The longitudinal relationship between hand, hip and knee osteoarthritis and cardiovascular events: a population-based cohort study

Osteoarthritis and hypertension: observational and Mendelian randomization analyses

BACKGROUND

The association between osteoarthritis (OA) and hypertension is a subject of ongoing debate in observational research, and the underlying causal relationship between them remains elusive.

METHODS

This study retrospectively included 24,871 participants in the National Health and Nutrition Examination Survey (NHANES) from 2013 to 2020. Weighted logistic regression was performed to investigate the connection between OA and hypertension. Additionally, Mendelian randomization (MR) analysis was conducted to explore the potential causal relationship between OA and hypertension.

RESULTS

In the NHANES data, after adjusting for multiple confounding factors, there was no significant relationship between OA and hypertension (OR 1.30, 95% CI, 0.97-1.73, P = 0.089). However, among males, OA appeared to be associated with a higher risk of hypertension (OR 2.25, 95% CI, 1.17-4.32, P = 0.019). Furthermore, MR results indicate no relationship between multiple OA phenotypes and hypertension: knee OA (IVW, OR 1.024, 95% CI: 0.931-1.126, P = 0.626), hip OA (IVW, OR 0.990, 95% CI: 0.941-1.042, P = 0.704), knee or hip OA (IVW, OR 1.005, 95% CI: 0.915-1.105, P = 0.911), and OA from UK Biobank (IVW, OR 0.796, 95% CI: 0.233-2.714, P = 0.715). Importantly, these findings remained consistent across different genders and in reverse MR.

CONCLUSIONS

Our study found that OA patients had a higher risk of hypertension only among males in the observational study. However, MR analysis did not uncover any causal relationship between OA and hypertension.

Arterial Stiffness, Assessed Using the Cardio-Ankle Vascular Index, before and 2 Years after Total Knee Arthroplasty in Patients with Knee Osteoarthritis

Purpose: Cardiovascular disease (CVD) is a major risk factor for mortality in patients with osteoarthritis, and such comorbidities increase the risk of postoperative complications following total knee arthroplasty (TKA). Arteriosclerosis plays a major role in hemodynamic dysfunction and CVD; however, the postoperative changes in arteriosclerosis following TKA have not been evaluated. Therefore, we assessed the postoperative changes in arteriosclerosis using the cardio-ankle vascular index (CAVI) in patients undergoing TKA, and its relationships with preoperative patient characteristics. Methods: Arteriosclerosis was prospectively evaluated in 119 consecutive patients (140 knees) (15 males (17), 104 females (123); median age 73 years) with knee osteoarthritis who underwent TKA. CAVI was measured before and 2 years after TKA, and the relationships between CAVI and preoperative age, sex, BMI, physical activity status, comorbidities, clinical score, triglyceride concentration, cholesterol concentration, and smoking history were analyzed. Results: CAVI remained stable or improved in 54 joints (39%) and worsened in 86 joints (61%) 2 years post-operation. The median difference between pre- and postoperative CAVI was 0.2 (-0.3, 0.8), and the only preoperative factor associated with this change was preoperative CAVI (r = -0.469, p < 0.001). No other preoperative factor had a significant effect on postoperative arteriosclerosis. Conclusions: The results suggest that patients who undergo TKA subsequently show less severe arteriosclerosis, and the protective effect of TKA on arterial stiffness is greater in those with a higher preoperative CAVI. TKA may be an effective means of reducing the deterioration of arteriosclerosis associated with knee osteoarthritis, at least in the relatively short term.

Hip and Knee Osteoarthritis, Not Nonsteroidal Anti-Inflammatory Drugs, are Linked to Cardiac Disease

BACKGROUND

In 2005, the Food and Drug Administration placed a black-box warning (the most stringent warning for drugs) on all nonaspirin nonsteroidal anti-inflammatory drugs (NSAIDs) stating that these agents may cause heart attacks and/or strokes. No level I evidence demonstrates that nonselective NSAIDs increase cardiovascular risk. An alternative hypothesis is that hip and knee osteoarthritis (OA) indirectly causes cardiovascular disease (CVD) through decreased activity and NSAIDs are correlated with CVD as an arthritis treatment.

METHODS

Systematic reviews were conducted to find observational studies evaluating the association of hip and/or knee OA, CVD, activity, walking, and step counts. The systematic review found studies correlating hip and/or knee OA and CVD morbidity incidence (n = 2); CVD morbidity prevalence (n = 6); odds ratios, relative risks, or hazard ratios of CVD morbidity (n = 11); relative risk, standardized mortality ratios, or hazard ratios of CVD mortality (n = 14); and all-cause mortality hazard ratios associated with NSAID use (n = 3).

RESULTS

Hip OA (5 studies), knee OA (9 studies), and hip and knee OA (6 studies) are linked to an increased risk of CVD morbidity and mortality. Cardiac risk increases with validated disability scores, use of walking aids, walking difficulties, longer follow-up times, younger ages of OA onset, numbers of joints involved, and OA severities. No study linked NSAID use to cardiac disease.

CONCLUSIONS

All studies with more than 10-year follow-up linked cardiac disease with hip and knee OA. No study linked nonselective NSAID use to CVD. The Food and Drug Administration should reconsider the black-box warnings on naproxen, ibuprofen, and celecoxib.

Characteristics of Preoperative Arteriosclerosis Evaluated by Cardio-Ankle Vascular Index in Patients with Osteoarthritis before Total Knee Arthroplasty

PURPOSE

Cardiovascular disease (CVD) is a major risk factor for mortality in patients with osteoarthritis, and comorbidities increase postoperative complications after total knee arthroplasty (TKA). Arteriosclerosis plays a main role in hemodynamic dysfunction and CVD; however, arteriosclerosis has not been preoperatively evaluated before TKA using the cardio-ankle vascular index (CAVI). In this study, we evaluated the degree of preoperative arteriosclerosis using the CAVI in patients undergoing TKA, as well as its correlations with several preoperative patient factors.

METHODS

Arteriosclerosis was evaluated in 209 consecutive patients (251 knees) with osteoarthritis who underwent TKA at our institution between May 2011 and June 2022. The CAVI was measured in the supine position 1 day before TKA, and the correlations between the CAVI and several clinical factors were analyzed.

RESULTS

The CAVI was normal in 62 knees (25%), borderline in 71 knees (28%), and abnormal in 118 knees (47%). Univariate analysis revealed a moderate positive correlation between preoperative CAVI and age (r = 0.451, p < 0.001) and a weak negative correlation between preoperative CAVI and body weight (r = -0.306, p < 0.001) and body mass index (BMI) (r = -0.319, p < 0.001). Multivariate analysis showed that age (β = 0.349, p < 0.001) and BMI (β = -0.235, p < 0.001) were significantly correlated with preoperative CAVI.

CONCLUSION

Arteriosclerosis should be carefully managed intraoperatively and postoperatively in patients with osteoarthritis undergoing TKA, particularly in older patients and patients with a low BMI.

Chronic Pain-Associated Cardiovascular Disease: The Role of Sympathetic Nerve Activity

Chronic pain affects many people world-wide, and this number is continuously increasing. There is a clear link between chronic pain and the development of cardiovascular disease through activation of the sympathetic nervous system. The purpose of this review is to provide evidence from the literature that highlights the direct relationship between sympathetic nervous system dysfunction and chronic pain. We hypothesize that maladaptive changes within a common neural network regulating the sympathetic nervous system and pain perception contribute to sympathetic overactivation and cardiovascular disease in the setting of chronic pain. We review clinical evidence and highlight the basic neurocircuitry linking the sympathetic and nociceptive networks and the overlap between the neural networks controlling the two.

Improving diagnosis and treatment of knee osteoarthritis in persons with type 2 diabetes: development of a complex intervention

BACKGROUND

Symptomatic knee osteoarthritis (OA) commonly co-occurs in people with type 2 diabetes (T2DM) and increases the risk for diabetes complications, yet uptake of evidence-based treatment is low. We combined theory, stakeholder involvement and existing evidence to develop a multifaceted intervention to improve OA care in persons with T2DM. This was done in partnership with Arthritis Society Canada to leverage the existing infrastructure and provincial funding for community arthritis care.

METHODS

Each step was informed by a User Advisory Panel of stakeholder representatives, including persons with lived experience. First, we identified the target groups and behaviours through consulting stakeholders and current literature. Second, we interviewed persons living with T2DM and knee OA (n = 18), health professionals (HPs) who treat people with T2DM (n = 18) and arthritis therapists (ATs, n = 18) to identify the determinants of seeking and engaging in OA care (patients), assessing and treating OA (HPs) and considering T2DM in OA treatment (ATs), using the Theoretical Domains Framework (TDF). We mapped the content to behavioural change techniques (BCTs) to identify the potential intervention components. Third, we conducted stakeholder meetings to ascertain the acceptability and feasibility of intervention components, including content and modes of delivery. Fourth, we selected intervention components informed by prior steps and constructed a programme theory to inform the implementation of the intervention and its evaluation.

RESULTS

We identified the barriers and enablers to target behaviours across a number of TDF domains. All stakeholders identified insufficient access to resources to support OA care in people with T2DM. Core intervention components, incorporating a range of BCTs at the patient, HP and AT level, sought to identify persons with knee OA within T2DM care and refer to Arthritis Society Canada for delivery of evidence-based longitudinal OA management. Diverse stakeholder input throughout development allowed the co-creation of an intervention that appears feasible and acceptable to target users.

