Risk of Knee Osteoarthritis With Obesity, Sarcopenic Obesity, and Sarcopenia

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.

Pro-Inflammatory Biomarkers Combined with Body Composition Display a Strong Association with Knee Osteoarthritis in a Community-Based Study

Knee osteoarthritis (KOA) is one of the most common progressive, age-dependent chronic degenerative joint diseases. KOA often develops as a result of a gradual articular cartilage loss caused by its wear and tear. Numerous studies suggest that the degradation of the knee joint involves inflammatory components. This process is also associated with body composition, particularly being overweight and muscle mass loss. The present study aimed to search for novel circulating KOA inflammatory biomarkers, taking into account body composition characteristics. To this aim, we recruited 98 patients diagnosed and radiologically confirmed with KOA and 519 healthy controls from the Arab community in Israel. A panel of soluble molecules, related to inflammatory, metabolic, and musculoskeletal disorders, was measured by ELISA in plasma samples, while several body composition parameters were assessed with bioimpedance analysis. Statistical analysis, including multivariable logistic regression, revealed a number of the factors significantly associated with KOA, independently of age and sex. The most significant independent associations [OR (95% CI)] were fat body mass/body weight index-1.56 (1.20-2.02), systemic immune-inflammation index-4.03 (2.23-7.27), circulating vaspin levels-1.39 (1.15-1.68), follistatin/FSTL1 ratio-1.32 (1.02-1.70), and activin A/FSTL1 ratio-1.33 (1.01-1.75). Further clinical studies are warranted to confirm the relevance of these KOA-associated biological factors. Hereafter, they could serve as reliable biomarkers for KOA in the general human population.

Obesity-Related Knee Osteoarthritis-Current Concepts

The knee is the joint most frequently involved in osteoarthritis and represents a significant contributor to patient morbidity and impaired functional status. Major risk factors include genetics, age, sex, mechanical load and obesity/metabolic syndrome. Recent studies highlighted the role of obesity and metabolic syndrome in the pathogenesis of knee osteoarthritis not simply through increased mechanical loading but the systemic effects of obesity-induced inflammation. The current concept of knee osteoarthritis is that of a 'whole joint disease', which highlights the involvement not only of articular cartilage but also the synovium, subchondral bone, ligaments and muscles. Obesity and metabolic syndrome are associated with higher levels of pro-inflammatory cytokines, increased production of adipokines with both protective and destructive effects on articular cartilage, an up-regulation of proteolytic enzymes such as matrix metalloproteinases and aggrecanases and an increase in free fatty acids and reactive oxygen species induced by dyslipidemia. These findings underscore that the adequate management of knee osteoarthritis needs to include an optimization of body weight and a beneficial mobility regimen. The possible introduction of pharmacological therapy targeting specific molecules involved in the pathogenesis of obesity-related osteoarthritis will likely also be considered in future therapeutic strategies, including personalized treatment approaches.

Factors Mediating or Moderating the Effects of Obesity on Walking: Targeting Areas for Rehabilitation

Increased physical activity, such as walking, is often prescribed to address obesity. Several factors that may influence the connection between obesity and walking include the biomechanics of gait, pain, depressive symptoms, physical health, and activity. The objective of this study was to assess the moderation and mediation effects of knee pain and buckling, depressive symptoms, physical activity, and physical health on spatiotemporal gait parameters in individuals with obesity. Forty participants with obesity performed a task in which they walked on flat ground and crossed an obstacle. Measures of knee pain and buckling, depressive symptoms, physical activity, and physical health were collected. We conducted mediation analyses with knee buckling and pain as mediators of the effect of the BMI on spatiotemporal gait parameters. Moderation analyses were performed with depressive symptoms, physical activity, and physical health as moderators of the effect of BMI on spatiotemporal gait parameters. We found that depressive symptoms and physical health moderated the relationship between BMI and Step Width in people with obesity. These effects were pronounced when participants crossed an obstacle. In conclusion, depressed mood and physical health influence the relationship between obesity and walking. These factors present potential avenues for rehabilitation interventions to aid individuals with obesity.

