C-reactive protein, metabolic syndrome and incidence of severe hip and knee osteoarthritis. A population-based cohort study

Systemic inflammatory biomarkers are novel predictors of all-cause and cardiovascular mortality in individuals with osteoarthritis: a prospective cohort study using data from the NHANES

BACKGROUND

Chronic inflammation may contribute to increased mortality risk in individuals with osteoarthritis (OA), but research on the prognostic value of inflammatory biomarkers is limited. We aimed to evaluate the associations of the systemic immune-inflammation index (SII) and systemic inflammation response index (SIRI) with all-cause and cardiovascular mortality among US adults with OA.

METHODS

This cohort study included 3545 adults with OA aged ≥ 20 years from the National Health and Nutrition Examination Survey 1999-2020. The SII and SIRI were calculated using complete blood cell count data. Participants were categorized as having a higher or lower SII and SIRI using cutoff points derived by the maximally selected rank statistics method. Cox proportional hazards models, Fine-Gray competing risk regression models and time-dependent receiver operating characteristic (ROC) analysis were used to evaluate the associations between the SII/SIRI and mortality in OA patients.

RESULTS

Over a median follow-up of 5.08 (3.42-9.92) years, 636 (17.94%) deaths occurred, including 149 (4.20%) cardiovascular deaths. According to multivariable-adjusted models involving demographic, socioeconomic, and health factors, OA patients with a higher SII had a twofold greater risk of all-cause mortality than patients with a lower SII (HR 2.01; 95% CI: 1.50-2.68). Similarly, a higher SIRI was associated with an 86% increased risk of all-cause mortality relative to a lower SIRI (HR 1.86; 95% CI: 1.46-2.38). Similar to the trend found with all-cause mortality, patients with an elevated SII and SIRI had a 88% and 67% increased risk of cardiovascular mortality, respectively, compared to patients with a lower SII (HR 1.88; 95% CI: 1.16-3.03) and SIRI (HR 1.67; 95% CI: 1.14-2.44). Time-dependent ROC curves showed that both the SII and SIRI have moderate and valid performance in predicting short- and long-term mortality in patients with OA.

CONCLUSIONS

Higher SII and SIRI values were associated with greater all-cause and cardiovascular mortality among US adults with OA.

[Relationship between hypercholesterolemia and osteoarthritis (preliminary results)]

AIM

To evaluate the relationship of hypercholesterolemia (HCE) with clinical, instrumental, and laboratory parameters in osteoarthritis (OA) in a multicenter, cross-sectional study.

MATERIALS AND METHODS

The study included 183 patients aged 40-75 years, with a confirmed diagnosis of stage I-III OA (ACR) of the knee joints, who signed an informed consent. The mean age was 55.6±10.7 years (40 to 75), body mass index was 29.3±6.3 kg/m2, and disease duration was 5 [1; 10] years. For each patient, a case record form was filled out, including anthropometric indicators, medical history, clinical examination data, an assessment of knee joint pain according to VAS, WOMAC, KOOS and comorbidities. All patients underwent standard radiography and ultrasound examination of the knee joints and laboratory tests.

RESULTS

HCE was detected in 59% of patients. Depending on its presence or absence, patients were divided into two groups. Patients were comparable in body mass index, waist and hip measurement, and disease duration but differed significantly in age. Individuals with elevated total cholesterol levels had higher VAS pain scores, total WOMAC and its components, an overall assessment of the patient's health, a worse KOOS index, and ultrasound findings (reduced cartilage tissue). HCE patients showed high levels of cholesterol, low-density lipoproteins, triglycerides, STX-II, and COMP (p<0.05). However, after stratification by age, many initial intergroup differences became insignificant, and differences in the WOMAC pain score persisted.

CONCLUSION

The results of the study confirmed the high prevalence of HCE in OA patients (59%). Patients with OA and increased total cholesterol have more intense pain in the knee joints.

Autophagy in Osteoarthritis: A Double-Edged Sword in Cartilage Aging and Mechanical Stress Response: A Systematic Review

Background: Although osteoarthritis (OA) development is epidemiologically multifactorial, a primary underlying mechanism is still under debate. Understanding the pathophysiology of OA remains challenging. Recently, experts have focused on autophagy as a contributor to OA development. Method: To better understand the pathogenesis of OA, we survey the literature on the role of autophagy and the molecular mechanisms of OA development. To identify relevant studies, we used controlled vocabulary and free text keywords to search the MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, Web of Science, and SCOPUS database. Thirty-one studies were included for data extraction and systematic review. Among these studies, twenty-five studies investigated the effects of autophagy in aging and OA chondrocytes, six studies examined the effects of autophagy in normal human chondrocytes, and only one study investigated the effects of mechanical stress-induced autophagy on the development of OA in normal chondrocytes. Results: The studies suggest that autophagy activation prevents OA by exerting cell-protective effects in normal human chondrocytes. However, in aging and osteoarthritis (OA) chondrocytes, the role of autophagy is intricate, as certain studies indicate that stimulating autophagy in these cells can have a cytotoxic effect, while others propose that it may have a protective (cytoprotective) effect against damage or degeneration. Conclusions: Mechanical stress-induced autophagy is also thought to be involved in the development of OA, but further research is required to identify the precise mechanism. Thus, autophagy contributions should be interpreted with caution in aging and the types of OA cartilage.

Arthritis prevalence is associated with metabolic syndrome risk factors but not with physical activity in middle-aged and older patients - a cross-sectional study

BACKGROUND

In light of the aging population, increasingly suffering from the metabolic syndrome (MS), strategies need to be developed to address global public health challenges known to be associated with MS such as arthritis. As physical activity (PA) may play a crucial role in tackling those challenges, this study aimed to determine the association between the number of MS risk factors, PA and arthritis in people ≥ 50 years old.

METHODS

Data from the Survey of Health, Ageing, and Retirement in Europe (SHARE) were used to estimate the prevalence of arthritis and MS risk factors in the European population ≥ 50 years and to evaluate the associations between MS risk factors, PA and arthritis. Binary logistic regression was performed to calculate the odds ratio of different factors.

RESULTS

73,125 participants were included in the analysis. 55.75% of patients stated at least one of the three MS risk factors. The prevalence of rheumatoid arthritis (RA) and osteoarthritis (OA)/other rheumatism among ≥ 50 years population was 10.19% and 19.32% respectively. Females showed a higher prevalence of arthritis than males. Prevalence did not differ between groups with different levels of PA. Arthritis prevalence was positively correlated with the number of MS risk factors (P < 0.01) but not with PA (P > 0.05).

CONCLUSION

Middle-aged and older Europeans with multiple comorbidities suffered from RA, OA or other rheumatism more frequently than participants with fewer comorbidities, while the level of physical activity was not associated with the number of metabolic risk factors in patients with RA and OA/other rheumatism.

Investigation of the Associations of Smoking With Hip Osteoarthritis: A Baseline Cross-Sectional and Four- to Five-Year Longitudinal Multicohort Study

OBJECTIVE

This study aimed to investigate the effect of smoking on the prevalence, incidence, and progression of hip osteoarthritis (OA). We used data from the Osteoarthritis Initiative (OAI) and the Cohort Hip and Cohort Knee (CHECK) studies.

METHODS

We analyzed 9,386 hips from 4,716 participants (OAI cohort) and 1,954 hips from 977 participants (CHECK cohort). The primary exposure was smoking status at baseline, categorized as current, former, or never smoker. Outcomes of radiographic hip OA (RHOA) and symptomatic hip OA were evaluated both cross-sectionally at baseline and longitudinally over a 4- to 5-year follow-up, with adjustments for major covariates.

RESULTS

No significant differences were observed between current or former smokers and never smokers for any of the outcomes examined, either at baseline or at the 4- to 5-year follow-up. In the cross-sectional analysis, the odds ratios with 95% confidence intervals for the prevalence of RHOA for current and former smokers were 1.29 (0.68-2.46) and 0.99 (0.70-1.40) in the OAI cohort and 1.38 (0.78-2.44) and 0.85 (0.54-1.32) in the CHECK cohort, respectively. In the longitudinal analysis, odds ratio with 95% confidence intervals for the incidence of RHOA were 1.03 (0.23-4.50) and 0.92 (0.46-1.85) in the OAI cohort and 0.61 (0.34-1.11) and 1.00 (0.69-1.44) in the CHECK cohort, respectively.