CONCLUSIONS

We integrated theory, evidence and stakeholder involvement to develop a multifaceted intervention to increase the identification of knee OA in persons with T2DM within diabetes care and improve the uptake and engagement in evidence-based OA management. Our partnership with Arthritis Society Canada supports future spread, scalability and sustainability. We will formally assess the intervention feasibility in a randomized pilot trial.

Association between knee osteoarthritis and the risk of cardiovascular disease and the synergistic adverse effects of lack of exercise

We aimed to determine whether knee OA is associated with CVD risk and all-cause death and to evaluate whether the association differs by exercise behavior. We used Korea National Health Insurance Service (KNHIS) database and included 201,466 participants (7572 subjects diagnosed with knee OA) who underwent health screening between 2009 and 2015. Those who had been diagnosed with knee OA or CVD before the index year were excluded. Cox proportional hazard models were used after adjusting for sociodemographic and CVD risk factors to evaluate the association between knee OA and CVD risk and all-cause death. Stratification analysis was further performed to determine the effect of exercise behavior on this relationship. During a median follow-up of 7.06 ± 2.24 years, 8743 CVD (2510 MI and 6553 stroke) cases developed. Individuals with knee OA had increased risks of CVD [hazard ratio (HR) 1.26, 95% confidence interval (CI) 1.15-1.38], myocardial infarction (MI) (HR 1.20, 95% CI 1.00-1.44), and stroke (HR 1.29, 95% CI 1.16-1.43) compared with those without knee OA. Those with knee OA who did not exercise had an increased risk of CVD (HR 1.25, 95% CI 1.11-1.40), whereas no significant increased CVD risk was observed in those with knee OA who exercised at least once a week (HR 1.11, 95% CI 0.96-1.28). There was no association between knee osteoarthritis and all-cause death. Knee OA was independently associated with an increased risk of CVD. Lack of exercise might have a synergistic adverse effect on the association between knee OA and CVD.

Factors associated with social participation and community ambulation in people with osteoarthritis: Findings from the Canadian Longitudinal Study on Aging

AIM

Walking in the community allows participation in meaningful activities which positively influences self-rated health and quality of life. Our objective was to identify factors associated with social participation and community ambulation in a representative sample of Canadian adults with osteoarthritis (OA).

METHODS

Data were from >3800 participants in the Baseline Tracking Dataset of the Canadian Longitudinal Study on Aging with OA of the hip and/or knee. Outcomes included frequency of participation in 8 community-based activities (past year, social participation), and frequency walking outside the home (past 7 days, community ambulation). Explanatory variables (15 for social participation, 11 for community ambulation) established in previous literature were evaluated. Variables significant in univariate binary logistic regression models were entered into multivariable models.

RESULTS

Frequency of social participation was greater for females, and individuals with higher levels of education. Those who were younger, dissatisfied with life, and had difficulty walking 2-3 blocks were less likely to participate. Having fewer chronic conditions, being younger, being single/widowed and being interviewed in spring/summer were associated with more frequent ambulation. Lower self-rated health, difficulty walking 2-3 blocks, pain and being female were associated with less frequent walking outside the home.

CONCLUSION

Many factors influence frequency of social participation and community ambulation. The ability to walk short distances is positively associated with both outcomes. This important factor can and should be addressed clinically to improve health and quality of life in people with OA.

The Regional Burden and Disability-Adjusted Life Years of Knee Osteoarthritis in Kazakhstan 2014-2020

A Global Burden of Disease (GBD) study reported that 9.6 million years lived with disability (YLDs) were lost due to hip and knee osteoarthritis (KOA) in 2017. Although the GBD study presents the disease burden at the global level, there is no information on any Central Asian country. This study aims to investigate the epidemiology of knee osteoarthritis in Kazakhstan. The data of 56,895 people with KOA between 2014-2020 was derived from the Unified National Electronic Health System of Kazakhstan and retrospectively analyzed. The majority of the cohort (76%) were women, of Kazakh ethnicity (66%), and older than 50 years of age (87%). The risk of gonarthrosis escalated for women after 50 years and peaked at 75 years with a rate of 3062 females admitted to hospital per 100,000 women in the population. This observation is approximately three times higher than for men of the same age group. A geographical analysis showed that the Jambyl oblast, West Kazakhstan, North Kazakhstan, and the Akmola oblast have the highest burden of disease. During the observation period, 127,077 age-adjusted YLDs were lost due to knee osteoarthritis. This is the first study in Kazakhstan to investigate the burden of knee osteoarthritis. This research recognizes age and sex-based differences, and regional disparities in the incidence of knee osteoarthritis. This knowledge can lead to the development of more specific diagnostic approaches and gender-personalized therapy protocols for patients.

[Influence of chronic pain in osteoarthritis on the risk of cardiovascular diseases and modern methods of drug prevention]

The purpose of the review of scientific medical literature was to evaluate the data of the epidemiology of osteoarthritis (OA) and cardiovascular diseases (CVD) with the analysis of risk factors, pathophysiological and pathobiochemical mechanisms of the relationship between OA and the risk of developing CVD in the presence of chronic pain, modern strategies for screening and management of this cohort of patients, the mechanism of action and pharmacological effects of chondroitin sulfate (CS). Conclusions were drawn about the need for additional clinical and observational studies of the efficacy and safety of the parenteral form of CS (Chondroguard) in patients with chronic pain in OA and CVD, improvement of clinical recommendations for the treatment of chronic pain in patients with OA and cardiovascular risk, with special attention to interventions that eliminate mobility restrictions in patients and the inclusion of basic and adjuvant therapy with DMOADs to achieve the goals of multipurpose monotherapy in patients with contraindications to standard therapy drugs.

Gait-related self-efficacy is directly associated with daily step counts in individuals with knee osteoarthritis

BACKGROUND

In addition to physical factors, psychological factors such as self-efficacy (SE) reportedly affect physical activity (PA) levels in individuals with knee osteoarthritis (OA). However, the relationship between PA and SE for walking tasks in patients with knee OA remains unclear. The present study aimed to investigate the direct and indirect pathways of SE for walking tasks and the influence of previously reported factors on PA level in individuals with knee OA.

METHODS

A cross-sectional design was employed. Eighty-five individuals with knee OA were enrolled. The daily step count (Steps) was considered an objective level of PA. The SE for the walking task was assessed using a modified Gait Efficacy Scale (mGES). Data on gait speed (GS), the visual analog scale (VAS) score for knee pain, Kellgren-Lawrence (K-L) grade of radiographic severity of knee OA, age, and body mass index were collected. Path analysis was performed to investigate the direct and indirect effects of these variables on Steps.

RESULTS

After exclusion, 70 participants were included. The alternative model, which included Steps, mGES, GS, VAS, K-L grade, and age, showed a good fit. mGES and age had a direct effect on Steps (standardized path coefficients: 0.337 and -0.542, respectively), while the other variables had indirect effects.

CONCLUSIONS

The SE for walking tasks was directly associated with Steps representative of the PA level. This finding suggests that SE for the walking task may be important in improving PA levels in individuals with knee OA.

Hip and Knee Arthroplasty Outcomes for Nonagenarian Patients

INTRODUCTION

Studies have previously reported higher complication rates in elective total joint arthroplasty (TJA) for nonagenarians compared with younger cohorts. The purpose of this study was to assess whether nonagenarians were still at increased risk of complications and hospital readmissions by answering three questions: (1) Do nonagenarians have an increased risk of medical complications after TJA compared with octogenarians and septuagenarians? (2) Do nonagenarians have an increased risk of surgical complications after TJA compared with octogenarians and septuagenarians? (3) Do nonagenarians have an increased risk of hospital readmission after TJA compared with octogenarians and septuagenarians?

METHODS

A total of 174 patients undergoing primary TJA between 2010 and 2017 were included; 58 nonagenarians (older than 90 years) were matched with 58 octogenarians (age 80 to 84 years) and 58 septuagenarians (age 70 to 74). Groups were matched by sex, diagnosis, surgeon, surgical joint, and year of surgery. Within each group, 31 patients (53%) underwent total hip arthroplasty and 27 patients (47%) underwent total knee arthroplasty. Comorbidities, American Society of Anesthesiologists physical status scores, and Charlson Comorbidity Index scores were captured preoperatively. Complications and readmissions occurring within 90 days postoperatively were evaluated.

RESULTS

Nonagenarians had the highest rate of medical complications (33%) compared with octogenarians (14%) and septuagenarians (3%) (P < 0.001). Rates of surgical complications were not statistically different among nonagenarians (12%), octogenarians (9%), and septuagenarians (10%) (P = 0.830). Rates of hospital readmission were highest in nonagenarian patients (11%), but not statistically different compared with octogenarians (5%) or septuagenarians (2%) (P = 0.118).

CONCLUSION

Nonagenarians were 3.1 times more likely to have a complication after TJA. The incidence of medical complications was highest in nonagenarians compared with octogenarians and septuagenarians, but rates of orthopaedic complications were similar. Nonagenarians who elect to proceed with TJA should be informed that they have an increased risk of postoperative medical complications compared with younger patients undergoing the same operation.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

The association between short-term, chronic localized and chronic widespread pain and risk for cardiovascular disease in the UK Biobank

AIMS

The interplay between pain of different chronicity and cardiovascular disease (CVD) is incompletely understood. We aimed to investigate the association between different levels of chronic or nonchronic pain and risk of CVD.

