the knee flexion angle and OA-related pain, stiffness and physical function, and they reported a better health-related quality of life. Serum concentrations of IL-1β, TNF-α, IL-8, IL-6 and TGF-β, as well as eHsp72, were markedly decreased. Besides, systemic levels of cortisol increased significantly. These results confirm that the clinical benefits of mud therapy may well be mediated, at least in part, by its systemic anti-inflammatory effects and neuroendocrine-immune regulation in OA patients. Thus, mud therapy could be an effective alternative treatment in the management of OA.

Strawberries Improve Pain and Inflammation in Obese Adults with Radiographic Evidence of Knee Osteoarthritis

Osteoarthritis (OA), the most common form of arthritis, is a significant public health burden in U.S. adults. Among its many risk factors, obesity is a key player, causing inflammation, pain, impaired joint function, and reduced quality of life. Dietary polyphenols and other bioactive compounds in berries, curcumin, and tea have shown effects in ameliorating pain and inflammation in OA, but few clinical studies have been reported. The purpose of the present study was to examine the effects of dietary strawberries on pain, markers of inflammation, and quality of life indicators in obese adults with OA of the knee. In a randomized, double-blind cross-over trial, adults with radiographic evidence of knee OA (n = 17; body mass index (BMI): (mean ± SD) 39.1 ± 1.5; age (years): 57 ± 7) were randomized to a reconstituted freeze-dried strawberry beverage (50 g/day) or control beverage daily, each for 12 weeks, separated by a 2-week washout phase (total duration, 26 weeks). Blood draws and assessments of pain and quality of life indicators were conducted using the Visual Analog Scale for Pain (VAS Pain), Measures of Intermittent and Constant Osteoarthritis Pain (ICOAP), and Health Assessment Questionnaire-Disability Index (HAQ-DI) questionnaires, which were completed at baseline and at weeks 12, 14, and 26 of the study. Among the serum biomarkers of inflammation and cartilage degradation, interleukin (IL)-6, IL-1β, and matrix metalloproteinase (MMP)-3 were significantly decreased after strawberry vs. control treatment (all p < 0.05). Strawberry supplementation also significantly reduced constant, intermittent, and total pain as evaluated by the ICOAP questionnaire as well as the HAQ-DI scores (all p < 0.05). No effects of treatment were noted on serum C-reactive protein (CRP), nitrite, glucose, and lipid profiles. Dietary strawberries may have significant analgesic and anti-inflammatory effects in obese adults with established knee OA.