The burden of osteoarthritis due to high Body Mass Index in Iran from 1990 to 2019

High BMI related burden of knee and hip osteoarthritis (OA) is on a significant rise worldwide. OA not only causes joint pain and stiffness, but it also leads to disability. This study investigated the trend and burden of OA attributable to high body mass index (BMI) in Iran. The age-standardized disability-adjusted life years (DALYs) rates of knee and hip OA due to high BMI, were estimated using data from the Global Burden of Disease 2019. We evaluated DALYs rate trend of high BMI related OA by sex and age in span of 30 years from 1990-2019 across the 31 provinces of Iran. The age-standardized prevalence trend of OA in the knee and hip showed an increase from 1990 to 2019. In 2019 there were 29.92 (95% CI: 10.98-64.92) and 42.50 (95% CI: 16.32-97.37) DALYs/100,000 related to OA from high BMI in men and women, respectively. 2019 saw the greatest DALYs/100,000 rate in the 65-79 age group. From 2005 to 2019, men and women saw DALYs/100,000 rate changes of 24.87 and 17.43 percent, respectively. The burden of knee OA was significantly higher than that of hip OA. DALYs rate of OA due to high BMI was found to be positively associated with the Socio-demographic Index (SDI). The burden of knee and hip OA due to high BMI has increased significantly in recent years in Iran among all age groups of both men and women. It is recommended that health policymakers develop weight control strategies to reduce the burden of OA and implement them at the national level.

Osteoarthritis and sarcopenia-related traits: the cross-sectional study from NHANES 2011-2014 and Mendelian randomization study

BACKGROUND

Osteoarthritis (OA) and sarcopenia are common musculoskeletal disorders in the aged population, and a growing body of evidence indicated that they mutually influence one another. Nevertheless, there was still substantial controversy and uncertainty about the causal relationship between sarcopenia and OA. We explored the complex association between sarcopenia-related traits and OA using cross-sectional analysis and Mendelian randomization (MR).

METHODS

The cross-sectional study used the data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014. Weighted multivariable-adjusted logistic regression and subgroup analyses were used to evaluate the correlation between sarcopenia, grip, appendicular lean mass (ALM) and the risk of OA. Then, we further performed MR analysis to examine the causal effect of sarcopenia-related traits (grip strength, ALM) on OA. Instrumental variables for grip strength and ALM were from the UK Biobank, and the summary-level data for OA was derived from the Genetics of Osteoarthritis (GO) Consortium GWAS (n = 826,690).

RESULTS

In this cross-sectional analysis, we observed that sarcopenia, grip were significantly linked with the risk of OA (OR 1.607, 95% CI 1.233-2.094, P < 0.001), (OR 0.972, 95% CI 0.964-0.979, P < 0.001). According to subgroup analyses stratified by gender, body mass index (BMI), and age, the significant positive relationship between sarcopenia and OA remained in males, females, the age (46-59 years) group, and the BMI (18.5-24.9 kg/m²) group (P < 0.05). Furthermore, MR analysis and sensitivity analyses showed causal associations between right grip, left grip and KOA (OR 0.668; 95% CI 0.509 to 0.877; P = 0.004), (OR 0.786; 95% CI 0.608 to 0.915; P = 0.042). Consistent directional effects for all analyses were observed in both the MR-Egger and weighted median methods. Subsequently, sensitivity analyses revealed no heterogeneity, directional pleiotropy or outliers for the causal effect of grip strength on KOA (P > 0.05).

CONCLUSIONS

Our research provided evidence that sarcopenia is correlated with an increased risk of OA, and there was a protective impact of genetically predicted grip strength on OA. These findings needed to be verified in further prospective cohort studies with a large sample size.

Personalized Nutritional Strategies to Reduce Knee Osteoarthritis Severity and Ameliorate Sarcopenic Obesity Indices: A Practical Guide in an Orthopedic Setting

Knee osteoarthritis (KOA) is one of the most common joint diseases, especially in individuals with obesity. Another condition within this population, and which presents frequently, is sarcopenic obesity (SO), defined as an increase in body fat and a decrease in muscle mass and strength. The current paper aims to describe recent nutritional strategies which can generally improve KOA clinical severity and, at the same time, ameliorate SO indices. Searches were carried out in the PubMed and Science Direct databases and data were summarized using a narrative approach. Certain key findings have been revealed. Firstly, the screening and identification of SO in patients with KOA is important, and to this end, simple physical performance tests and anthropometric measures are available in the literature. Secondly, adherence to a Mediterranean diet and the achievement of significant body weight loss by means of low-calorie diets (LCDs) remain the cornerstone nutritional treatment in this population. Thirdly, supplementation with certain micronutrients such as vitamin D, essential and non-essential amino acids, as well as whey protein, also appear to be beneficial. In conclusion, in the current review, we presented a detailed flowchart of three different nutritional tracks that can be adopted to improve both KOA and SO based on joint disease clinical severity.