CONCLUSION

Our study found no clear association between smoking and the prevalence, incidence, or progression of RHOA or symptomatic hip OA, either at baseline or over a 4- to 5-year period.

Beneficial Impact of Eicosapentaenoic Acid on the Adverse Effects Induced by Palmitate and Hyperglycemia on Healthy Rat Chondrocyte

Osteoarthritis (OA) is the most prevalent form of arthritis and a major cause of pain and disability. The pathology of OA involves the whole joint in an inflammatory and degenerative process, especially in articular cartilage. OA may be divided into distinguishable phenotypes including one associated with the metabolic syndrome (MetS) of which dyslipidemia and hyperglycemia have been individually linked to OA. Since their combined role in OA pathogenesis remains to be elucidated, we investigated the chondrocyte response to these metabolic stresses, and determined whether a n-3 polyunsaturated fatty acid (PUFA), i.e., eicosapentaenoic acid (EPA), may preserve chondrocyte functions. Rat chondrocytes were cultured with palmitic acid (PA) and/or EPA in normal or high glucose conditions. The expression of genes encoding proteins found in cartilage matrix (type 2 collagen and aggrecan) or involved in degenerative (metalloproteinases, MMPs) or in inflammatory (cyclooxygenase-2, COX-2 and microsomal prostaglandin E synthase, mPGES) processes was analyzed by qPCR. Prostaglandin E2 (PGE2) release was also evaluated by an enzyme-linked immunosorbent assay. Our data indicated that PA dose-dependently up-regulated the mRNA expression of MMP-3 and -13. PA also induced the expression of COX-2 and mPGES and promoted the synthesis of PGE2. Glucose at high concentrations further increased the chondrocyte response to PA. Interestingly, EPA suppressed the inflammatory effects of PA and glucose, and strongly reduced MMP-13 expression. Among the free fatty acid receptors (FFARs), FFAR4 partly mediated the EPA effects and the activation of FFAR1 markedly reduced the inflammatory effects of PA in high glucose conditions. Our findings demonstrate that dyslipidemia associated with hyperglycemia may contribute to OA pathogenesis and explains why an excess of saturated fatty acids and a low level in n-3 PUFAs may disrupt cartilage homeostasis.

The Significant Role of Alcohol in the Relationship between C-Reactive Protein and Self-Reported Osteoarthritis

BACKGROUND

Despite the known inflammatory nature of osteoarthritis (OA) and the established role of C-reactive protein (CRP) as an inflammation marker, the influence of alcohol consumption on the CRP-OA relationship remains uncertain, with previous research providing conflicting results.

OBJECTIVES

This study aims to examine the potential moderating effect of alcohol on the association between CRP concentrations and self-reported OA.

METHODS

We conducted a cross-sectional study involving 50,259 participants, all data collected from NHANES between 2005-2010 and 2015-2018. A multivariable logistic regression model was used to analyze the relationship between CRP and OA.

RESULTS

We found a nonsignificant positive association between CRP concentration and prevalence of self-reported OA after adjusting for covariates in the raw dataset or 5 multiple imputed datasets. In the stratified analysis by alcohol drinking, for every 10 mg/L higher in CRP concentration, the prevalence of self-reported OA was higher by 13 % in nondrinkers (P = 0.007, adjusted for covariates). Conversely, for every 10 mg/L higher in CRP concentration, the prevalence of self-reported OA was lower by 59 % in drinkers (P = 0.005, adjusted for covariates). Furthermore, we discovered that the directions of the association between CRP concentrations (10 mg/L) and prevalence of self-reported OA [odds ratio (OR) < 1 in the drinking subgroup and OR > 1 in the no-drinking subgroup] were stable in both the main and sensitivity analyses. The significant interaction between CRP concentration and alcohol drinking on the prevalence of self-reported OA was shown in most of our analyses (P-interaction < 0.05).

CONCLUSION

Alcohol consumption may be an interaction factor between CRP and self-reported OA. To our knowledge, our findings are the first to highlight the importance of incorporating analysis of alcohol consumption differences into future studies of CRP and self-reported OA.

Age-related bone diseases: Role of inflammaging

Bone aging is characterized by an imbalance in the physiological and pathological processes of osteogenesis, osteoclastogenesis, adipogenesis, and chondrogenesis, resulting in exacerbated bone loss and the development of age-related bone diseases, including osteoporosis, osteoarthritis, rheumatoid arthritis, and periodontitis. Inflammaging, a novel concept in the field of aging research, pertains to the persistent and gradual escalation of pro-inflammatory reactions during the aging process. This phenomenon is distinguished by its low intensity, systemic nature, absence of symptoms, and potential for management. The mechanisms by which inflammaging contribute to age-related chronic diseases, particularly in the context of age-related bone diseases, remain unclear. The precise manner in which systemic inflammation induces bone aging and consequently contributes to the development of age-related bone diseases has yet to be fully elucidated. This article primarily examines the mechanisms underlying inflammaging and its association with age-related bone diseases, to elucidate the potential mechanisms of inflammaging in age-related bone diseases and offer insights for developing preventive and therapeutic strategies for such conditions.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effectiveness of home-based conventional exercise and cryotherapy on daily living activities in patients with knee osteoarthritis: A randomized controlled clinical trial

BACKGROUND

Knee osteoarthritis (KOA) is a prevalent joint condition associated with aging that causes pain, disability, loss of function, and a decline in quality of life. This study aimed to evaluate the effectiveness of home-based conventional exercise and cryotherapy on daily living activities in patients with KOA.

METHODS

In this randomized controlled clinical trial, the patients who were diagnosed with KOA were assigned to 3 groups: an experimental group (n = 18), the control group 1 (n = 16), and the control group 2 (n = 15). Control and experimental groups engaged in a 2-month home-based exercise (HBE) program. The experimental group received cryotherapy along with HBE. In contrast, the patients in the second control group received regular therapeutic and physiotherapeutic services at the center. The patients were recruited from the Specialized Center for Rheumatic and Medical Rehabilitation in Duhok, Iraq.

RESULTS

The patients in the experimental group had statistically significant better daily activity functions compared to the first and second control groups in pain (2.22 vs 4.81 and 12.7; P < .0001), stiffness (0.39 vs 1.56 and 4.33; P < .0001), physical function (5.72 vs 13.31 and 38.13; P < .0001), and the total score (8.33 vs 19.69 and 55.33; P < .0001) at 2 months. The patients in the experimental and the first control groups had statistically significantly lower balance scores compared to the second control group at 2 months, 8.56 versus 9.30. At 3 months, similar patterns were observed for the daily activity function and balance.

CONCLUSIONS

This study showed that combining HBE and cryotherapy may be an effective technique to improve function among patients with KOA. Cryotherapy could be suggested as a complementary therapy for KOA patients.

The Association of Metabolic Syndrome and Obesity With Clinical Hip Osteoarthritis in the Study of Osteoporotic Fractures and the Osteoporotic Fractures in Men Study Cohorts

OBJECTIVE

Metabolic dysregulation frequently co-occurs with obesity, which has been shown to be a risk factor for lower extremity osteoarthritis (OA). We evaluated the association between metabolic syndrome (MetS), alone and in combination with obesity, and hip OA.

METHODS

In two parallel cross-sectional analyses, we studied 403 women from the Study of Osteoporotic Fractures (SOF) and 2354 men from the Osteoporotic Fractures in Men (MrOS) study. We used multivariable logistic regression to evaluate associations of obesity (body mass index ≥30 kg/m2 ) and/or MetS (three of five National Cholesterol Education Program Adult Treatment Panel III criteria) with clinical hip OA, defined as a modified Croft score of 2 or more or total hip replacement, and pain or limited range of motion. Our analysis adjusted for demographics.

RESULTS

Approximately 3.5% of SOF women and 5.4% of MrOS men had clinical hip OA. Among women, obesity was not associated with hip OA, yet those with MetS had a 365% higher odds of hip OA (95% CI: 1.37-15.83). Among men, those who had obesity had a 115% higher odds of hip OA (95% CI: 1.39-3.32), yet MetS was not associated with hip OA. There was no interaction between MetS, obesity, and hip OA in either women or men.

CONCLUSION

In women, but not in men, MetS was associated with hip OA. In men, but not in women, obesity was associated with hip OA. These findings suggest that mechanical effects of obesity may predominate in the pathogenesis of hip OA in men, whereas metabolic effects predominate in women.