METHODS AND RESULTS

Participants in the UK Biobank who reported pain at baseline were divided into three groups according to pain duration and widespreadness. Participants reporting no pain were controls. Multivariable Cox regression was used to investigate the association between pain and incidence of myocardial infarction, heart failure, stroke, cardiovascular mortality, and composite CVD (defined as any of the before-mentioned cardiovascular events). Of 475 171 participants, 189 289 reported no pain, 87 830 reported short-term pain, 191 716 chronic localized pain, and 6336 chronic widespread pain (CWP). During a median of 7.0 years' follow-up, participants with chronic localized pain and CWP had, after adjustment for age, sex, established cardiovascular risk factors, physical activity, anxiety, depression, cancer, chronic inflammatory/painful disease, pain/anti-inflammatory medication, socioeconomic status, a significantly increased risk for composite CVD [hazard ratio (HR) 1.14, confidence interval (CI) 1.08-1.21, P < 0.001; and HR 1.48, CI 1.28-1.73, P < 0.001, respectively] compared with controls, with similar results when using the different specific CVDs as outcomes. Population attributable risk proportion for chronic pain as a risk factor for composite CVD was comparable with that of diabetes (8.6 vs. 7.3%, respectively).

CONCLUSION

Chronic pain is associated with an increased risk for myocardial infarction, stroke, heart failure, and cardiovascular death independent of established cardiovascular risk factors, socioeconomic factors, comorbidities and medication. Our study, the largest to date, confirms and extends our understanding of chronic pain as an underestimated cardiovascular risk factor with important public health implications.

Development and Validation of a Novel Nomogram to Predict the Risk of Intervertebral Disc Degeneration

Intervertebral disc degeneration (IVDD) has been a complex disorder resulted from genetic and environmental risk factors. The aim of this study was to identify the risk factors associated with IVDD in orthopaedic patients and develop a prediction model for predicting the risk of IVDD. A total of 309 patients were retrospectively included in the study and randomly divided into the training group and the validation group. The least absolute shrinkage and selection operator regression (LASSO) and the univariate logistic regression analysis were used to optimize factors selection for the IVDD risk model. Multivariable logistic regression analysis was used to establish a predicting nomogram model incorporating the factors. In addition, discrimination, calibration, and clinical usefulness of the nomogram model were evaluated via the C-index, receiver operating characteristic (ROC) curve, calibration plot, and decision curve analysis (DCA). Then, based on the results above, the relationship between IVDD and angiotensin II (AngII) level in peripheral blood was examined prospectively. The predictors of the nomogram include age, sex, hypertension, diabetes, gout, working posture, and exercising hours per week. The C-index values of the training and validation groups were 0.916 (95% CI, 0.876-0.956) and 0.949 (95% CI, 0.909-0.989), respectively, which indicated that the model displayed good discrimination. In addition, the area under the curve (AUC) values of the ROC curve of the training and the validation group were 0.815 (95% CI, 0.759-0.870) and 0.805 (95% CI, 0.718-0.892), respectively, revealing the satisfactory discrimination performance of the model. The prospective investigation showed that the average AngII level in the degenerated group (97.62 ± 44.02 pg/mL) was significantly higher than that in the nondegenerated group (52.91 ± 9.01 pg/mL) (p < 0.001). This present study explored the risk factors for IVDD and established a prediction model, which would effectively predict the risk of IVDD. In addition, based on the prediction model, AngII was revealed to be a potentially auxiliary clinical diagnostic marker for IVDD.

Glucosamine Use Is Associated with a Higher Risk of Cardiovascular Diseases in Patients with Osteoarthritis: Results from a Large Study in 685,778 Subjects

Glucosamine is widely used around the world and as a popular dietary supplement and treatment in patients with osteoarthritis in China; however, the real-world cardiovascular risk of glucosamine in long-term use is still unclear. A retrospective, population-based cohort study was performed, based on the Beijing Medical Claim Data for Employees from 1 January 2010 to 31 December 2017. Patients newly diagnosed with osteoarthritis were selected and divided into glucosamine users and non- glucosamine users. The glucosamine users group was further divided into adherent, partially adherent, and non-adherent groups according to the medication adherence. New-onset cardiovascular diseases (CVD) events, coronary heart diseases (CHD), and stroke, were identified during the observational period. COX proportional regression models were used to estimate the risks. Of the 685,778 patients newly diagnosed with osteoarthritis including 240,419 glucosamine users and 445,359 non-users, the mean age was 56.49 (SD: 14.45) years and 59.35% were females. During a median follow-up of 6.13 years, 64,600 new-onset CVD, 26,530 CHD, and 17,832 stroke events occurred. Glucosamine usage was significantly associated with CVD (HR: 1.10; 95% CI: 1.08−1.11) and CHD (HR: 1.12; 95% CI: 1.09−1.15), but not with stroke (HR: 1.03; 95% CI: 0.99−1.06). The highest CVD risk was shown in the adherent group (HR: 1.68; 95% CI: 1.59−1.78), followed by the partially adherent group (HR: 1.26, 95% CI: 1.22−1.30), and the non-adherent group (HR: 1.03; 95% CI: 1.02−1.05), with a significant dose−response relationship (p-trend < 0.001). In this longitudinal study, adherent usage of glucosamine was significantly associated with a higher risk for cardiovascular diseases in patients with osteoarthritis.

Osteoarthritis, coronary artery disease, and myocardial infarction: A mendelian randomization study

Background

Observational studies indicate that osteoarthritis (OA) and coronary artery disease (CAD), as well as myocardial infarction (MI), are often diagnosed as comorbid diseases. We performed a bidirectional Mendelian randomization (MR) study to demonstrate whether there is a causal relationship between OA, CAD, and MI.

Methods

We extracted single nucleotide polymorphisms (SNPs) related to OA in the Genetics of Osteoarthritis (GO) Consortium as instrumental variables to assess whether OA is associated with CAD and MI in the CARDIoGRAMplusC4D 1,000 Genomes genome-wide association study (GWAS). In the reverse MR, we used CAD-associated and MI-associated SNPs to the GWAS of OA to analyze their causality. These GWASs included 766,690 individuals of OA, 184,305 individuals of CAD, and 166,065 individuals of MI. MR was conducted using several methods, including the inverse variance weighted (IVW) method, the weighted median method, the MR-Egger method, and the MR-Pleiotropy RESidual Sum and Outlier (MR-PRESSO) method.

Results

The forward causal effect of OA on CAD and MI was not observed. In reverse analysis, no causal effect was discovered for CAD on the risk of OA. Notably, we observed a causal association between MI and total OA [IVW odds ratio (OR) = 0.95, 95% CI = 0.93, 0.98, P = 4E−04] and spine OA (IVW OR = 0.92, 95% CI = 0.88, 0.97, P = 0.001) but a null association between MI and knee OA, hip OA, hand OA, and thumb OA.

Conclusion

This MR study identifies a potentially protective effect of genetically predicted MI on total and spine OA risks.

Effect of atorvastatin on skeletal muscles of patients with knee osteoarthritis: Post-hoc analysis of a randomised controlled trial

Objective

Populations with knee osteoarthritis (KOA) are at increased risk of cardiovascular disease, due to higher prevalence of risk factors including dyslipidaemia, where statins are commonly prescribed. However, the effect of statins on muscles and symptoms in this population is unknown. Thus, this study examined the effect of atorvastatin on muscle properties in patients with symptomatic KOA.

Design

Post-hoc analysis of a 2-year multicentre randomised, double-blind, placebo-controlled trial.

Setting

Australian community.

Participants

Participants aged 40–70 years (mean age 55.7 years, 55.6% female) with KOA who met the American College of Rheumatology clinical criteria received atorvastatin 40 mg daily (n = 151) or placebo (n = 153).

Main outcome measures

Levels of creatinine kinase (CK), aspartate transaminase (AST), and alanine transaminase (ALT) at 1, 6, 12, and 24 months; muscle strength (by dynamometry) at 12 and 24 months; vastus medialis cross-sectional area (CSA) on magnetic resonance imaging at 24 months; and self-reported myalgia.

Results

There were no significant between-group differences in CK and AST at all timespoints. The atorvastatin group had higher ALT than placebo group at 1 (median 26 vs. 21, p = 0.004) and 6 (25 vs. 22, p = 0.007) months without significant between-group differences at 12 and 24 months. Muscle strength increased in both groups at 24 months without between-group differences [mean 8.2 (95% CI 3.5, 12.9) vs. 5.9 (1.3, 10.4), p = 0.49]. Change in vastus medialis CSA at 24 months favoured the atorvastatin group [0.11 (−0.10, 0.31) vs. −0.23 (−0.43, −0.03), p = 0.02] but of uncertain clinical significance. There was a trend for more myalgia in the atorvastatin group (8/151 vs. 2/153, p = 0.06) over 2 years, mostly occurring within 6 months (7/151 vs. 1/153, p = 0.04).

Conclusions

In those with symptomatic KOA, despite a trend for more myalgia, there was no clear evidence of an adverse effect of atorvastatin on muscles, including those most relevant to knee joint health.