The Relationship Between Sarcopenic Obesity and Knee Osteoarthritis: The SARCOB Study

BACKGROUND

To investigate whether sarcopenic obesity may contribute to knee osteoarthritis or not.

METHODS

In this study, we assessed 140 community-dwelling adult patients. Their demographic data were recorded along with comorbidities. Anterior mid-thigh muscle thickness in the axial plane was measured on the dominant leg using ultrasound midway between the anterior superior iliac spine and the upper end of patella in millimeter. Then, the sonographic thigh adjustment ratio was calcu- lated by dividing this thickness by body mass index. ISarcoPRM algorithm was used for the diagnosis of sarcopenia. Kellgren-Lawrence grading was used for knee osteoarthritis . Functional evaluation was performed using chair stand test, gait speed, and grip strength.

RESULTS

There were 50 patients with knee osteoarthritis and 90 age- and gender-similar control sub- jects. When compared with controls, anterior thigh muscle thickness, gait speed, and grip strength were found to be similar between the groups, whereas body mass index and chair stand test val- ues were higher in the knee osteoarthritis group (both P < .05). In addition, sarcopenic obesity was observed in 12 (13.3%) of control subjects and in 14 (28%) of osteoarthritis patients. When age, gen- der, exercise, smoking, and body composition type (i.e., nonsarcopenic nonobese, sarcopenic only, obese only, and sarcopenic obesity) were taken into binary logistic regression analyses, only sarcope- nic obesity [relative risk ratio = 2.705 (95% CI: 1.079-6.779)] was independently related with the knee osteoarthritis (P < .05).

CONCLUSION

Our preliminary study has shown that neither sarcopenia nor obesity but sarcopenic obe- sity seems to be independently related to the knee osteoarthritis. Further longitudinal studies with larger samples are required for investigating the effects of obesity and sarcopenia on the develop- ment of knee osteoarthritis.

Does Sarcopenia Accompanying End-Stage Knee Osteoarthritis Affect the Outcomes following Total Knee Arthroplasty?

Background and Objectives: This study aimed to investigate the prevalence of sarcopenia in patients undergoing total knee arthroplasty (TKA) for advanced knee osteoarthritis (OA), and to assess whether sarcopenia accompanying OA affects patient-reported outcome measures (PROMs) after TKA. We evaluated which predisposing factors could influence the development of sarcopenia in patients with advanced knee OA. Material and Methods: A total of 445 patients whose body composition, muscle strength, and physical performance could be measured before primary TKA were enrolled. Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019 criteria. Patients were categorized into sarcopenia (S, n = 42) and non-sarcopenia groups (NS, n = 403). PROMs were investigated using the Knee Injury and Osteoarthritis Outcome Score and Western Ontario and McMaster Universities Osteoarthritis Index. Additionally, postoperative complications and predisposing factors for sarcopenia were evaluated. Results: The incidence of sarcopenia in the entire sample was 9.4%; the prevalence was higher in men (15.4%) than in women (8.7%), and significantly increased with advancing age (p < 0.001). At the six-month follow-up, PROMs in group S were significantly inferior to those in group NS, except for the pain score; however, at the 12-month follow-up, no significant difference was observed between the groups. Multivariate logistic regression indicated that age, body mass index (BMI), and a higher modified Charlson Comorbidity Index (mCCI) were predisposing factors for sarcopenia. Conclusions: A higher prevalence of sarcopenia was observed in men with progressive knee OA. Up to six months after primary TKA, PROMs in group S were inferior to those in group NS, except for the pain score; however, no significant difference was observed between the groups at 12 months. Age, BMI, and higher mCCI were predisposing factors for sarcopenia in patients with OA.

A systematic review of the sex differences in risk factors for knee osteoarthritis

OBJECTIVES

Previous systematic reviews focused on the evidence of common risk factors for knee OA (KOA); however, the effect and strength of association between risk factors and KOA might be different between the two sexes. The aim of the present systematic review was to determine the current evidence on sex differences in the association between risk factors and KOA and their prevalence.

METHODS

We searched the following electronic bibliographic databases: MEDLINE (PubMed), EMBASE and Web of Science. A methodological quality assessment was conducted independently by two researchers according to an adapted version of the standardized set of criteria known as the Newcastle-Ottawa Quality Assessment Scale (NOS). The NOS, a star system, was converted to three categories of quality.