Associations between metabolic factors and radiographic knee osteoarthritis in early disease - a cross-sectional study of individuals with knee pain

Objective

Metabolic factors have been shown to be associated to severe radiographic knee osteoarthritis (RKOA). However, more knowledge is needed in early clinical knee osteoarthritis (KOA). The aim was to study associations between metabolic factors and radiographic knee osteoarthritis (OA) in individuals with knee pain. A second aim was to study associations between metabolic factors and RKOA in those with normal BMI and in those overweight/obese, respectively.

Method

This cross-sectional study included 282 individuals with knee pain (without cruciate ligament injury) and aged 30–67 years, and 70% women. Waist circumference, body mass index (BMI), proportion of fat and visceral fat area (VFA) were assessed. RKOA was defined as Ahlbäck grade 1 in at least one knee. Fasting blood samples were taken and triglycerides, cholesterol (total, low density lipoprotein (LDL) and high density lipoprotein (HDL)), C-reactive protein (CRP), glucose, HbA1C were analysed. Metabolic syndrome was defined in accordance with the International Diabetes Federation (IDF). Associations were analysed by logistic regression.

Results

Individuals with RKOA were older, had higher BMI, higher VFA, larger waist circumference and had increased total cholesterol, triglycerides and LDL-cholesterol, but not fasting glucose. There was no difference between the group with RKOA vs. non-radiographic group regarding the presence of metabolic syndrome. In a subgroup analysis of individuals with normal BMI (n = 126), those with RKOA had higher VFA, more central obesity, higher levels of CRP and total cholesterol, compared with individuals without RKOA. In individuals with obesity, age was the only outcome associated to RKOA.

Conclusion

There were clear associations between metabolic factors and RKOA in individuals with knee pain, also in those with normal BMI. In individuals with obesity age was the only variable associated to RKOA.

Trial registration:

clinicalTrials.gov Identifier: NCT04928170.

Activation of circulating monocytes by low-density lipoprotein-a risk factor for osteoarthritis?

Synovial macrophages are key mediators of OA pathology, and skewing of macrophage phenotype in favour of an M1-like phenotype is thought to underlie the chronicity of synovial inflammation in OA. Components of the metabolic syndrome (MetS), such as dyslipidaemia, can affect macrophage phenotype and function, which could explain the link between MetS and OA development. Recently published studies have provided novel insights into the different origins and heterogeneity of synovial macrophages. Considering these findings, we propose an important role for monocyte-derived macrophages in particular, as opposed to yolk-sac derived residential macrophages, in causing a pro-inflammatory phenotype shift. We will further explain how this can start even prior to synovial infiltration; in the circulation, monocytes can be trained by metabolic factors such as low-density lipoprotein to become extra responsive to chemokines and damage-associated molecular patterns. The concept of innate immune training has been widely studied and implicated in atherosclerosis pathology, but its involvement in OA remains uncharted territory. Finally, we evaluate the implications of these insights for targeted therapy directed to macrophages and metabolic factors.

Fundamentals of OA. An initiative of Osteoarthritis and Cartilage. Obesity and metabolic factors in OA

OBJECTIVE

Obesity was once considered a risk factor for knee osteoarthritis (OA) primarily for biomechanical reasons. Here we provide an additional perspective by discussing how obesity also increases OA risk by altering metabolism and inflammation.

DESIGN

This narrative review is presented in four sections: 1) metabolic syndrome and OA, 2) metabolic biomarkers of OA, 3) evidence for dysregulated chondrocyte metabolism in OA, and 4) metabolic inflammation: joint tissue mediators and mechanisms.

RESULTS

Metabolic syndrome and its components are strongly associated with OA. However, evidence for a causal relationship is context dependent, varying by joint, gender, diagnostic criteria, and demographics, with additional environmental and genetic interactions yet to be fully defined. Importantly, some aspects of the etiology of obesity-induced OA appear to be distinct between men and women, especially regarding the role of adipose tissue. Metabolomic analyses of serum and synovial fluid have identified potential diagnostic biomarkers of knee OA and prognostic biomarkers of disease progression. Connecting these biomarkers to cellular pathophysiology will require future in vivo studies of joint tissue metabolism. Such studies will help reveal when a metabolic process or a metabolite itself is a causal factor in disease progression. Current evidence points towards impaired chondrocyte metabolic homeostasis and metabolic-immune dysregulation as likely factors connecting obesity to the increased risk of OA.

CONCLUSIONS

A deeper understanding of how obesity alters metabolic and inflammatory pathways in synovial joint tissues is expected to provide new therapeutic targets and an improved definition of "metabolic" and "obesity" OA phenotypes.

Comorbidities and Health-Related Quality of Life in Subjects with Spine Osteoarthritis at 50 Years of Age or Older: Data from the Korea National Health and Nutrition Examination Survey

Background and Objective: This study assessed comorbidities and health-related quality of life (HRQOL) in subjects with lumbar spine osteoarthritis (OA) in the Korean population. Materials and Methods: We analyzed 3256 subjects who were 50 years or older and underwent plain radiography of the lumbar spine as part of the Korea National Health and Nutrition Examination Survey (KNHANES) 2012. Radiographic assessment was based on Kellgren–Lawrence (K-L) grade ranging from 0 to 2, with K-L grade 2 defined as lumbar spine OA. HRQOL was assessed by EuroQol-5 dimensions (EQ-5D), which include the EQ-5D index and visual analogue scale (EQ-VAS) measurements. Results: Comorbidities such as hypertension, myocardial infarction, angina, cerebral infarction, and diabetes mellitus were more frequent in spine OA than in controls, while dyslipidemia was less common. Subjects with spine OA had higher mean number of comorbid conditions than controls (1.40 (SE 0.05) vs. 1.20 (SE 0.03), p = 0.001). Subjects with spine OA had much lower EQ-5D index than controls (p < 0.001) but not lower EQ-VAS score. Multivariate binary logistic analysis showed that hypertension and colon cancer were associated with spine OA compared to controls (OR 1.219, 95% CI 1.020–1.456, p = 0.030 and OR 0.200, 95% CI 0.079–0.505, p = 0.001, respectively) after adjustment for confounding factors. Lower EQ-5D index was related to spine OA (95% CI 0.256, 95% CI 0.110–0.595, p = 0.002) but not EQ-VAS score. Conclusion: In this study, we found that comorbidities such as hypertension and colon cancer as well as lower HRQOL were associated with spine OA.

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.

Metabolic obesity and the risk of knee osteoarthritis progression in elderly community residents: A 3-year longitudinal cohort study

OBJECTIVE

Metabolic syndrome is a major health problem worldwide associated with obesity, thus drawing attention to its relation to osteoarthritis (OA). However, it is still uncertain whether metabolic syndrome or body fat distribution is associated with knee OA. The aim of this longitudinal study was to elucidate the association between metabolic obesity and adverse structural changes of knee OA assessed by magnetic resonance imaging (MRI).

METHODS

Participants were recruited from the Hallym Aging Study cohort in Korea. Knee MRI scans, along with dual-energy X-ray absorptiometry, were assessed in 226 participants at baseline and after 3 years. The structural progression in the tibiofemoral joint was evaluated using the semi-quantitative Whole-Organ MRI Score (WORMS) for cartilage morphology and bone marrow lesions (BML). Logistic regression with generalized estimating equation was performed for associations of metabolic risk factors with worsening of WORMS scores at the subregional level.

RESULTS

In the medial compartment, fat mass in women was associated with cartilage loss, but the statistical significance disappeared after adjusting for body mass index. Metabolic syndrome and each of its components were not associated with cartilage loss or increase of BML. On the other hand, the interaction effects of metabolic syndrome on the association between obesity and knee OA progression were not significant.

CONCLUSION

In this cohort, metabolic effects of obesity on knee cartilage damage and BML were not demonstrated. Further large-scale studies are required to prove the causal relationship between metabolic obesity and knee OA.

Associations of Metabolic Syndrome and Its Components with the Risk of Incident Knee Osteoarthritis Leading to Hospitalization: A 32-Year Follow-up Study

OBJECTIVES

To examine whether metabolic syndrome or its individual components predict the risk of incident knee osteoarthritis (OA) in a prospective cohort study during a 32-year follow-up period.