Association between hypertension and osteoarthritis: A systematic review and meta-analysis of observational studies

Objective

Literature examining the relationship between elevated blood pressure and osteoarthritis (OA) has yielded conflicting results. This study aimed to systematically review the relationship between hypertension and OA in both load-bearing and non-load-bearing joints.

Methods

A systematic literature search was performed on Embase, Emcare, MEDLINE and Ovid Nursing Database. The associations between hypertension and OA development in knees, hips and hands were analysed by calculating the odds ratio (OR).

Results

A total of 26 studies with 97,960 participants were included. The overall odds of having OA significantly increased in the people with hypertension compared to the normotensive ones (OR ​= ​1.60, 95%CI ​= ​1.33, 1.94). The association of hypertension with OA was detected in knee (OR ​= ​1.62, 95%CI ​= ​1.32, 1.98), not in hand (OR ​= ​1.19, 95%CI ​= ​0.92, 1.53). Moreover, there existed a stronger association of hypertension with radiographic knee OA (OR ​= ​1.89, 95%CI ​= ​1.40, 2.54) than symptomatic knee OA (OR ​= ​1.39, 95%CI ​= ​1.17, 1.65). The association between hypertension and radiographic knee OA remained statistically significant for the studies that adjusted for body mass index (BMI) (OR ​= ​1.42, 95%CI ​= ​1.13, 1.78), and was particularly strong in women (OR ​= ​2.27, 95%CI ​= ​1.17, 4.39).

Conclusion

A BMI-independent association between hypertension and radiographic knee OA existed with potential sex variation, which warrants further investigations into the underlying genetic, hormonal and environmental factors.

The translational potential of this article: Blood pressure has been reported to link with OA for years ago, however, its contribution to OA is still unclear and conflicted in different reports. This review indicated an intimate relationship between hypertension and structural damages of knee OA, rather than simply chronic joint pain, especially in women. This finding not only provides stronger support for further investigations into the causal risk factor, i.e. hypertension, of OA from tissue level to molecular level, but also putting forward a novel thinking in OA pathogenesis and its therapy strategies.

Orthopedic translation

This study further strengthen the association between hypertension and radiographic knee OA. It points in a vascular aetiology hypothesis of OA. It might open up a new avenue for repositioning anti-hypertensive medications for osteoarthritis treatment.

The association of clinical and structural knee osteoarthritis with physical activity in the middle-aged population: the NEO study

OBJECTIVE

To investigate if knee osteoarthritis (OA) is associated with lower physical activity in the general middle-aged Dutch population, and if physical activity is associated with patient-reported outcomes in knee OA.

DESIGN

Clinical knee OA was defined in the Netherlands Epidemiology of Obesity population using the ACR criteria, and structural knee OA on MRI. We assessed knee pain and function with the Knee Injury and Osteoarthritis Score (KOOS), health-related quality of life (HRQoL) with the Short Form-36, and physical activity (in Metabolic Equivalent of Task (MET) hours) with the Short Questionnaire to Assess Health-enhancing physical activity. We analysed the associations of knee OA with physical activity, and of physical activity with knee pain, function, and HRQoL in knee OA with linear regression adjusted for potential confounders.

RESULTS

Clinical knee OA was present in 14% of 6,212 participants, (mean age 56 years, mean BMI 27 kg/m², 55% women, 24% having any comorbidity) and structural knee OA in 12%. Clinical knee OA was associated with 9.60 (95% CI 3.70; 15.50) MET hours per week more physical activity, vs no clinical knee OA. Structural knee OA was associated with 3.97 (-7.82; 15.76) MET hours per week more physical activity, vs no structural knee OA. In clinical knee OA, physical activity was not associated with knee pain, function or HRQoL.

CONCLUSIONS

Knee OA was not associated with lower physical activity, and in knee OA physical activity was not associated with patient-reported outcomes. Future research should indicate the optimal treatment advice regarding physical activity for individual knee OA patients.

Osteoarthritis and risk of hospitalization for ambulatory care-sensitive conditions: a general population-based cohort study

OBJECTIVE

To determine the association between OA and risk of hospitalization for ambulatory care-sensitive conditions (HACSCs).

METHODS

We included all individuals aged 40-85 years who resided in Skåne, Sweden on 31 December 2005 with at least one healthcare consultation during 1998-2005 (n = 515 256). We identified those with a main diagnosis of OA between 1 January 1998 and 31 December 2016. People were followed from 1 January 2006 until an HACSC, death, relocation outside Skåne, or 31 December 2016 (whichever occurred first). OA status was treated as a time-varying covariate (those diagnosed before 1 January 2006 considered as exposed for whole study period). We assessed relative [hazard ratios (HRs) using Cox proportional hazard model] and absolute (hazard difference using additive hazard model) effects of OA on HACSCs adjusted for potential confounders.

RESULTS

Crude incidence rates of HACSCs were 239 (95% CI: 235, 242) and 151 (150, 152) per 10 000 person-years among OA and non-OA persons, respectively. The OA persons had an increased risk of HACSCs [HR (95% CI) 1.11 (1.09, 1.13)] and its subcategories of medical conditions except chronic obstructive pulmonary disease [HR (95% CI) 0.86 (0.81, 0.90)]. There were 20 (95% CI: 16, 24) more HACSCs per 10 000 person-years in OA compared with non-OA persons. While HRs for knee and hip OA were generally comparable, only knee OA was associated with increased risk of hospitalization for diabetes.

CONCLUSION

OA is associated with an increased risk of HACSCs, highlighting the urgent need to improve outpatient care for OA patients.

Hypertension meets osteoarthritis - revisiting the vascular aetiology hypothesis

Osteoarthritis (OA) is a whole-joint disease characterized by subchondral bone perfusion abnormalities and neovascular invasion into the synovium and articular cartilage. In addition to local vascular disturbance, mounting evidence suggests a pivotal role for systemic vascular pathology in the aetiology of OA. This Review outlines the current understanding of the close relationship between high blood pressure (hypertension) and OA at the crossroads of epidemiology and molecular biology. As one of the most common comorbidities in patients with OA, hypertension can disrupt joint homeostasis both biophysically and biochemically. High blood pressure can increase intraosseous pressure and cause hypoxia, which in turn triggers subchondral bone and osteochondral junction remodelling. Furthermore, systemic activation of the renin-angiotensin and endothelin systems can affect the Wnt-β-catenin signalling pathway locally to govern joint disease. The intimate relationship between hypertension and OA indicates that endothelium-targeted strategies, including re-purposed FDA-approved antihypertensive drugs, could be useful in the treatment of OA.

Prevalence, Impact, and Treatment of Co-Occurring Osteoarthritis in Patients With Stroke Undergoing Rehabilitation: A Review

BACKGROUND AND PURPOSE

Early, frequent rehabilitation is an important factor for optimizing stroke recovery outcomes. Medical comorbidities, such as osteoarthritis, that affect the ability to participate in rehabilitation could therefore have a detrimental impact on such outcomes. Both stroke and osteoarthritis are becoming more common in developed nations as the population ages. First-line osteoarthritis treatments, such as oral nonsteroidal anti-inflammatory drugs, are often avoided poststroke due to interaction with secondary prevention stroke risk-factor management. Our objective was to summarize the current literature concerning co-occurring osteoarthritis and stroke prevalence, its functional impact, and treatment options.

METHODS

Narrative review using a comprehensive literature search of PubMed, osteoarthritis, and stroke guidelines. Outcomes related to co-occurrence prevalence, osteoarthritis as a stroke risk-factor, osteoarthritis-related imaging and treatment were extracted and summarized descriptively. Overall quality of the evidence was summarized using Grading of Recommendations Assessment, Development and Evaluation.

RESULTS

We identified 23 studies and guidelines related to our objective. Overall quality of the evidence was very low.

CONCLUSIONS

Few trials have investigated the relationship between osteoarthritis and stroke, nor osteoarthritis-specific pain and function management for stroke survivors. High-quality research evaluating the impact of osteoarthritis on stroke rehabilitation is needed.

Current Epidemiology and Risk Factors for the Development of Hand Osteoarthritis

PURPOSE OF REVIEW

Hand osteoarthritis (hand OA), the most common peripheral arthritis in the world, is less studied than osteoarthritis (OA) of the knee and hip. However, it is uniquely situated to offer novel insight into OA as a disease process by removing weight-bearing as a confounder of systemic disease mechanisms. Here we review the epidemiology of hand OA and key risk factors for its development.

RECENT FINDINGS

Mounting evidence points to obesity as an important risk factor for hand OA development, with new evidence implicating a role for leptin and serum fatty acids. Disease progression in hand OA and specifically the erosive OA subtype may be associated with diabetes. New evidence supports an association between cardiovascular disease progression and symptomatic hand OA. Alcohol use may be associated with increased synovitis and erosive hand OA. Differences in ethnical distributions of hand OA have become more apparent, with a lower prevalence in Black patients compared to White patients. Novel genetic insights implicating the WNT gene pathway and IL-1β have led to novel potential targets in hand OA pathogenesis. Hand OA is a heterogeneous disease with many modifiable and non-modifiable risk factors that can determine disease severity and shed light on disease pathogenesis.

Mediation of the association between obesity and osteoarthritis by blood pressure, vessel wall stiffness and subclinical atherosclerosis

Objective

We investigated the role of blood pressure, vessel wall stiffness [pulse wave velocity (PWV)] and subclinical atherosclerosis markers [carotid intima-media thickness (cIMT), popliteal vessel wall thickness (pVWT)] as mediators of the association of obesity with OA.