RESULTS

In total, 27 studies reported sex-specific risk estimates on several risk factors for KOA. Out of the 22 longitudinal cohort studies (except one nested case-control), 12 were of good quality and 10 were of fair quality. The five cross-sectional studies consisted of one of good, three of fair and one of poor quality. There was an indication of sex differences in risk factors leading to higher risk of KOA: high BMI, alcohol consumption, atherosclerosis and high vitamin E levels in women, and high physical activity, soft drink consumption and abdominal obesity in men. Knee injury, high blood pressure and low step rate seem to affect both women and men.

CONCLUSION

More good quality studies are needed to assess sex differences in risk factors for KOA, especially for symptomatic/clinical OA.

Sarcopenia and Sarcopenic Obesity and Osteoarthritis: A Discussion among Muscles, Fat, Bones, and Aging

Aging is a physical procedure for people and nature. Our aging world is expanding because of the life span extension. Aging has a crucial relationship with our body composition (muscles, bones, and adipose tissue), which is characterized by an increase in fat mass and a gradual decrease in muscle mass and strength and bone density. These alterations affect physical performance and impact quality of life enhancing the risk for non-communicable diseases, immobilization, and disability. As far we know, osteoarthritis of lower limbs, sarcopenic obesity, and muscle mass and/or strength loss are treated separately. However, bones, muscles, adipose tissue, and aging appear to have an interconnection through a dialogue as they talk to each other. Health disorders are coming into the surface when this relationship is disrupted. The aim of our study is to search deeper into this interconnection, so that when adipose tissue increases, we have to take a look into the condition of muscle mass, bone, and connective tissue and vice versa, through the assessment of physical performance. Consequently, the triad muscle-bone-adipose tissue disorders by aging should be treated as a single entity.

Effect of green-lipped mussel (Perna canaliculus) supplementation on faecal microbiota, body composition and iron status markers in overweight and obese postmenopausal women: a randomised, double-blind, placebo-controlled trial

The present study aimed to determine the effect of whole meat GSM powder on gut microbiota abundance, body composition and iron status markers in healthy overweight or obese postmenopausal women. This was a 3-months trial involving forty-nine healthy postmenopausal women with body mass index (BMI) between 25 and 35 kg/m2 who were randomly assigned to receive 3 g/d of either GSM powder (n 25) or placebo (n 24). The gut microbe abundance, serum iron status markers and body composition were measured at the baseline and the end of the study. The between-group comparison at the baseline showed a lower abundance of Bacteroides and Clostridium XIVa in the GSM group compared with the placebo (P = 0⋅04). At the baseline, the body fat (BF)% and gynoid fat% were higher in the GSM group compared with the placebo (P < 0⋅05). No significant changes were found in any of the outcome measures, except for ferritin levels that showed a significant reduction over time (time effect P = 0⋅01). Some trend was observed in bacteria including Bacteroides and Bifidobacterium which tended to increase in the GSM group while their abundance decreased or remained at their baseline level in the control group. Supplementation with GSM powder did not result in any significant changes in gut microbe abundance, body composition and iron markers compared with placebo. However, some commensal bacteria such as Bacteroides and Bifidobacteria tended to increase following supplementation with GSM powder. Overall, these findings can expand the knowledge surrounding the effects of whole GSM powder on these outcome measures in healthy postmenopausal women.

Demographic and radiographic factors for knee symptoms and range of motion in patients with knee osteoarthritis: a cross-sectional study in Beijing, China

BACKGROUND

Knee osteoarthritis (KOA) causes not only pain, stiffness, and dysfunction of the knee, but also the reduction of the joint range of motion (ROM). This study explored the demographic and radiographic factors for knee symptoms and ROM in patients with symptomatic KOA.

METHODS

The demographic variables, Kellgren-Lawrence (KL) grade, and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) of patients with symptomatic KOA recruited in Beijing were collected. The knee ROM of all patients were also measured. We analyzed the influencing factors for WOMAC and ROM using a generalize linear model, respectively.

