Higher Serum Levels of Resistin Are Associated With Knee Synovitis and Structural Abnormalities in Patients With Symptomatic Knee Osteoarthritis

The design of a sample rapid magnetic resonance imaging (MRI) acquisition protocol supporting assessment of multiple articular tissues and pathologies in knee osteoarthritis

Objective

This expert opinion paper proposes a design for a state-of-the-art magnetic resonance image (MRI) acquisition protocol for knee osteoarthritis clinical trials in early and advanced disease. Semi-quantitative and quantitative imaging endpoints are supported, partly amendable to automated analysis. Several (peri-) articular tissues and pathologies are covered, including synovitis.

Method

A PubMed literature search was conducted, with focus on the past 5 years. Further, osteoarthritis imaging experts provided input. Specific MRI sequences, orientations, spatial resolutions and parameter settings were identified to align with study goals. We strived for implementation on standard clinical scanner hardware, with a net acquisition time ≤30 ​min.

Results

Short- and long-term longitudinal MRIs should be obtained at ≥1.5T, if possible without hardware changes during the study. We suggest a series of gradient- and spin-echo-sequences, supporting MOAKS, quantitative analysis of cartilage morphology and T2, and non-contrast-enhanced depiction of synovitis. These sequences should be properly aligned and positioned using localizer images. One of the sequences may be repeated in each participant (re-test), optimally at baseline and follow-up, to estimate within-study precision. All images should be checked for quality and protocol-adherence as soon as possible after acquisition. Alternative approaches are suggested that expand on the structural endpoints presented.

Conclusions

We aim to bridge the gap between technical MRI acquisition guides and the wealth of imaging literature, proposing a balance between image acquisition efficiency (time), safety, and technical/methodological diversity. This approach may entertain scientific innovation on tissue structure and composition assessment in clinical trials on disease modification of knee osteoarthritis.

Thigh muscle and fat volumes are associated with knee cartilage abnormalities and bone marrow edema-like lesions: data from the osteoarthritis initiative

OBJECTIVE

To investigate the associations of thigh muscle and fat volumes with structural abnormalities on MRI related to knee osteoarthritis.

MATERIALS AND METHODS

MRI studies of the thighs and knees from 100 individuals were randomly selected from the Osteoarthritis Initiative Cohort. Whole Organ MR Scoring (WORMS) and effusion-synovitis scoring were performed in all knee MRI. Thigh muscles, intermuscular fat, and subcutaneous fat were manually segmented in 15 consecutive MR thigh images. Radiographic Kellgren-Lawrence grades (KLG) were also obtained in all knee radiographs. Independent t-tests were used to investigate the associations between thigh muscle and fat volumes, and sex. Mixed-effects analyses were obtained to investigate the associations between thigh muscle and fat volumes, KLG, WOMAC pain score, cartilage and bone marrow WORMS, as well as effusion-synovitis scores.

RESULTS

Women had higher subcutaneous fat volume than men (616.82 vs. 229.13 cm3, p < 0.01) and men had higher muscle volumes than women (p < 0.01). Quadriceps (coef = -2.15, p = 0.01) and vastus medialis (coef = -1.84, p = 0.03) volumes were negatively associated with the WORMS cartilage scores. Intermuscular fat volume (coef = 0.48, p = 0.01) was positively associated with WORMS bone marrow edema-like lesion (BMEL) scores. The quadriceps (coef = -0.99, p < 0.01) and hamstring (coef = -0.59, p = 0.01) volumes were negatively associated with WORMS BMEL scores. No evidence of an association was found between thigh muscle and fat volumes with KLG and effusion-synovitis grading (p > 0.05).

CONCLUSION

Increased quadriceps and hamstring volumes were negatively associated with cartilage lesion and BMEL scores while no evidence of an association was found between thigh muscle and fat volumes, and radiographic knee osteoarthritis or effusion-synovitis grading.

Global burden of osteoarthritis in adults aged 30 to 44 years, 1990 to 2019: results from the Global Burden of Disease Study 2019

BACKGROUND

Osteoarthritis (OA) is a common orthopedic disorder, and its incidence has been increasing among young adults in recent years. The purpose of this study is to investigate the global, regional, and national trends in OA burden and variation among individuals aged 30 to 44 from 1990 to 2019.

METHODS

Data on the incidence, prevalence, and years lived with disability (YLDs) related to OA were sourced from the Global Burden of Disease Study 2019 among individuals aged 30 to 44. These measures were stratified by gender, region, country, and socio-demographic index (SDI). Additionally, we analyzed YLDs attributable to risk factors.

RESULTS

In 2019, there were a total of 32,971,701 cases of OA among individuals aged 30 to 44 years worldwide, with an additional 7,794,008 new incident cases reported. OA of the knee was the primary contributor to both incidence and prevalence rates over the past three decades. From 1990 to 2019, both males and females in countries with high SDI and high-middle SDI showed upward trends in age-standardized incidence, prevalence, and YLDs rates. In 2019, the United States of America had the highest age-standardized incidence, prevalence, and YLDs rates. Elevated body-mass index (BMI) was found to be the most prevalent risk factor for osteoarthritis-related YLDs. Age-standardized YLDs rates were positively associated with SDI.

CONCLUSIONS

OA remains a significant disease burden on individuals aged 30 to 44, with modifiable risk factors such as unhealthy lifestyle and obesity representing key targets for future interventions aimed at reducing the impact of this condition on younger generations.