DESIGN

The cohort consisted of 6274 participants of the Mini-Finland Health Survey, who were free from knee OA and insulin-treated diabetes at baseline. Information on the baseline characteristics, including metabolic syndrome components, hypertension, elevated fasting glucose, elevated triglycerides, reduced high-density lipoprotein, and central obesity were collected during a health examination. We drew information on the incidence of clinical knee OA from the national Care Register for Health Care. Of the participants, 459 developed incident knee OA. In our full model, age, gender, body mass index, history of physical workload, smoking history, knee complaint, and previous injury of the knee were entered as potential confounding factors.

RESULTS

Having metabolic syndrome at baseline was not associated with an increased risk of incident knee OA. In the full model, the hazard ratio for incident knee OA for those with metabolic syndrome was 0.76 (95% confidence interval [0.56, 1.01]). The number of metabolic syndrome components or any individual component did not predict an increased risk of knee OA. Of the components, elevated plasma fasting glucose was associated with a reduced risk of incident knee OA (hazard ratio 0.71, 95% confidence interval [0.55, 0.91]).

CONCLUSIONS

Our findings do not support the hypothesis that metabolic syndrome or its components increase the risk of incident knee OA. In fact, elevated fasting glucose levels seemed to predict a reduced risk.

Cholesterol metabolism related genes in osteoarthritis

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

A matrix metalloproteinase-generated neoepitope of CRP can identify knee and multi-joint inflammation in osteoarthritis

OBJECTIVE

To compare C-reactive protein (CRP) and matrix metalloproteinase-generated neoepitope of CRP (CRPM) as biomarkers of inflammation and radiographic severity in patients with knee osteoarthritis.

METHODS

Participants with symptomatic osteoarthritis (n=25) of at least one knee underwent knee radiographic imaging and radionuclide etarfolatide imaging to quantify inflammation of the knees and other appendicular joints. For purposes of statistical analysis, semi-quantitative etarfolatide and radiographic imaging scores were summed across the knees; etarfolatide scores were also summed across all joints to provide a multi-joint synovitis measure. Multiple inflammation and collagen-related biomarkers were measured by ELISA including CRP, CRPM, MMP-generated neoepitopes of type I collagen and type III collagen in serum (n=25), and CD163 in serum (n=25) and synovial fluid (n=18).

RESULTS

BMI was associated with CRP (p=0.001), but not CRPM (p=0.753). Adjusting for BMI, CRP was associated with radiographic knee osteophyte score (p=0.002), while CRPM was associated with synovitis of the knee (p=0.017), synovitis of multiple joints (p=0.008), and macrophage marker CD163 in serum (p=0.009) and synovial fluid (p=0.03). CRP correlated with MMP-generated neoepitope of type I collagen in serum (p=0.045), and CRPM correlated with MMP-generated neoepitope of type III collagen in serum (p<0.0001). No biomarkers correlated with age, knee pain, or WOMAC pain.

CONCLUSIONS

To our knowledge, this is the first time that CRPM has been shown to be associated with knee and multi-joint inflammation based on objective imaging (etarfolatide) and biomarker (CD163) measures. These results demonstrate the capability of biomarker measurements to reflect complex biological processes and for neoepitope markers to more distinctly reflect acute processes than their precursor proteins. CRPM is a promising biomarker of local and systemic inflammation in knee OA that is associated with cartilage degradation and is independent of BMI. CRPM is a potential molecular biomarker alternative to etarfolatide imaging for quantitative assessment of joint inflammation.

Nutritional Status and Health-Related Quality of Life among Knee and Hip Osteoarthritis Patients under Rehabilitation Care in Kuala Nerus, Terengganu, Malaysia

Introduction:

The World Health Organisation (WHO) has estimated that 80% of people with osteoarthritis (OA) have movement limitations while 25% of them cannot perform their major daily activities, thus resulting in a decline of their nutritional status and quality of life (QOL). Therefore, this study aimed to compare the nutritional status and health-related quality of life (HRQOL) of OA patients between gender and age group.

Material and Methods:

A cross-sectional study was conducted on 131 OA patients in Rehabilitation Health Organisation, Terengganu. Socio-demographic, clinical, lifestyle histories, 24-hour dietary intake and HRQOL were assessed using a structured questionnaire.

Results:

Knee and/or hip OA patients recruited consisted of 19.1% of men and 80.9 % of women collectively with a mean age of 61.81 (9.28) years ranging from 38 to 83 years. The percentages of underweight, normal, overweight, and obese patients were 1.5%, 12.2%, 36.7%, and 49.6%, respectively. Further assessment of HRQOL showed that the highest mean score was obtained by the social functioning (SF) domain of 41.25 (27.16), while the mental domain scored the least mean score of 21.15 (20.92). In terms of gender breakdown, the males had significantly greater weight and height but lower body fat (BF) compared to their female counterparts, as well as a significantly higher energy, carbohydrate and protein intake. According to the age group, patients aged < 60 years had significantly greater weight, height, and BF than those aged ≥ 60 years.

Conclusion:

This study is an important baseline reference for proper OA management and prevention by providing crucial nutritional status and HRQOL information.

Association between metabolic associated fatty liver disease and osteoarthritis using data from the Korean national health and nutrition examination survey (KNHANES)

Osteoarthritis of the knee (knee OA) is on the rise due to the aging population and increasing obesity. In addition to mechanical stress attributed to weight and age, osteoarthritis is associated with obesity and metabolic dysregulation. Here, a cross-sectional study targeting retrospectively registered 17,476 adults aged 50 years or older who were enrolled in the National Health and Nutrition Survey (2010-2011) was performed to analyze the association between the newly named metabolic associated fatty liver disease (MAFLD) and knee OA. Fatty liver index (FLI) ≥ 60 confirmed the presence of MAFLD, and FLI < 30 indicated the absence of MAFLD. Knee OA was diagnosed according to the Kellgren-Lawrence scale based on knee radiography results. A complex sample logistic regression analysis was performed. Statistically significant factors were adjusted to estimate probability ratios, and 95% confidence intervals were used to investigate the association between knee OA and MAFLD. The probability of knee OA was 1.479 times higher in the presence of MAFLD than that in the normal group. The results indicate that MAFLD is significantly associated with knee OA, suggesting that these two disorders should be managed simultaneously.

Multidisciplinary Intervention Before Joint Replacement Surgery May Improve Outcomes for People with Osteoarthritis and Metabolic Syndrome: A Cohort Study

Background: Metabolic syndrome has been associated with poorer outcomes in the immediate postoperative period following joint replacement surgery for osteoarthritis. The aim of this study was to determine whether a multidisciplinary, preoperative intervention would minimize postoperative differences between people with and without metabolic syndrome who underwent joint replacement surgery for osteoarthritis. Method: A retrospective cohort study of older adults with multiple comorbidities (n = 230) attending a preoperative intervention service before lower limb joint replacement surgery. The intervention aimed to optimize the patient's health and functional reserve before surgery through weight loss, physical activity and medical management. Patient outcomes were adverse events, discharge destination and function. Health service outcomes were length of stay, hospital readmissions and emergency department presentations over a 2-year follow-up. Results: Two-thirds of participants (n = 151) had metabolic syndrome. There were no significant differences between those with and without metabolic syndrome in terms of discharge destination or adverse events during the acute hospital admission. There were no differences in function during rehabilitation but people with metabolic syndrome had significantly more adverse events (P = 0.037) during rehabilitation. In the 2 years following surgery, there were no differences in hospital readmission rates but people with metabolic syndrome had a higher observed frequency of potentially avoidable emergency department presentations (P = 0.066). Conclusions: Providing a preoperative intervention may help minimize differences between people with and without metabolic syndrome in the immediate postoperative period. However, having a diagnosis of metabolic syndrome may still adversely affect some long-term health service outcomes following joint replacement surgery.

Obesity Is Preferentially Associated With Patellofemoral Compartment Wear: A Magnetic Resonance Imaging Assessment

BACKGROUND

A well-known association exists between obesity and knee osteoarthritis (OA) for both incidence and progression of the disease. However, the cartilage wear patterns in OA associated with obesity are less well studied.

METHODS

The OA initiative, a prospective sample of 4,796 patients, was used for this study. After the application of inclusion and exclusion criteria, patients were stratified into increasing body mass index (BMI) cohorts (BMI < 25, 25 ≤ BMI < 30, 30 ≤ BMI < 40, and 40 ≤ BMI). Knee MRIs were assessed using the semiquantitative MRI Osteoarthritis Knee Score scores. Patellofemoral (PF), medial, and lateral compartment cartilage scores were compared among BMI cohorts, controlling for confounders using linear regression models.