Methods

We used cross-sectional data from a subset of the population-based NEO study (n = 6334). We classified clinical hand and knee OA by the ACR criteria, and structural knee OA, effusion and bone marrow lesions on MRI (n = 1285). cIMT was assessed with ultrasonography. pVWT was estimated on knee MRI (n = 1285), and PWV by abdominal velocity-encoded MRIs (n = 2580), in subpopulations. Associations between BMI and OA were assessed with logistic regression analyses, adjusted for age, sex and education. Blood pressure, cIMT, pVWT and PWV were added to the model to estimate mediation.

Results

The population consisted of 55% women, with a mean (s.d.) age of 56(6) years. Clinical hand OA was present in 8%, clinical knee OA in 10%, and structural knee OA in 12% of participants. BMI was positively associated with all OA outcomes. cIMT partially mediated the association of BMI with clinical hand OA [10.6 (6.2; 30.5)%], structural knee OA [3.1 (1.9; 7.3)%] and effusion [10.8 (6.0; 37.6)%]. Diastolic blood pressure [2.1 (1.6; 3.0)%] minimally mediated the association between BMI and clinical knee OA. PWV and pVWT did not mediate the association between BMI and OA.

Conclusions

cIMT and diastolic blood pressure minimally mediated the association of BMI with OA. This suggests that such mediation is trivial in the middle-aged population.

Osteocyte Dysfunction in Joint Homeostasis and Osteoarthritis

Structural disturbances of the subchondral bone are a hallmark of osteoarthritis (OA), including sclerotic changes, cystic lesions, and osteophyte formation. Osteocytes act as mechanosensory units for the micro-cracks in response to mechanical loading. Once stimulated, osteocytes initiate the reparative process by recruiting bone-resorbing cells and bone-forming cells to maintain bone homeostasis. Osteocyte-expressed sclerostin is known as a negative regulator of bone formation through Wnt signaling and the RANKL pathway. In this review, we will summarize current understandings of osteocytes at the crossroad of allometry and mechanobiology to exploit the relationship between osteocyte morphology and function in the context of joint aging and osteoarthritis. We also aimed to summarize the osteocyte dysfunction and its link with structural and functional disturbances of the osteoarthritic subchondral bone at the molecular level. Compared with normal bones, the osteoarthritic subchondral bone is characterized by a higher bone volume fraction, a larger trabecular bone number in the load-bearing region, and an increase in thickness of pre-existing trabeculae. This may relate to the aberrant expressions of sclerostin, periostin, dentin matrix protein 1, matrix extracellular phosphoglycoprotein, insulin-like growth factor 1, and transforming growth factor-beta, among others. The number of osteocyte lacunae embedded in OA bone is also significantly higher, yet the volume of individual lacuna is relatively smaller, which could suggest abnormal metabolism in association with allometry. The remarkably lower percentage of sclerostin-positive osteocytes, together with clustering of Runx-2 positive pre-osteoblasts, may suggest altered regulation of osteoblast differentiation and osteoblast-osteocyte transformation affected by both signaling molecules and the extracellular matrix. Aberrant osteocyte morphology and function, along with anomalies in molecular signaling mechanisms, might explain in part, if not all, the pre-osteoblast clustering and the uncoupled bone remodeling in OA subchondral bone.

The Association of Osteoarthritis and Related Pain Burden to Incident Alzheimer's Disease and Related Dementias: A Retrospective Cohort Study of U.S. Medicare Beneficiaries

BACKGROUND

Emerging evidence suggests osteoarthritis (OA) and related symptom burden may increase risk for Alzheimer's disease and related dementias (ADRD). However, longitudinal studies are sparse, and none have examined the potential mediating effects of mood or sleep disorders.

OBJECTIVE

To determine the association of OA and related pain to incident ADRD in U.S. elders.

METHODS

In this retrospective cohort study, we used baseline and two-year follow-up data from linked Medicare claims and Medicare Current Beneficiary Survey files (11 pooled cohorts, 2001-2013). The study sample comprised 16,934 community-dwelling adults≥65 years, ADRD-free at baseline and enrolled in fee-for-service Medicare. Logistic regression was used to assess the association of OA and related pain (back, neck, joint, neuropathic) to incident ADRD, explore the mediating inlfuence of mood and insomnia-related sleep disorders, and (sensitivity analyses) account for potential survival bias.

RESULTS

Overall, 25.5% of beneficiaries had OA at baseline (21.0% with OA and pain); 1149 elders (5.7%) were subsequently diagnosed with ADRD. Compared to beneficiaries without OA, those with OA were significantly more likely to receive a diagnosis of incident ADRD after adjustment for sociodemographics, lifestyle characteristics, comorbidities, and medications (adjusted odds ratio (AOR) = 1.23 (95% confidence interval (CI) 1.06, 1.42). Elders with OA and pain at baseline were significantly more likely to be diagnosed with incident ADRD than were those without OA or pain (AOR = 1.31, CI 1.08, 1.58). Sensitivity analyses yielded similar findings. Inclusion of depression/anxiety, but not sleep disorders, substantially attenuated these associations.

CONCLUSION

Findings of this study suggest that: OA is associated with elevated ADRD risk, this association is particularly pronounced in those with OA and pain, and mood disorders may partially mediate this relationship.

Genetic and Epigenetic Fine-Tuning of TGFB1 Expression Within the Human Osteoarthritic Joint

OBJECTIVE

Osteoarthritis (OA) is an age-related disease characterized by articular cartilage degeneration. It is largely heritable, and genetic screening has identified single-nucleotide polymorphisms (SNPs) marking genomic risk loci. One such locus is marked by the G>A SNP rs75621460, downstream of TGFB1. This gene encodes transforming growth factor β1, the correct expression of which is essential for cartilage maintenance. This study investigated the regulatory activity of rs75621460 to characterize its impact on TGFB1 expression in disease-relevant patient samples (n = 319) and in Tc28a2 immortalized chondrocytes.

METHODS

Articular cartilage samples from human patients were genotyped, and DNA methylation levels were quantified using pyrosequencing. Gene reporter and electrophoretic mobility shift assays were used to determine differential nuclear protein binding to the region. The functional impact of DNA methylation on TGFB1 expression was tested using targeted epigenome editing.

RESULTS

The analyses showed that SNP rs75621460 was located within a TGFB1 enhancer region, and the OA risk allele A altered transcription factor binding, with decreased enhancer activity. Protein complexes binding to A (but not G) induced DNA methylation at flanking CG dinucleotides. Strong correlations between patient DNA methylation levels and TGFB1 expression were observed, with directly opposing effects in the cartilage and the synovium at this locus. This demonstrated biologic pleiotropy in the impact of the SNP within different tissues of the articulating joint.

CONCLUSION

The OA risk SNP rs75621460 impacts TGFB1 expression by modulating the function of a gene enhancer. We propose a mechanism by which the SNP impacts enhancer function, providing novel biologic insight into one mechanism of OA genetic risk, which may facilitate the development of future pharmacologic therapies.

Criterion validity of The International Physical Activity Questionnaire-Short Form (IPAQ-SF) for use in clinical practice in patients with osteoarthritis

BACKGROUND

To tailor physical activity treatment programs for patients with osteoarthritis, clinicians need valid and feasible measurement tools to evaluate habitual physical activity. The widely used International Physical Activity Questionnaire-Short Form (IPAQ-SF) is not previously validated in patients with osteoarthritis.

PURPOSE

To assess the concurrent criterion validity of the IPAQ-SF in patients with osteoarthritis, using an accelerometer as a criterion-method.

METHOD

Patients with osteoarthritis (n = 115) were recruited at The Division of Rheumatology and Research at Diakonhjemmet Hospital (Oslo, Norway). Physical activity was measured by patients wearing an accelerometer (ActiGraph wGT3X-BT) for seven consecutive days, followed by reporting their physical activity for the past 7 days using the IPAQ-SF. Comparison of proportions that fulfilled physical activity recommendations as measured by the two methods were tested by Pearson Chi-Square analysis. Differences in physical activity levels between the IPAQ-SF and the accelerometer were analyzed with Wilcoxon Signed-Rank Test and Spearman rank correlation test. Bland-Altman plots were used to visualize the concurrent criterion validity for total- and intensity-specific physical activity levels.

RESULTS

In total, 93 patients provided complete physical activity data, mean (SD) age was 65 (8.7) years, 87% were women. According to the IPAQ-SF, 57% of the patients fulfilled the minimum physical activity recommendations compared to 31% according to the accelerometer (p = 0.043). When comparing the IPAQ-SF to the accelerometer we found significant under-reporting of total physical activity MET-minutes (p = < 0.001), sitting (p = < 0.001) and walking (p < 0.001), and significant over-reporting of moderate-to-vigorous physical activity (p < 0.001). For the different physical activity levels, correlations between the IPAQ-SF and the accelerometer ranged from rho 0.106 to 0.462. The Bland-Altman plots indicated an increased divergence between the two methods with increasing time spent on moderate-to-vigorous intensity physical activity.

CONCLUSION

Physical activity is a core treatment of osteoarthritis. Our finding that patients tend to over-report activity of higher intensity and under-report low-intensity activity and sitting-time is of clinical importance. We conclude that the concurrent criterion validity of the IPAQ-SF was weak in patients with osteoarthritis.