Obesity, Metabolic Syndrome, and Osteoarthritis-An Updated Review

PURPOSE OF REVIEW

Metabolic syndrome (MetS), also called the 'deadly quartet' comprising obesity, diabetes, dyslipidemia, and hypertension, has been ascertained to have a causal role in the pathogenesis of osteoarthritis (OA). This review is aimed at discussing the current knowledge on the contribution of metabolic syndrome and its various components to OA pathogenesis and progression.

RECENT FINDINGS

Lately, an increased association identified between the various components of metabolic syndrome (obesity, diabetes, dyslipidemia, and hypertension) with OA has led to the identification of the 'metabolic phenotype' of OA. These metabolic perturbations alongside low-grade systemic inflammation have been identified to inflict detrimental effects upon multiple tissues of the joint including cartilage, bone, and synovium leading to complete joint failure in OA. Recent epidemiological and clinical findings affirm that adipokines significantly contribute to inflammation, tissue degradation, and OA pathogenesis mediated through multiple signaling pathways. OA is no longer perceived as just a 'wear and tear' disease and the involvement of the metabolic components in OA pathogenesis adds up to the complexity of the disease. Given the global surge in obesity and its allied metabolic perturbations, this review aims to throw light on the current knowledge on the pathophysiology of MetS-associated OA and the need to address MetS in the context of metabolic OA management. Better regulation of the constituent factors of MetS could be profitable in preventing MetS-associated OA. The identification of key roles for several metabolic regulators in OA pathogenesis has also opened up newer avenues in the recognition and development of novel therapeutic agents.

Effect of cell receptors in the pathogenesis of osteoarthritis: Current insights

Osteoarthritis (OA) is a chronic arthritic disease characterized by cartilage degradation, synovial inflammation, and subchondral bone lesions. The studies on the pathogenesis of OA are complex and diverse. The roles of receptors signaling in chondrocyte anabolism, inflammatory factors expression of synovial fibroblast, and angiogenesis in subchondral bone are particularly important for exploring the pathological mechanism of OA and clinical diagnosis and treatment. By reviewing the relevant literature, this article elaborates on the abnormal expression of receptors and the signaling transduction pathways from different pathological changes of OA anatomical components, aiming to provide new research ideas and clinical therapeutic value for OA pathogenesis.

Longitudinal association of infrapatellar fat pad signal intensity alteration with biochemical biomarkers in knee osteoarthritis

OBJECTIVE

To explore the longitudinal association of quantitative infrapatellar fat pad (IPFP) signal intensity alteration with OA-related biomarkers.

METHODS

Eighteen OA-related biochemical biomarkers of 600 knee OA participants in the Foundation for the National Institutes of Health OA Biomarkers Consortium (FNIH) study were extracted. The quantitative IPFP signal intensity measures were acquired based on magnetic resonance imaging, including mean value [Mean (IPFP)] and standard deviation [sDev (IPFP)] of the whole IPFP signal intensity, median value [Median (H)] and upper quartile value [UQ (H)] of high signal intensity, the ratio of volume of high signal intensity to volume of whole IPFP signal intensity [Percentage (H)] and Clustering factor (H). The linear mixed-effect model was applied to determine the longitudinal associations between IPFP signal intensity alteration and biochemical biomarkers over 2 years.

RESULTS

All IPFP measures except for Clustering factor (H) were positively associated with urine collagenase-cleaved type II collagen neoepitope (uC2C), urine C-terminal cross-linked telopeptide of type II collagen (uCTX-II), urine C-terminal cross-linked telopeptide of type I collagen-α (uCTX-Iα) and urine N-terminal cross-linked telopeptide of type I collagen (uNTX-I). Mean (IPFP), Median (H) and Percentage (H) were positively associated with the nitrated form of an epitope located in the triple helix of type II collagen (Coll2-1 NO2). Mean (IPFP), Median (H) and UQ (H) were positively associated with sCTX-I and uCTX-Iβ. Positive associations between sDev (IPFP), Percentage (H) and serum hyaluronic acid (sHA) were found.

CONCLUSION

Our results suggest a role of IPFP signal intensity alteration in joint tissue remodelling on a molecular level.

Association of serum levels of inflammatory markers and adipokines with joint symptoms and structures in participants with knee osteoarthritis

OBJECTIVE

To investigate the longitudinal associations of serum inflammatory markers and adipokines with joint symptoms and structures in participants with knee osteoarthritis (OA).

METHODS

Two hundred participants (46.5% female, mean age 63.1 years, mean BMI 29.5 kg/m2) from Tasmania part of the VIDEO (Vitamin D Effect on OA) study were randomly selected in the current study. Serum levels of 19 biomarkers, scores of Western Ontario and McMaster Universities Index (WOMAC), and magnetic resonance imaging-assessed knee structures were evaluated at baseline and month 24. The patterns of biomarkers were derived from principal component analysis and their association with knee symptoms and structures were examined using adjusted generalized estimating equations.

RESULTS

Five components explained 78% of the total variance. Interleukin (IL)-1β, -2, -4, -6, -8, -17A, -17F, -21, -22 and -23 loaded the highest on the first component, which was associated with increased bone marrow lesions (BMLs) and WOMAC dysfunction score. IL-10, -12 and granulocyte-macrophage colony-stimulating factor loaded on the second component, which was associated with increased cartilage volume, and decreased effusion-synovitis and WOMAC scores. Leptin, adipsin and C-reactive protein loaded on the third component, which was positively associated with WOMAC scores. Resistin loaded on the fourth component, which was associated with increased BMLs and cartilage defects. Apelin-36 and adiponectin loaded on the fifth component, which was associated with increased BMLs.

CONCLUSION

Various inflammatory and metabolic components were associated differently with joint symptoms and structural changes in knee OA, suggesting a complex inflammatory and metabolic inter-relationship in the pathogenesis of knee OA.