RESULTS

In total, 2,006 patients were present in our cohort, 773 men (38.5%) and 1,233 women (61.5%); the mean age was 61.7 ± 8.9 years. Increasing BMI was independently associated with increasing grades of PF wear for both right and left knees in the lateral patella facet (right knee β: 0.208, 95% confidence interval [CI]: 0.128 to 0.288, P < 0.001, left knee β: 0.147, 95% CI: 0.056 to 0.237, P = 0.002), medial femoral trochlea (right knee β: 0.135, 95% CI: 0.065 to 0.204, P < 0.001, left knee β: 0.142, 95% CI: 0.063 to 0.221, P < 0.001), and lateral femoral trochlea (right knee β: 0.163, 95% CI: 0.093 to 0.232, P < 0.001, left knee β: 0.147, 95% CI: 0.067 to 0.226, P < 0.001). For the right knee, increasing BMI was associated with medial compartment wear in the posterior femoral area (β: 0.070, 95% CI: 0.015 to 0.126, P = 0.013) and lateral compartment wear in the central tibial area (β: 0.070, 95% CI: 0.002 to 0.138, P = 0.045). For the left knee, increasing BMI was associated with medial compartment wear in the central femoral area (β: 0.093, 95% CI: 0.016 to 0.171, P = 0.018).

DISCUSSION

Obesity is preferentially associated with increasing cartilage wear in the PF compartment in comparison to the tibiofemoral compartment. Physical therapy and exercise programs that promote weight loss should be modified to decrease forces on the PF joint.

Diabetes mellitus is not a risk factor for osteoarthritis

BACKGROUND

Association between diabetes mellitus (DM) and risk of osteoarthritis (OA) can be confounded by body mass index (BMI), a strong risk factor for both conditions. We evaluate the association between DM or hyperglycaemia with OA using systematic review and meta-analysis.

METHODS

We searched PubMed and Web of Science databases in English for studies that gave information on the association between DM and OA. Two meta-analysis models were conducted to address: (1) risk of DM comparing subjects with and without OA and (2) risk of OA comparing subjects with and without DM. As far as available, risk estimates that adjusted for BMI were used.

RESULTS

31 studies with a pooled population size of 295 100 subjects were reviewed. 16 and 15 studies reported positive associations and null/ negative associations between DM and OA. 68.8% of positive studies had adjusted for BMI, compared with 93.3% of null/negative studies. In meta-analysis model 1, there was an increase prevalence of DM in subjects with OA compared with those without (OR 1.56, 95% CI 1.28 to 1.89). In meta-analysis model 2, there was no increased risk of OA (OR 1.14, 95% CI 0.98 to 1.33) in subjects with DM compared with those without, regardless of gender and OA sites. Comparing subjects with DM to those without, an increased risk of OA was noted in cross-sectional studies, but not in case-control and prospective cohort studies.

CONCLUSIONS

This meta-analysis does not support DM as an independent risk factor for OA. BMI was probably the most important confounding factor.

The association of the progression of knee osteoarthritis with high-sensitivity CRP in community-dwelling people-the Yakumo study

OBJECTIVE

We aimed to investigate the relationship between high-sensitivity CRP (hs-CRP) levels and the knee osteoarthritis (KOA) status and whether high hs-CRP levels predict the progression of clinical KOA in community-dwelling people.

METHODS

We enrolled 247 subjects (male, n = 99; female, n = 148) who participated in the "Yakumo study" at least twice from 2003 to 2008. The KOA was evaluated by knee X-ray using the knee osteoarthritis computer-aided diagnosis (KOACAD) measurement system to obtain the mJSW, the size of the osteophyte area (OPA), and femorotibial angle (FTA). The pain intensity of the knee joint was measured using a visual analog scale (VAS, 0-100). First, we performed a multiple regression analysis to assess the relationship between the initial hs-CRP and mJSW, OPA, FTA, and VAS. Second, we examined the correlated coefficients between the amount of change hs-CRP and radiographic progressions and VAS changes. Third, we divided into two groups. Group H elevated hs-CRP levels (> 0.1 mg/dl). We picked up the subject matched to Group H according to BMI, age, sex, and medial mJSW at baseline in a 1:1 ratio; these participants were classified as the control group (Group L). The Mann-Whitney U test was used to compare the demographic data between the two groups. P values of < 0.05 were considered to indicate statistical significance.

RESULTS

The initial hs-CRP was a significant explanatory factor for mJSW and VAS change in multiple regression analysis. The change of VAS value negatively correlated with the change of hs-CRP. Besides, the change of hs-CRP did not correlate with the radiographical change. Among these subjects, 55 had elevated hs-CRP levels (> 0.1 mg/dl) (Group H). Among the 192 subjects whose hs-CRP levels were ≤ 0.1 mg/dl, 55 subjects were matched to patients in Group H according to the age, sex, BMI, and average minimum joint space width (mJSW) at baseline and were used as a control group (Group L). The narrowing of the medial mJSW and the amount of change in OPA in group H were significantly greater than group L. The amount of change in FTA and VAS scores did not differ between the two groups.

CONCLUSION

Hs-CRP levels would be significantly associated with the progression of knee osteoarthritis. Key Points • We investigated the relationship between hs-CRP levels and the progression and the pain of osteoarthritis knee. • We used a KOACAD system, which can measure the medial and lateral joint space narrowing, osteophyte, and femoral-tibia angle from plain radiographs automatically. • Hs-CRP levels were significantly associated with the progression of knee osteoarthritis.

Obese and overweight individuals have greater knee synovial inflammation and associated structural and cartilage compositional degeneration: data from the osteoarthritis initiative

OBJECTIVE

This work aims to study (i) the relationship between body mass index (BMI) and knee synovial inflammation using non-contrast-enhanced MRI and (ii) the association of synovial inflammation versus degenerative abnormalities and pain.

MATERIALS AND METHODS

Subjects with risk for and mild to moderate radiographic osteoarthritis were selected from the Osteoarthritis Initiative. Subjects were grouped into three BMI categories with 87 subjects per group: normal weight (BMI, 20-24.9 kg/m²), overweight (BMI, 25-29.9 kg/m²), and obese (BMI, ≥ 30 kg/m²), frequency matched for age, sex, race, Kellgren-Lawrence grade, and history of knee surgery and injury. Semi-quantitative synovial inflammation imaging biomarkers were obtained including effusion-synovitis, size and intensity of infrapatellar fat pad signal abnormality, and synovial proliferation score. Cartilage composition was measured using T₂ relaxation time and structural abnormalities using the whole-organ magnetic resonance imaging score (WORMS). The Western Ontario and McMasters (WOMAC) Osteoarthritis Index was used for pain assessment. Intra- and inter-reader reproducibility was assessed by kappa values.

RESULTS

Overweight and obese groups had higher prevalence and severity of all synovial inflammatory markers (p ≤ 0.03). Positive associations were found between synovial inflammation imaging biomarkers and average T₂ values, WORMS maximum scores and total WOMAC pain scores (p < 0.05). Intra- and inter-reader kappa values for imaging biomarkers were high (0.76-1.00 and 0.60-0.94, respectively).

CONCLUSION

Being overweight or obese was significantly associated with a greater prevalence and severity of synovial inflammation imaging biomarkers. Substantial reproducibility and high correlation with knee structural, cartilage compositional degeneration, and WOMAC pain scores validate the synovial inflammation biomarkers used in this study.

Metabolic syndrome and the incidence of knee osteoarthritis: A meta-analysis of prospective cohort studies

Background

Cross-sectional studies suggest an association between metabolic syndrome (MetS) and knee osteoarthritis (KOA). We performed a meta-analysis to evaluate whether MetS is an independent risk factor for KOA.

Methods

Prospective cohort studies evaluating the association between MetS and KOA in general population were retrieved from PubMed and Embase. Only studies with multivariate analyses were included. Data were pooled with a random-effect model, which is considered to incorporate heterogeneity among the included studies.