Psychometric evaluation of the Arthritis Self-Efficacy Scale in Chinese adults with rheumatic diseases: a cross-sectional study

OBJECTIVE

The Arthritis Self-Efficacy Scale (ASES) was designed to assess the degree of self-efficacy among patients with arthritis. Though the original English version of this instrument has shown a high degree of reliability and validity, a Chinese version of this scale has yet to be validated. Therefore, the aim of this cross-sectional study was to evaluate the psychometric characteristics of the Chinese version of ASES (C-ASES) in a population of Chinese adults with rheumatic diseases (RDs).

METHODS

After completing backward translation and expert validity, a convenient sample of 258 qualified participants with RDs from a hospital in Taiwan were recruited to explore the content validity, concurrent validity, construct validity, internal consistency reliability and test-retest reliability of C-ASES.

RESULTS

The C-ASES has demonstrated acceptable internal consistency and test-retest reliability, with a Cronbach α of 0.91 and intraclass correlation coefficient of 0.89, respectively. Concurrent validity was acceptable, with significant correlation between the subscales of the C-ASES and perceived depressive symptoms, as measured by the Taiwanese Depression Questionnaire (p<0.05). The exploratory factor analysis revealed a three-factor solution (physical function, experienced pain and other symptoms) corresponding to the structure of the original instrument, which accounted for 59.78% of the total variance.

CONCLUSION

Empirical data support the assertion that C-ASES is a reliable and valid screening instrument to assess self-efficacy in Chinese-speaking patients with RDs. C-ASES may be useful as a reference guide in providing appropriate interventions for bolstering self-efficacy among Chinese-speaking patients with RDs.

Risk of venous thromboembolism in knee, hip and hand osteoarthritis: a general population-based cohort study

OBJECTIVES

Osteoarthritis is a leading cause of immobility and joint replacement, two strong risk factors for venous thromboembolism (VTE). We aimed to examine the relation of knee, hip and hand osteoarthritis to the risk of VTE and investigate joint replacement as a potential mediator.

METHODS

We conducted three cohort studies using data from The Health Improvement Network. Up to five individuals without osteoarthritis were matched to each case of incident knee (n=20 696), hip (n=10 411) or hand (n=6329) osteoarthritis by age, sex, entry time and body mass index. We examined the relation of osteoarthritis to VTE (pulmonary embolism and deep vein thrombosis) using a multivariable Cox proportional hazard model.

RESULTS

VTE developed in 327 individuals with knee osteoarthritis and 951 individuals without osteoarthritis (2.7 vs 2.0 per 1000 person-years), with multivariable-adjusted HR being 1.38 (95% CI 1.23 to 1.56). The indirect effect (HR) of knee osteoarthritis on VTE through knee replacement was 1.07 (95% CI 1.01 to 1.15), explaining 24.8% of its total effect on VTE. Risk of VTE was higher in hip osteoarthritis than non-osteoarthritis (3.3 vs 1.8 per 1000 person-years; multivariable-adjusted HR=1.83, 95% CI 1.56 to 2.13). The indirect effect through hip replacement yielded an HR of 1.14 (95% CI 1.04 to 1.25), explaining 28.1% of the total effect. No statistically significant difference in VTE risk was observed between hand osteoarthritis and non-osteoarthritis (1.5 vs 1.6 per 1000 person-years; multivariable-adjusted HR=0.88, 95% CI 0.67 to 1.16).

CONCLUSION

Our large population-based cohort study provides the first evidence that knee or hip osteoarthritis, but not hand osteoarthritis, was associated with an increased risk of VTE, and such an association was partially mediated through knee or hip replacement.

Gait initiation and lateral wedge insole for individuals with early knee osteoarthritis

BACKGROUND

People with knee osteoarthritis are at higher risk of postural deficits and locomotor adaptations which could be manifested in transient tasks like gait initiation. To better understand the effect of early knee osteoarthritis on gait initiation, we measured the gait initiation in two groups of early knee osteoarthritis and healthy age-matched controls and assessed the effect of lateral wedge insole in knee osteoarthritis group.

METHODS

Twenty-one individuals with early knee osteoarthritis, mean (SD) age = 53.1 (7.4, years), and 19 age- and sex-matched asymptomatic healthy individuals, mean (SD) age = 47.5 (11.2, years), participated. Centre of pressure trajectories were used to quantify the two phases of gait initiation in barefoot condition: anticipatory postural adjustment, and locomotor phase. The immediate and four-week effect of lateral wedge insole and shod condition were also compared for individuals in knee osteoarthritis group.

FINDINGS

Longer duration of anticipatory postural adjustment phase (P = 0.046), locomotor phase (P = 0.049), and total duration of gait initiation (P = 0.035) with lower length and velocity of the center of pressure trajectories in anticipatory postural adjustment phase (P = 0.002, and 0.008, respectively) were observed in knee osteoarthritis group compared to controls. Lateral wedge insole could increase the length and velocity of the centre of pressure in locomotor phase compared to barefoot condition (P = 0.001, and 0.002, respectively).

INTERPRETATION

Our study outlined that people with early knee osteoarthritis adopt different gait initiation strategies mainly in postural preparation phase. The potential effect of lateral wedge insole was shown with better performance of the locomotor phase.

CLINICAL TRIAL REGISTRY NUMBER

IRCT2016060628310N1.

Determining the feasibility of a trial to evaluate the effectiveness of phototherapy versus placebo at reducing pain during physical activity for people with knee osteoarthritis: a pilot randomized controlled trial

BACKGROUND

Although practice guidelines recommend physical activity and exercise for the management of knee osteoarthritis, pain is a common barrier to participation. Phototherapy has been shown to reduce pain intensity for people with knee osteoarthritis, but it is unclear if it reduces pain during physical activity or contributes to improved rehabilitation outcomes.

OBJECTIVE

The aim of this study is to assess the feasibility of performing a fully powered randomized controlled trial (RCT) comparing an active phototherapy intervention versus placebo on pain during physical activity for people with knee osteoarthritis.

METHODS

A pilot RCT was conducted to test the feasibility of a trial comparing 8-sessions (4 weeks) of active phototherapy versus placebo. People were able to participate if they (1) were an English speaking adult (> 18 years of age), (2) had received a diagnosis of knee osteoarthritis from a physician, and (3) self-reported experiencing pain and disability related to their knee osteoarthritis for > 3 months. Primary outcomes were the feasibility of participant recruitment, retention, assessment procedures, and maintaining high treatment fidelity. Secondary outcomes piloted for a full trial included pain during physical activity (primary outcome of full trial); self-reported pain severity, physical function, stiffness, adherence to prescribed exercise, global rating of change, patient satisfaction, and adverse events; 6-min walk test; and pressure pain threshold.

RESULTS

Twenty participants (4 men; 16 women) with knee osteoarthritis and a mean age of 63.95 (SD: 9.27) years were recruited over a 3-week period (6.7 participants per week). Fifteen out of 20 (75%) of participants completed the primary outcome assessment at 4 weeks and 19/20 (95%) of participants were retained and completed the final 16-week assessment. Overall, 89% of all assessment items were completed by participants across all time-points. Fifteen out of 20 participants (75%) completed all 8 treatment sessions. Treatment fidelity was 100% for all completed treatment sessions. No adverse events were reported by participants in either group.

CONCLUSIONS

Results suggest that the trial methodology and intervention are feasible for implementation in a fully powered randomized controlled trial to determine the effectiveness of phototherapy at reducing pain during physical activity for people with knee osteoarthritis.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT04234685 , January 21, 2020-Retrospectively registered.

Osteoarthritis and incidence of stroke and transient ischemic attack in 320,136 adults followed in general practices in the United Kingdom

OBJECTIVE

The goal of this study was to investigate the relationship of osteoarthritis with stroke and transient ischemic attack in the United Kingdom.

METHODS

This study included patients who received a first diagnosis of osteoarthritis in one of 256 general practices in the United Kingdom between 1997 and 2016 (index date). Patients without osteoarthritis were matched (1:1) to those with osteoarthritis using propensity scores based on sex, age, index year, general practice, and vascular risk factors documented in the 12 months prior to the index date (hypertension, obesity, diabetes mellitus, dyslipidemia, and atrial fibrillation). For individuals without osteoarthritis, the index date corresponded to a randomly selected visit date between 1997 and 2016. The relationship between osteoarthritis and the incidence of both stroke and transient ischemic attack was studied using Kaplan-Meier curves and Cox regression analyses.

RESULTS

This study included 160,068 patients with osteoarthritis and 160,068 patients without osteoarthritis (61.6% women; mean age [standard deviation] 64.2 [14.2] years). The 10-year incidence of stroke (4.5% versus 3.0%) and transient ischemic attack (3.3% versus 2.0%) was significantly higher in individuals with than in those without osteoarthritis. The Cox regression analyses also showed that osteoarthritis was positively associated with both stroke (hazard ratio [HR]=1.45, 95% confidence interval [CI]=1.39-1.51) and transient ischemic attack (HR=1.55, 95% CI=1.47-1.63).

CONCLUSIONS

These findings suggest that osteoarthritis may be associated with an increase in the incidence of stroke and transient ischemic attack. Further research of longitudinal design is warranted to confirm or reject these results.