RESULTS

This study included a total of 2034 patients with symptomatic KOA, including 530 males (26.1%) and 1504 females (73.0%), with a mean age of 59.17 (± 10.22) years. Patients with advanced age, overweight or obesity, a family history of KOA, a moderate-to-heavy manual labor job and use of nonsteroidal anti-inflammatory drugs (NSAIDs) had significantly higher WOMAC and lower ROM (all P < 0.05). The more the comorbidities, the higher the WOMAC (all P < 0.05). Patients with higher education had better ROM than those with only an elementary education(β = 4.905, P < 0.05). Compared with those KL = 0/1, the WOMAC of patients whose KL = 4 were higher (β = 0.069, P < 0.05), but the WOMAC of those KL = 2 were lower (β = -0.068, P < 0.05). ROM decreased with the increase of KL grade (all P < 0.05).

CONCLUSIONS

KOA patients with advanced age, overweight or obesity, a family history of KOA in first-degree relatives, a moderate-to-heavy manual labor job tended to have more severe clinical symptoms and worse ROM. Patients with more severe imaging lesions tend to have poorer ROM. Symptom management measures and regular ROM screening should be taken early to these people.

Effects of Protein Supplementation Combined with Resistance Exercise Training on Walking Speed Recovery in Older Adults with Knee Osteoarthritis and Sarcopenia

Knee osteoarthritis (KOA) is closely associated with sarcopenia, sharing the common characteristics of muscle weakness and low physical performance. Resistance exercise training (RET), protein supplementation (PS), and PS+RET have promise as treatments for both sarcopenia and KOA. However, whether PS+RET exerts any effect on time to recovery to normal walking speed (WS) in older adults with sarcopenia and KOA remains unclear. This study investigated the treatment efficiency of PS+RET on WS recovery among individuals with KOA and sarcopenia. A total of 108 older adults aged ≥ 60 years who had a diagnosis of radiographic KOA and sarcopenia were enrolled in this prospective cohort study. Sarcopenia was defined on the basis of the cutoff values of the appendicular skeletal muscle mass index for Asian people and a slow WS less than 1.0 m/s. The patients were equally distributed to three groups: PS+RET, RET alone, and usual care. The weekly assessment was performed during a 12-week intervention and a subsequent 36-week follow-up period. A cutoff of 1.0 m/s was used to identify successful recovery to normal WS. Kaplan-Meier analysis was performed to measure the survival time to normal WS among the study groups. Multivariate Cox proportional-hazards regression (CPHR) models were established to calculate the hazard ratios (HRs) of successful WS recovery and determine its potential moderators. After the 3-month intervention, PS+RET as well as RET obtained greater changes in WS by an adjusted mean difference of 0.18 m/s (p < 0.0001) and 0.08 (p < 0.05) m/s, respectively, compared to usual care. Kaplan-Meier analysis results showed both RET and PS+RET interventions yielded high probabilities of achieving normal WS over the 12-month follow-up period. Multivariate CPHR results revealed that PS+RET (adjusted HR = 5.48; p < 0.001), as well as RET (adjusted HR = 2.21; p < 0.05), independently exerted significant effects on WS recovery. PS+RET may accelerate normal WS recovery by approximately 3 months compared with RET. Sex and initial WS may influence the treatment efficiency. For patients with KOA who suffer sarcopenia, 12-week RET alone exerts significant effects on WS recovery, whereas additional PS further augments the treatment effects of RET by speeding up the recovery time of WS toward a level ≥ 1.0 m/s, which facilitates the patients to diminish the disease severity or even free from sarcopenia.

Factores de riesgo asociados a la artrosis de rodilla: Revisión sistemática de la literatura

Introducción: la osteoartritis de rodilla (OR) se define como una enfermedad crónica, inflamatoria, degenerativa y progresiva, caracterizada por el deterioro del cartílago articular. Tiene manifestaciones clínicas y etiológicas diferentes según el grupo etario y se encuentra asociada con múltiples factores que intervienen en la fisiopatología, entre los que están: edad, raza, sexo, sobrepeso, obesidad y síndrome metabólico. Objetivo: determinar los factores de riesgo que influyen en el proceso degenerativo de la OR en la adultez temprana y tardía. Materiales y métodos: revisión sistemática de la literatura científica en diferentes bases de datos que incluyeron estudios de cohorte, transversales, casos y controles, evaluando los factores de riesgo predisponentes. Resultados: se seleccionaron 50 artículos que cumplieron con los criterios, identificando diferentes factores que afectan el desarrollo o progresión de la OR como las alteraciones metabólicas, sistémicas y estilo de vida que influyen en esta patología, además de factores modificables y no modificables. Conclusión: la OR es una afección de carácter multifactorial, donde la obesidad, la hipertensión arterial (HTA), el índice de masa corporal (IMC) elevado, los niveles altos de LDL, la debilidad muscular e incluso la profesión del paciente, son los principales factores predisponentes para desarrollar o aumentar su progresión.