Results

Five studies including 94,965 participants were included, with 18,990 people with MetS (20.0%). With a mean follow-up duration of 14.5 years, 2,447 KOA cases occurred. Pooled results showed that MetS was not significant associated with an increased risk of KOA after controlling of factors including body mass index (adjusted risk ratio [RR]: 1.06, 95% CI: 0.92~1.23, p = 0.40; I² = 33%). Subgroup analysis showed that MetS was independently associated with an increased risk of severe KOA that needed total knee arthroplasty (RR = 1.16, 95% CI: 1.03~1.30, p = 0.02), but not total symptomatic KOA (RR = 0.84, 95% CI: 0.65~1.08, p = 0.18). Stratified analyses suggested that MetS was independently associated with an increased risk of KOA in women (RR = 1.23, 95% CI: 1.03~1.47, p = 0.02), but not in men (RR = 0.90, 95% CI: 0.70~1.14, p = 0.37).

Conclusions

Current evidence from prospective cohort studies did not support MetS was an independent risk factor of overall KOA in general population. However, MetS may be associated with an increased risk of severe KOA in general population, or overall KOA risk in women.

Association between statin use and incidence or progression of osteoarthritis: meta-analysis of observational studies

OBJECTIVE

The objective of the study was to determine whether statin use could reduce the risk of the incidence or progression of osteoarthritis (OA).

METHODS

The PubMed, Embase, and Cochrane databases were systematically searched for observational studies on the association between statin use and OA. ORs and 95% CIs were directly retrieved or calculated. The Newcastle-Ottawa quality assessment scale was used for study quality assessment. Subgroup analysis, sensitivity analysis, and publication bias were conducted using Stata software.

RESULTS

A total of 11 studies (679807 participants) were identified from the systematic literature search. No significant association between statin use and incidence (OR = 1.010; 95% CI: 0.968 to 1.055; P = 0.638) or progression (OR = 1.076; 95% CI: 0.824 to 1.405; P = 0.589) of OA was found in our meta-analysis. The meta-analysis according to the symptomatic or radiological OA also found no significant association between statin use and OA. The subgroup analysis showed that atorvastatin (OR = 0.953; 95% CI: 0.911 to 0.998; P = 0.041) and rosuvastatin (OR = 1.180; 95% CI: 1.122 to 1.241; P < 0.0001) had opposite effects on OA. The results of the analysis according to the joint site, interval, and statin dose were all not significant.

CONCLUSIONS

Statin use may not be associated with a lower risk of incidence and progression of OA, regardless of joint site. The opposite effects of atorvastatin and rosuvastatin were detected in OA.

Metabolic syndrome, hypertension, and hyperglycemia were positively associated with knee osteoarthritis, while dyslipidemia showed no association with knee osteoarthritis

OBJECTIVE

Metabolic syndrome (MetS) is a clustering of at least three of the following four medical conditions: obesity, hypertension, dyslipidemia, and hyperglycemia. We aimed to discover the relationships between these diseases and osteoarthritis (OA) of the knee.

METHODS

We searched four databases (EMBASE, PubMed, Cochrane Library, and MEDLINE), as well as articles on websites and conference materials. Study effect estimates and their 95% confidence intervals (CIs) were extracted and calculated. Sensitivity analyses were undertaken to determine inter-study heterogeneity. Finally, we tested for publication bias to determine whether the outcome of the meta-analysis was robust.

RESULTS

A total of 1609 articles were identified, 40 of which were included. In radiological studies, the relationships with OA were increased for people with the following diseases: metabolic syndrome (OR 1.418, 95% CI 1.162 to 1.730), hypertension (OR 1.701, 95% CI 1.411 to 2.052), and hyperglycemia (OR 1.225, 95% CI 1.054 to 1.424). In symptomatic studies, the outcomes were similar in metabolic syndrome (OR 1.174, 95% CI 1.034 to 1.332) and hypertension (OR 1.324, 95% CI 1.186 to 1.478) studies, while there were no associations in hyperglycemia (OR 0.975, 95% CI 0.860 to 1.106) studies. There was no correlation between dyslipidemia and OA, whether in radiological studies (OR 1.216, 95% CI 0.968 to 1.529) or symptomatic studies (OR 1.050, 95% CI 0.961 to 1.146).

CONCLUSIONS

In both studies, metabolic syndrome and hypertension were positively associated with knee OA, and dyslipidemia showed no correlations. Hyperglycemia was associated with OA in radiological studies, while results were reversed in symptomatic studies. Key Points • The hypothesis that metabolic syndrome and its components increase the risk for knee osteoarthritis is attractive; thus, this meta-analysis may help us find out the answer. • There were lots of large-scale studies here, and the total participants were considerable; and this meta-analysis was relatively robust because of reasonable heterogeneity and publication bias. • Targeted education and effective management of risk factors may be helpful for reducing the prevalence of knee osteoarthritis.

Dyslipidemia Might Be Associated with an Increased Risk of Osteoarthritis

Background

According to several studies, the autoimmune response may lead to osteoarthritis and dyslipidemia and may affect the homeostasis of the human body's internal environment and then cause its own immune regulation. Consequently, the risk of osteoarthritis might be increased by dyslipidemia, but this association is not universally acknowledged. Therefore, a systematic review and meta-analysis was conducted to study the relationship between dyslipidemia and the risk of osteoarthritis.

Methods

In this study, PubMed, EMBASE, and the ISI Web of Science were used to identify related studies published before July 2018. The relationship between dyslipidemia and the risk of osteoarthritis was evaluated on the basis of relative risk (RR) values and the corresponding 95% confidence intervals (CIs). To further investigate this relationship, we also employed the random effects model proposed by DerSimonian and Laird.

Results

A total of nine studies were included to study the effect of dyslipidemia on the risk of osteoarthritis, including four cohort, three case-control, and two cross-sectional studies. Among these studies, six stated data for knee osteoarthritis, two reported on hand osteoarthritis, and one reported on hip osteoarthritis. A total of 53,955 participants were included in the meta-analysis, comprising 22,501 patients with OA (19,733 hand OA, 2,679 knee OA, and 89 hip OA). Based on the meta-analysis of case-control and cross-sectional studies, osteoarthritis was clearly higher in those with dyslipidemia compared to those who did not suffer from dyslipidemia (case-control: OR = 1.37; 95%CI = 1.27–1.46; cross-sectional: OR = 1.33; 95%CI = 1.21-1.46). In addition, the meta-analysis of cohort studies did not present any relationship between dyslipidemia and OA (RR = 1.00; 95%CI = 0.85–1.14).

Conclusions

Even though our meta-analysis of case-control and cross-sectional studies suggested a strong relationship between dyslipidemia and osteoarthritis; this relationship was not validated by our meta-analysis of only cohort studies. As a result, further investigation needs to be conducted on the relationship between dyslipidemia and osteoarthritis, considering the significant public health relevance of the topic.

Bidirectional association between metabolic syndrome and osteoarthritis: a meta-analysis of observational studies

BACKGROUND

Emerging observational studies suggest an association between metabolic syndrome (MetS) and osteoarthritis (OA). This meta-analysis was conducted to examine whether or not there is a bidirectional relationship between MetS and OA.

METHODS

The PubMed and Embase databases were searched from their inception to October 2019. We selected studies according to predefined criteria. Random effects were selected to calculate two sets of pooled risk estimates: MetS predicting OA and OA predicting MetS.

RESULTS

A total of seven cross-sectional studies and four cohort studies met the criteria for MetS predicting the onset of OA. Another six cross-sectional studies and one cohort study met the criteria for OA predicting the onset of MetS. The pooled odds risk (OR) for OA incidences associated with baseline MetS was 1.45 (95% CI 1.27-1.66). The OR for MetS incidences associated with baseline OA was 1.90 (95% CI 1.11-3.27). In an overall analysis, we found that MetS was associated with prevalent OA in both cross-sectional studies (OR = 1.32, 95% CI 1.21-1.44) and cohort studies (OR = 1.76, 95% CI 1.29-2.42). No indication of heterogeneity was found in the cross-sectional studies (p = 0.395, I² = 4.8%), whereas substantial heterogeneity was detected in the cohort studies (p = 0.000, I² = 79.3%).

CONCLUSION

Meta-analysis indicated a bidirectional association between MetS and OA. We advise that patients with MetS should monitor their OA status early and carefully, and vice versa.

Metabolic Score for Insulin Resistance Is Correlated to Adipokine Disorder and Inflammatory Activity in Female Knee Osteoarthritis Patients in a Chinese Population

PURPOSE

This study was to evaluate the metabolic score for insulin resistance (METS-IR) in female knee osteoarthritis (KOA) patients in a Chinese population. The associations between METS-IR and adipokines, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) were investigated.