Multi-tissue epigenetic analysis of the osteoarthritis susceptibility locus mapping to the plectin gene PLEC

OBJECTIVE

In cartilage, the osteoarthritis (OA) associated single nucleotide polymorphism (SNP) rs11780978 correlates with differential expression of PLEC, and with differential methylation of PLEC CpG dinucleotides, forming eQTLs and mQTLs respectively. This implies that methylation links chondrocyte genotype and phenotype, thus driving the functional effect of this genetic risk signal. PLEC encodes plectin, a cytoskeletal protein that enables tissues to respond to mechanical forces. We sought to assess whether these PLEC functional effects were cartilage specific.

METHOD

Cartilage, fat pad, synovium and peripheral blood were collected from patients undergoing arthroplasty. PLEC CpGs were analysed for mQTLs and allelic expression imbalance (AEI) was performed to test for eQTLs. Plectin was knocked down in a mesenchymal stem cell (MSC) line using CRISPR/Cas9 and cells phenotyped by RNA-sequencing.

RESULTS

mQTLs were discovered in fat pad, synovium and blood. Their effects were however stronger in the joint tissues and of comparable effect between these tissues. We observed AEI in synovium in the same direction as for cartilage and correlations between methylation and PLEC expression. Knocking-down plectin impacted on pathways reported to have a role in OA, including Wnt signalling, glycosaminoglycan biosynthesis and immune regulation.

CONCLUSIONS

Synovium is also a target of the rs11780978 OA association functionally operating on PLEC. In fat pad, mQTLs were identified but these did not correlate with PLEC expression, suggesting the functional effect is not joint-wide. Our study highlights interplay between genetic risk, DNA methylation and gene expression in OA, and reveals clear differences between tissues from the same diseased joint.

Reductions of cardiovascular and metabolic risk factors after a 14-week periodized training model in patients with knee osteoarthritis: a randomized controlled trial

INTRODUCTION/OBJECTIVE

To evaluate the effects of a periodized circuit training (CT) compared with a conventional strength training (ST) and an educational protocol (EP) on body composition, metabolic parameters, muscle strength, pain, and physical performance in patients with knee osteoarthritis (KOA).

METHOD

This study followed a randomized controlled trial design. A sample of sixty-one patients with KOA, 40-65 years old and BMI < 30 kg/m², were randomly divided into three 14-week protocols: CT, ST, or EP. The CT performed whole body exercises organized in circuit, 3 times a week. The ST performed conventional resistance exercises also 3 times a week, and the EP joined in educational meetings twice a month. Body composition (dual-energy X-ray absorptiometry (DXA)); metabolic parameters (abdominal obesity, triglyceride, HDL, blood pressure and fasting glucose), knee maximal isometric voluntary contraction (MIVC) extension and flexion, performance-based tests (40-m walk test, 30-s chair test, and stair climb test), self-reported pain, stiffness, and physical function (WOMAC) and pain catastrophism were evaluated at baseline and follow-up. Repeated measures ANOVA were used to compare differences between groups (CTxSTxEP) at the different times of assessment (baseline × follow-up). When group-time interaction was found, a one-way ANOVA, followed by a Bonferroni post hoc test, was used to compare groups in each time point; while a paired t test was used to verify the time effect in each group. Additionally, the training effect was analyzed in terms of the percent change (Δ%). Effect size was calculated for post intervention (week 14) between groups. For all analyses a significance level of 5% was adopted (p < 0.05).

RESULTS

The CT was the only protocol that presented significant lower body mass (p = 0.018; Δ% = - 1.4), fat mass (p = 0.017; Δ% = - 10.3), %fat mass (p < 0.001; Δ% = - 13.9), adipose indices (%fat trunk/%fat legs p = 0.031; Δ% = 7.8; fat mass/height² p = 0.011; Δ% = - 15.1; trunk/limb fat mass p = 0.012; Δ% = - 8.2; visceral adipose tissue (VAT) volume (cm³) p = 0.039; Δ% = - 11.6; VAT area (cm²) p = 0.044; Δ% = - 12.2), blood pressure levels (SBP p = 0.042; Δ% = - 3.4 and DBP p = 0.001; Δ% = - 4.9), higher lean mass and HDL (p < 0.001; Δ% = 5.9) compared to baseline. CT and ST presented lower WOMAC pain, stiffness and physical function (p < 0.001; Δ% = - 64.0 for CT and p < 0.001; Δ% = 0.001; Δ% = - 46.4 for ST in WOMAC total score, pain catastrophizing (p < 0.001; Δ% = - 66.7 for CT and p < 0.001; Δ% = - 61.5 for ST) a higher functional performance (30 s chair test: p < 0.001; Δ% = 45.7 for CT and p < 0.001; Δ% = 26.9 for ST; 40 m walk test: p < 0.001; Δ% = 26.7 for CT and p < 0.001; Δ% = 12.5 for ST; stair climb test: p = 0.002; Δ% = - 33.9 for CT and p < 0.001; Δ% = - 18.8 for ST) and knee extension MIVC (p < 0.001; Δ% = 21.92 for CT and p < 0.001; Δ% = 30.25 for ST).

CONCLUSION

A periodized CT model reduces visceral adipose tissue, SBP and DBP, and improves HDL, important cardiovascular and metabolic risk factors, in patients with KOA. Both trained groups (CT and ST) improve self-reported clinical symptoms, muscle strength, and physical performance in this sample.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov , NCT02761590 (registered on May 4, 2016).

KEY POINTS

• A 14-week periodized circuit training reduces visceral adipose tissue, systolic and diastolic blood pressure, and improves HDL blood levels in patients with knee osteoarthritis. • Both periodized circuit training and conventional strength training improve clinical symptoms, functional performance and muscle strength in this sample.

Association between metabolic syndrome and hip osteoarthritis in middle-aged men and women from the general population

OBJECTIVE

To investigate the impact of metabolic syndrome and its components on osteoarthritis of the hip joints compared to a healthy cohort in the KORA MRI-study.

METHODS

Randomly selected men and women from the general population were classified as having metabolic syndrome, defined as presence of central obesity plus two of the following four components: elevated blood pressure (BP), elevated fasting glucose, elevated triglycerides (TG) and low HDL-cholesterol (HDL-c), or as controls without metabolic syndrome. Therefore, each subject underwent detailed assessment of waist circumference as well as fasting glucose, systolic and diastolic BP, TG, and HDL-c concentrations as well as a full-body MR scan. MR measurements were performed on a 3 Tesla scanner (Magnetom Skyra, Siemens) including a dual-echo Dixon and a T2 SS-FSE sequence for anatomical structures. In order to quantify osteoarthritis of the hip, assessment was performed by two independent, experienced radiologists for joint gap narrowing, osteophytic lipping and subchondral changes (e.g. sclerosis, pseudocysts). Associations between metabolic syndrome components and hip degeneration were estimated by logistic regression models providing odds ratios.

RESULTS

Among 354 included participants (mean age: 56.1 ± 9.2 years; 55.4% male), 119 (34%) had metabolic syndrome, while 235 (66%) were part of the control group. Except for elevated blood glucose (p = 0.02), none of the metabolic syndromes' component was independently associated with osteoarthritis. Multivariable adjusted ORs for osteoarthritis of the right hip were 1.00 (95% CI 0.98;1.03), 1.00 (95% CI 0.99;1.00), 1.01 (95% CI 0.99;1.03), 1.00 (95% CI 0.97;1.04) and 1.01 (95% CI 0.96;1.06), and for the left hip 1.00 (95% CI 0.98;1.03), 1.00 (95% CI 1.00;1.01), 1.01 (95% CI 0.99;1.03), 0.99 (95% CI 0.96;1.02) and 1.04 (95% CI 0.99;1.09) for waist circumference, triglyceride, HDL-c and systolic and diastolic BP, respectively. Blood glucose was a borderline non-dependent factor for osteoarthritis of the right hip (OR: 1.02 (95% CI 1.0;1.04); p = 0.05). Furthermore, the compound metabolic syndrome was not significantly associated (OR left hip: 1.53 (95% CI 0.8;2.92), p = 0.20; OR right hip: 1.33 (95% CI 0.72;2.45), p = 0.37) with osteoarthritis of the hip joint. Age as well as gender (left hip) were the only parameters in univariate and multivariate analysis to be significantly associated with osteoarthritis of the hip joint.

CONCLUSION

The compound metabolic syndrome showed no association with osteoarthritis of the hip joint. Age was the only parameter to be dependently and independently associated to osteoarthritis of both hip joints, while elevated blood glucose was independently associated with degeneration of the right hip joint.

Effects of Comorbid Cardiovascular Disease and Diabetes on Hand Osteoarthritis, Pain, and Functional State Transitions: The Johnston County Osteoarthritis Project

OBJECTIVE

The purpose of this study is to examine the course of hand osteoarthritis (HOA) and its relationship with cardiovascular disease (CVD) and diabetes (DM).

METHODS

Data were collected at 3 timepoints from 845 Johnston County Osteoarthritis Project participants (two-thirds women, one-third African Americans, mean age 60 yrs) with and without HOA, CVD, or DM. A diagnosis of radiographic HOA (rHOA) required a Kellgren-Lawrence severity grade of ≥ 2 in at least 3 joints in each hand. A 4-state progressive model included transitions based on rHOA and pain or function as defined using the Australian/Canadian HOA Index (AUSCAN). Markov multistate models estimated HR (aHR) and 95% CI for associations between DM or CVD and specific state transitions, adjusting for baseline and time-varying covariates.