PATIENTS AND METHODS

This study included 4686 women from the 2011 China Health and Retirement Longitudinal Study (CHARLS) and 108 women who underwent arthroplasty of KOA at a university hospital. The clinical data were collected, and adipokines were evaluated. METS-IR was calculated in the KOA patients and compared with the national baseline. Logistic regression analyses were applied to explore the associations of METS-IR with adipokines, ESR, and CRP.

RESULTS

Receiver operating characteristic curve analysis of METS-IR and metabolic syndrome (MetS) in national baseline showed an area under the curve value of 0.851, with sensitivity of 0.777 and specificity of 0.772. The METS-IR of KOA was higher than the national baseline level (40.29 ± 6.98 vs 36.20 ± 8.50, P < 0.01), even after adjusting age. In addition, the METS-IR was higher in patients with KOA who had MetS than in those without metabolic syndrome (nMetS), even after adjusting body mass index (BMI). After adjusting for age and BMI, METS-IR was associated with CRP (OR 1.238, 95% confidence interval (CI) 1.088, 1.409, P < 0.01), ESR (OR 1.124, 95% CI 1.008, 1.254, P = 0.036), plasma leptin (OR 1.123, 95% CI 1.052, 1.199, P < 0.01), plasma resistin (OR 1.134, 95% CI 1.011, 1.271, P = 0.031), and plasma adiponectin (OR 0.865, 95% CI 0.771, 0.971, P = 0.014).

CONCLUSION

METS-IR in female KOA was higher than that of the national baseline. The METS-IR was related to adipokine disorder and inflammatory activity. These findings suggest that METS-IR can be used to evaluate the degree of involvement of MetS in KOA.

Association of Diabetes Mellitus and Biomarkers of Abnormal Glucose Metabolism With Incident Radiographic Knee Osteoarthritis

OBJECTIVE

The association of diabetes mellitus (DM) with increased risk of knee osteoarthritis (OA) is uncertain. We evaluated associations of DM and biomarkers of abnormal glucose metabolism with incident radiographic knee OA, controlling for body mass index (BMI).

METHODS

Participants (mean ± SD age 60.6 ± 7.8 years; mean ± SD body mass index [BMI] 29.1 ± 4.9 kg/m2 ) were from the Multicenter Osteoarthritis Study and did not have radiographic knee OA at baseline (Kellgren/Lawrence [K/L] grade <2 bilaterally). A random sample (n = 987) was selected and stratified by BMI. Baseline serum fasting glucose and homeostasis model assessment-estimated insulin resistance (HOMA-IR) were measured. Participants were categorized as having DM based on self-report, use of medication, or fasting glucose ≥126 mg/dl. Incident radiographic knee OA (K/L grade ≥2 or knee replacement) was assessed at 3 follow-up visits (30, 60, and 84 months). Knee-level pooled logistic regression analysis was performed to obtain odds ratios (ORs) (95% confidence interval [95% CI]) for associations of DM status and biomarkers of abnormal glucose metabolism with incident radiographic knee OA.

RESULTS

After adjustment for BMI, the odds of incident radiographic knee OA were not associated with baseline DM status nor with levels of fasting glucose and HOMA-IR, overall and in men. In women, HOMA-IR was inversely associated with odds of incident radiographic knee OA (adjusted OR 0.80 [95% CI 0.69-0.94], P = 0.005).

CONCLUSION

DM and higher levels of biomarkers of abnormal glucose metabolism were not associated with increased odds of incident radiographic knee OA after adjusting for BMI in this cohort overall. A possible protective association of higher HOMA-IR with incident radiographic knee OA in women warrants further investigation.

Role of Magnetic Resonance Imaging in Classifying Individuals Who Will Develop Accelerated Radiographic Knee Osteoarthritis

We assessed whether adding magnetic resonance (MR)-based features to a base model of clinically accessible participant characteristics (i.e., serological, radiographic, demographic, symptoms, and physical function) improved classification of adults who developed accelerated radiographic knee osteoarthritis (AKOA) or not over the subsequent 4 years. We conducted a case-control study using radiographs from baseline and the first four annual visits of the osteoarthritis initiative to define groups. Eligible individuals had no radiographic KOA in either knee at baseline (Kellgren-Lawrence [KL] grade <2). We classified two groups matched on sex (i) AKOA: at least one knee developed advanced-stage KOA (KL = 3 or 4) within 48 months and (ii) did not develop AKOA within 48 months. The MR-based features were assessments of bone, effusion/synovitis, tendons, ligaments, cartilage, and menisci. All characteristics and MR-based features were from the baseline visit. Classification and regression tree analyses were performed to determine classification rules and identify statistically important variables. The CART models with and without MR features each explained approximately 40% of the variability. Adding MR-based features to the model yielded modest improvements in specificity (0.90 vs. 0.82) but lower sensitivity (0.62 vs. 0.70) than the base model. There was consistent evidence that serum glucose, effusion-synovitis volume, and cruciate ligament degeneration are statistically important variables in classifying individuals who will develop AKOA. We found common MR-based measures failed to dramatically improve classification. These findings also show a complex interplay among participant characteristics and a need to identify novel characteristics to improve classification. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2420-2428, 2019.

Causal Factors for Knee, Hip, and Hand Osteoarthritis: A Mendelian Randomization Study in the UK Biobank

OBJECTIVE

There is no curative treatment for osteoarthritis (OA), which is the most common form of arthritis. This study was undertaken to identify causal risk factors of knee, hip, and hand OA.

METHODS

Individual-level data from 384,838 unrelated participants in the UK Biobank study were analyzed. Mendelian randomization (MR) analyses were performed to test for causality for body mass index (BMI), bone mineral density (BMD), serum high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglyceride levels, type 2 diabetes, systolic blood pressure (BP), and C-reactive protein (CRP) levels. The primary outcome measure was OA determined using hospital diagnoses (all sites, n = 48,431; knee, n = 19,727; hip, n = 11,875; hand, n = 2,330). Odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated.

RESULTS

MR analyses demonstrated a robust causal association of genetically determined BMI with all OA (OR per SD increase 1.57 [95% CI 1.44-1.71]), and with knee OA and hip OA, but not with hand OA. Increased genetically determined femoral neck BMD was causally associated with all OA (OR per SD increase 1.14 [95% CI 1.06-1.22]), knee OA, and hip OA. Low systolic BP was causally associated with all OA (OR per SD decrease 1.55 [95% CI 1.29-1.87]), knee OA, and hip OA. There was no evidence of causality for the other tested metabolic factors or CRP level.

CONCLUSION

Our findings indicate that BMI exerts a major causal effect on the risk of OA at weight-bearing joints, but not at the hand. Evidence of causality of all OA, knee OA, and hip OA was also observed for high femoral neck BMD and low systolic BP. However, we found no evidence of causality for other metabolic factors or CRP level.

Possible association between circulating CTRP3 and knee osteoarthritis in postmenopausal women

BACKGROUND

Osteoarthritis (OA) is considered as one of the most common cause of chronic pain and functional disabilities in the elderly.

AIM

To examine serum levels of complement-C1q TNF-related protein 3 (CTRP3) in postmenopausal women with knee OA.

METHODS

A population-based cross-sectional study was performed in women who complained of chronic knee pain. All subjects were followed by clinical and weight-bearing bilateral anteroposterior radiographical examinations. The Kellgren and Lawrence (K&L) score was used for knee OA classification. Two groups of postmenopausal women were chosen to investigate CTRP3 as an OA marker who had the K&L score ≥ 3 as a case group and K&L ≤ 1 as a control group. Serum levels of CTRP3 were measured in two groups.

RESULTS

According to K&L classification, 36 subjects with knee OA and 54 age-matched without or mild OA were selected. After adjusting the obtained data for taking NSAID drugs, the concentration of Ln CTRP3 in serum of patients with OA was lower compared to control group [mean ± SE, (0.39 ± 0.05 ng/ml vs. 0.48 ± 0.03 ng/ml, respectively, p = 0.04)].

DISCUSSION

There is a possible role for CTRP3 as an anti-inflammatory mediator in knee OA in postmenopausal women.

CONCLUSIONS

Our results indicate an association between CTRP3 and knee OA. However, a much more robust study is required to draw that circulating CTRP3 could be a clinical marker for osteoarthritis.