RESULTS

Participants with DM (vs those without DM) were more likely to experience worsening pain with rHOA. Individuals who had or developed CVD (vs those who did not) were significantly less likely to experience symptomatic improvement, regardless of rHOA status. Those with DM or CVD (vs those without these comorbidities) were less likely to experience improvement in function, although this was statistically significant only for those with DM and no rHOA.

CONCLUSION

Overall, having or developing DM and/or CVD reduced the likelihood of symptomatic and functional improvement over time, suggesting an effect of comorbid CVD and DM on the clinical and radiographic course of HOA. Additional studies are needed to confirm these findings.

Understanding Atherosclerosis Through an Osteoarthritis Data Set

Atherosclerotic cardiovascular disease remains a worldwide epidemic and one of the leading causes of death nowadays. Vessel wall imaging can be used to understand the development and progression of atherosclerosis, but it is rarely done because of the high cost. We recently identified the Osteoarthritis Initiative, a large prospective cohort study of knee osteoarthritis, which might serve as a valuable source for atherosclerosis research with its serial knee magnetic resonance imaging data. We have found that these images are suitable for vessel wall image analysis of the lower extremity arteries. Here, we will introduce the Osteoarthritis Initiative data set and explain why it could be used for cardiovascular research purposes. Also, we will briefly comment on peripheral artery atherosclerosis as it is covered in the Osteoarthritis Initiative image data set and review the use of vessel wall imaging for studying atherosclerosis. We think data mining of imaging studies, not originally designed on cardiovascular research, can not only maximize the value of the imaging data set but also boost our understanding of atherosclerosis.

Co-occurrence of Chronic Musculoskeletal Pain and Cardiovascular Diseases: A Systematic Review with Meta-analysis

Objective

To determine the magnitude of the association between cardiovascular disease and chronic musculoskeletal pain.

Design

Systematic review with meta-analysis.

Methods

A comprehensive search was performed in five electronic databases. Population-based studies reporting the prevalence of cardiovascular diseases in adults stratified by chronic musculoskeletal pain status were considered eligible. Two independent reviewers performed the screening of the records following the inclusion criteria, extracted data, and evaluated the risk of bias of the included studies using an assessment tool of risk of bias for observational studies. In addition, we assessed the overall quality of evidence using an adaptation of the GRADE approach for prognosis.

Results

Twenty studies were included in this review. There was high-quality evidence that people with chronic musculoskeletal pain are 1.91 times more likely to report having a cardiovascular disease compared with those without chronic musculoskeletal pain (risk ratio = 1.91, 95% confidence interval = 1.64–2.21).

Conclusions

Our findings demonstrated associations between chronic musculoskeletal pain and any cardiovascular diseases. Future studies are still warranted to better understand the association between chronic musculoskeletal pain and the specific types of cardiovascular diseases.

Prioritization of PLEC and GRINA as Osteoarthritis Risk Genes Through the Identification and Characterization of Novel Methylation Quantitative Trait Loci

OBJECTIVE

To identify methylation quantitative trait loci (mQTLs) correlating with osteoarthritis (OA) risk alleles and to undertake mechanistic characterization as a means of target gene prioritization.

METHODS

We used genome-wide genotyping and cartilage DNA methylation array data in a discovery screen of novel OA risk loci. This was followed by methylation, gene expression analysis, and genotyping studies in additional cartilage samples, accompanied by in silico analyses.

RESULTS

We identified 4 novel OA mQTLs. The most significant mQTL contained 9 CpG sites where methylation correlated with OA risk genotype, with 5 of the CpG sites having P values <1 × 10^-10 . The 9 CpG sites reside in an interval of only 7.7 kb within the PLEC gene and form 2 distinct clusters. We were able to prioritize PLEC and the adjacent gene GRINA as independent targets of the OA risk. We identified PLEC and GRINA expression QTLs operating in cartilage, as well as methylation-expression QTLs operating on the 2 genes. GRINA and PLEC also demonstrated differential expression between OA hip and non-OA hip cartilage.

CONCLUSION

PLEC encodes plectin, a cytoskeletal protein that maintains tissue integrity by regulating intracellular signaling in response to mechanical stimuli. GRINA encodes the ionotropic glutamate receptor TMBIM3 (transmembrane BAX inhibitor 1 motif-containing protein family member 3), which regulates cell survival. Based on our results, we hypothesize that in a joint predisposed to OA, expression of these genes alters in order to combat aberrant biomechanics, and that this is epigenetically regulated. However, carriage of the OA risk-conferring allele at this locus hinders this response and contributes to disease development.

Expression analysis of the osteoarthritis genetic susceptibility mapping to the matrix Gla protein gene MGP

BACKGROUND

Osteoarthritis (OA) is a common disease of older individuals that impacts detrimentally on the quality and the length of life. It is characterised by the painful loss of articular cartilage and is polygenic and multifactorial. Genome-wide association scans have highlighted over 90 osteoarthritis genetic signals, some of which reside within or close to highly plausible candidate genes. An example is an association to polymorphisms within and adjacent to the matrix Gla protein gene MGP. We set out to undertake a functional study of this gene.

METHODS

Nucleic acid was extracted from cartilage, infrapatellar fat pad, synovium, trabecular bone, trapezium and peripheral whole blood from OA patients and also from mesenchymal stem cells (MSCs) subjected to chondrogenesis. Expression of MGP was measured by quantitative PCR (qPCR), RNA-sequencing and allelic expression imbalance (AEI) analysis. Matrix Gla protein was depleted in chondrocytes by knocking down MGP expression using RNA interference (RNAi) and the effect on a range of genes assessed by qPCR.

RESULTS

MGP is expressed in joint tissues, blood and chondrocytes cultured from MSCs. There is a higher expression in diseased versus non-diseased cartilage. Polymorphisms that are associated with OA also correlate with the expression of MGP, with the OA risk-conferring allele showing significantly reduced expression in cartilage, fat pad and synovium but increased expression in blood. Depletion of Matrix Gla protein had a significant effect on the majority of genes tested, with an increased expression of catabolic genes that encode enzymes that degrade cartilage.

CONCLUSIONS

MGP expression is subject to cis-acting regulators that correlate with the OA association signal. These are active in a range of joint tissues but have effects which are particularly strong in cartilage. An opposite effect is observed in blood, highlighting the context-specific nature of the regulation of this gene's expression. Recapitulation of the genetic deficit in cartilage chondrocytes is pro-catabolic.

Cause-specific mortality in osteoarthritis of peripheral joints

PURPOSE

To estimate cause-specific mortality in osteoarthritis patients compared to the general population.

METHODS

We identified all residents in southern Sweden aged 45-84 years in 2003. Through the Skåne Healthcare Register (SHR) we identified those diagnosed with osteoarthritis in peripheral joints between 1998 and 2003. We followed all residents from 2004 until relocation outside of the region, death, or end of 2014. We classified the underlying cause of death from death certificates into: cardiovascular and neoplasms, diabetes, infections, dementia, diseases of digestive system, or other causes. For estimation, we used multi-state adjusted Cox proportional hazards models.

RESULTS

We identified 15,901 patients (mean age [SD] 67 years [10], 41% men) with prevalent doctor-diagnosed osteoarthritis in knee, 9347 in hip, 4004 in hand and 5447 in other peripheral joints among 469,177 residents. For most causes of death in osteoarthritis patients, we found no increased mortality, with hazard ratios (HRs) close to 1, similar for men and women. However, for knee and hip osteoarthritis and cardiovascular death, HRs were non proportional and increased to 1.19 (95%CI 1.10, 1.28) and 1.13 (1.03, 1.24) during 9-11 years of follow-up, mostly due to excess mortality from chronic ischemic heart diseases and heart failure.

CONCLUSIONS

The risk of cardiovascular excess deaths increases with duration of knee and hip osteoarthritis. The major contributors are chronic ischemic heart diseases and heart failure. Our results call for improved implementation of osteoarthritis treatment guidelines, with major focus on interventions to address mobility limitations and maintaining or increase physical activity level.

Relationship between objectively measured lifestyle factors and health factors in patients with knee osteoarthritis: The STROBE Study

The purpose of this study was to investigate the association between objectively-measured lifestyle factors and health factors in patients with knee osteoarthritis (OA).In this cross-sectional study, 52 patients with knee OA were examined. Lifestyle factors were measured using a wearable smartwatch (step counts, walking distance, calorie consumption, sleep hours) and by self-report (eating speed). Body mass index (BMI), waist circumference, blood pressure, muscle strength of knee extensor and hip abductor, knee pain, symptoms, daily living function, sports recreation function, quality of life by knee injury and OA outcome score (KOOS) were measured to obtain data on health factors. Correlations and regression analysis were used to analyze the relationship between lifestyle factors and health factors.KOOS subscales (pain, symptom, daily living function) and hip abductor strength were positively correlated with daily step count, which was the only independently contributing lifestyle factor. Additionally, knee pain duration and diastolic blood pressure were negatively correlated with daily step count. BMI and waist circumference showed no correlation with physical activity data, but were negatively correlated with sleep duration and eating speed.The findings of this study contribute to expanding the knowledge on how lifestyle habits of older patients with knee OA contribute to their health status. Daily step counts were associated with knee OA-related pain, symptom, function in daily living, duration of knee pain, blood pressure, and strength of hip abductor. BMI and waist circumference were associated with sleep duration and eating speed.