What Is the Evidence to Support the Association Between Metabolic Syndrome and Osteoarthritis? A Systematic Review

OBJECTIVE

There is conflicting evidence on the association between metabolic syndrome (MetS) with the risk of osteoarthritis (OA). We aimed to systematically summarize the empirical evidence and discuss challenges in research methodologies in addressing this question.

METHODS

We performed a systematic literature review based on PubMed, Embase, Web of Science, and the Cochrane Database of Systematic Reviews on published epidemiologic studies that examined the association between MetS and the risk of OA. We included cross-sectional studies, case-control studies, and cohort studies with appropriate covariate adjustments. We extracted information on prevalence, incidence, crude and adjusted effect estimates, and the 95% confidence intervals from the articles, or this information was provided by the authors. We listed the main methodologic issues existing in current literature and provided recommendations for future research on this topic.

RESULTS

We identified 7 eligible studies on knee OA, 3 on hip OA, and 3 on hand OA. In studies that adjusted for body mass index or weight, MetS was not significantly associated with the risk of knee OA. No significant associations were reported for hip OA. For hand OA, the data were sparse and insufficient to reach a conclusion. Studies were mostly cross-sectional, exposure included only 1 time measurement, few studies had incident outcomes, and covariate adjustment was often insufficient.

CONCLUSION

Our review was unable to reach a definitive conclusion due to insufficient data, although the data suggest that knee and hip OA are not associated with MetS. Future longitudinal studies with incident OA cases, repeated measurement of MetS, and appropriate covariate adjustment are needed.

Vascular cell adhesion molecule 1 in patients with severe osteoarthritis of the hip : A prospective cross-sectional study

BACKGROUND

Osteoarthritis (OA) of the hip is a frequent and debilitating joint disease. Only few clinical risk factors for hip OA are established and clinically applicable biomarkers to identify patients at risk are still lacking. The glycoprotein vascular cell adhesion molecule 1 (VCAM-1) is expressed by chondrocytes and synovial tissue and was a predictive marker for development of severe large joint OA in a previous study.

OBJECTIVE

It was tested whether increased serum levels of VCAM-1 are prevalent in patients with severe OA of the hips.

METHODS

In this prospective, multicenter, cross-sectional study, risk factors of severe hip OA were investigated in patients scheduled for hip joint arthroplasty and 100 patients were randomly selected for validation of VCAM-1 as a potential biomarker for hip OA. Serum samples were analyzed by an enzyme-linked immunosorbent assay and compared with a sex and age-matched control cohort.

RESULTS

The groups were similar in age, gender ratio and prevalence of diabetes. Serum concentrations of VCAM-1 were 8% higher in OA patients compared to controls, without reaching statistical significance (818 ng ml^-1, 95% confidence interval, CI 746-891 ng ml^-1 versus 759 ng m^-1, 95% CI 711-807 ng ml^-1; P = 0.4839).

CONCLUSION

The results of this study show that serum concentrations of VCAM-1 cannot distinguish patients with severe hip OA from age and sex-matched controls.

Cardiometabolic Polygenic Risk Scores and Osteoarthritis Outcomes: A Mendelian Randomization Study Using Data From the Malmö Diet and Cancer Study and the UK Biobank

Objective

To investigate the causal role of cardiometabolic risk factors in osteoarthritis (OA) using associated genetic variants.

Methods

We studied 27,691 adults from the Malmö Diet and Cancer Study (MDCS) and replicated novel findings among 376,435 adults from the UK Biobank. Trait‐specific polygenic risk scores for low‐density lipoprotein (LDL) and high‐density lipoprotein (HDL) cholesterol levels, triglyceride levels, body mass index (BMI), fasting plasma glucose (FPG) levels, and systolic blood pressure (BP) were used to test the associations of genetically predicted elevations in each trait with incident OA diagnosis (n = 3,559), OA joint replacement (n = 2,780), or both (total OA; n = 4,226) in Mendelian randomization (MR) analyses in the MDCS, and with self‐reported and/or hospital‐diagnosed OA (n = 65,213) in the UK Biobank. Multivariable MR, MR‐Egger, and weighted median MR were used to adjust for potential pleiotropic biases.

Results

In the MDCS, genetically predicted elevation in LDL cholesterol level was associated with a lower risk of OA diagnosis (odds ratio [OR] 0.83 [95% confidence interval (95% CI) 0.73–0.95] per 1SD increase) and total OA (OR 0.87 [95% CI 0.78–0.98]), which was supported by multivariable MR for OA diagnosis (OR 0.84 [95% CI 0.75–0.95]) and total OA (0.87 [95% CI 0.78–0.97]), and by conventional 2‐sample MR for OA diagnosis (OR 0.86 [95% CI 0.75–0.98]). MR‐Egger indicated no pleiotropic bias. Genetically predicted elevation in BMI was associated with an increased risk of OA diagnosis (OR 1.65 [95% CI 1.14–2.41]), while MR‐Egger indicated pleiotropic bias and a larger association with OA diagnosis (OR 3.25 [1.26–8.39]), OA joint replacement (OR 3.81 [95% CI 1.39–10.4]), and total OA (OR 3.41 [95% CI 1.43–8.15]). No associations were observed between genetically predicted HDL cholesterol level, triglyceride level, FPG level, or systolic BP and OA outcomes. The associations with LDL cholesterol levels were replicated in the UK Biobank (OR 0.95 [95% CI 0.93–0.98]).

Conclusion

Our MR study provides evidence of a causal role of lower LDL cholesterol level and higher BMI in OA.

Osteoarthritis year in review 2018: imaging

PURPOSE

To provide a narrative review of the most relevant original research published in 2017/2018 on osteoarthritis imaging.

METHODS

The PubMed database was used to recover all relevant articles pertaining to osteoarthritis and medical imaging published between 1 April 2017 and 31 March 2018. Review articles, case studies and in vitro or animal studies were excluded. The original publications were subjectively sorted based on relevance, novelty and impact.

RESULTS AND CONCLUSIONS

The publication search yielded 1,155 references. In the assessed publications, the most common imaging modalities were radiography (N = 708) and magnetic resonance imaging (MRI) (355), followed by computed tomography (CT) (220), ultrasound (85) and nuclear medicine (17). An overview of the most important publications to the osteoarthritis (OA) research community is presented in this narrative review. Imaging studies play an increasingly important role in OA research, and have helped us to understand better the pathophysiology of OA. Radiography and MRI continue to be the most applied imaging modalities, while quantitative MRI methods and texture analysis are becoming more popular. The value of ultrasound in OA research has been demonstrated. Several multi-modality predictive models have been developed. Deep learning has potential for more automatic and standardized analyses in future OA imaging research.

Human C-reactive protein aggravates osteoarthritis development in mice on a high-fat diet

OBJECTIVE

C-reactive protein (CRP) levels can be elevated in osteoarthritis (OA) patients. In addition to indicating systemic inflammation, it is suggested that CRP itself can play a role in OA development. Obesity and metabolic syndrome are important risk factors for OA and also induce elevated CRP levels. Here we evaluated in a human CRP (hCRP)-transgenic mouse model whether CRP itself contributes to the development of 'metabolic' OA.

DESIGN

Metabolic OA was induced by feeding 12-week-old hCRP-transgenic males (hCRP-tg, n = 30) and wild-type littermates (n = 15) a 45 kcal% high-fat diet (HFD) for 38 weeks. Cartilage degradation, osteophytes and synovitis were graded on Safranin O-stained histological knee joint sections. Inflammatory status was assessed by plasma lipid profiling, flow cytometric analyses of blood immune cell populations and immunohistochemical staining of synovial macrophage subsets.

RESULTS

Male hCRP-tg mice showed aggravated OA severity and increased osteophytosis compared with their wild-type littermates. Both classical and non-classical monocytes showed increased expression of CCR2 and CD86 in hCRP-tg males. HFD-induced effects were evident for nearly all lipids measured and indicated a similar low-grade systemic inflammation for both genotypes. Synovitis scores and synovial macrophage subsets were similar in the two groups.

CONCLUSIONS

Human CRP expression in a background of HFD-induced metabolic dysfunction resulted in the aggravation of OA through increased cartilage degeneration and osteophytosis. Increased recruitment of classical and non-classical monocytes might be a mechanism of action through which CRP is involved in aggravating this process. These findings suggest interventions selectively directed against CRP activity could ameliorate metabolic OA development.