Prevalence of Sarcopenia in Knee Osteoarthritis: A Systematic Review and Meta-Analysis

An association between knee osteoarthritis (OA) and sarcopenia has been proposed, but the evidence is controversial, with the recent literature showing disparate results. Therefore, we aimed to perform a systematic review and meta-analysis to evaluate the prevalence of sarcopenia in knee OA patients compared to people not affected by this condition. We searched several databases until 22 February 2022. The data regarding prevalence were summarized using odds ratios (ORs) with their 95% confidence intervals (CIs). Among the 504 papers initially screened, 4 were included for a total of 7495 participants with a mean age of 68.4 years, who were mainly females (72.4%). The prevalence of sarcopenia in people with knee OA was 45.2%, whilst, in the controls, it was 31.2%. Pooling the data of the studies included that the prevalence of sarcopenia in knee OA was more than two times higher than in the control group (OR = 2.07; 95%CI: 1.43-3.00; I2 = 85%). This outcome did not suffer any publication bias. However, after removing an outlier study, the recalculated OR was 1.88. In conclusion, the presence of sarcopenia in knee OA patients was high, affecting one person in every two persons and was higher than in the control groups included.

Metformin attenuates high-fat diet induced metabolic syndrome related osteoarthritis through inhibition of prostaglandins

High-fat diet induces bone marrow inflammation and osteoarthritis phenotype in knee joint, but the underlying mechanisms is unknown. Here, we report that high-fat diet induces aberrant bone formation and cartilage degeneration in knee joint. Mechanistically, a high-fat diet increases the number of macrophages and the secretion of prostaglandins in subchondral bone, promoting bone formation. Metformin treatment is able to decrease the number of macrophages and also the level of prostaglandins induced by high-fat diet in subchondral bone. Importantly, metformin rescues aberrant bone formation and cartilage lesions by decreasing the number of osteoprogenitors and type-H vessels, which also results in relief of osteoarthritis pain response. Thus, we demonstrate prostaglandins secreted by macrophages may be a key reason for high-fat diet induced aberrant bone formation and metformin is a promising therapy for high-fat diet induced osteoarthritis.

Causal Relationships of General and Abdominal Adiposity on Osteoarthritis: A Two-Sample Mendelian Randomization Study

Background: Adiposity is closely related to osteoarthritis, but the causal effects of different types of adiposity on osteoarthritis are indistinct. This study conducted a Mendelian Randomization (MR) analysis for the causal effects of general adiposity and abdominal adiposity on knee osteoarthritis (KOA) and hip osteoarthritis (HOA). Methods: The general adiposity was assessed by body mass index (BMI), while the abdominal adiposity was evaluated with waist circumference (WC), hip circumference (HC), and waist-to-hip ratio (WHR). The data used in this two-sample MR analysis originated from genome-wide association studies (GWAS). Significant (p < 5 × 10−8) and independent (r2 < 0.01) single-nucleotide polymorphisms were selected as instrumental variables for the MR analysis. Subsequently, this study used the inverse variance weighted, weighted median, and other methods for the causal inference, and the results were presented as odds ratios (OR). Moreover, sensitivity analyses were conducted to assess the stability and reliability of the results. Results: The MR results revealed positive causal effects of BMI on KOA (OR: 1.694; 95% CI: from 1.492 to 1.923; p = 3.96 × 10−16) and HOA (OR: 1.412; 95% CI: from 1.196 to 1.666; p = 4.58 × 10−5). Additionally, WC and HC both positively and causally related to KOA (WC: OR: 1.827; 95% CI: from 1.564 to 2.134; p = 2.68 × 10−14; HC: OR: 1.610; 95% CI: from 1.357 to 1.912; p = 5.03 × 10−8) and HOA (WC: OR: 1.491; 95% CI: from 1.254 to 1.772; p = 5.85 × 10−6; HC: OR: 1.439; 95% CI: from 1.205 to 1.719; p = 5.82 × 10−5). However, no causal relationship existed between WHR and obesity. These results were robust according to the sensitivity analyses. Conclusions: This study indicated that both general and abdominal obesity had positive causal effects on knee osteoarthritis and hip osteoarthritis.

Lower limb inter-joint coordination in individuals with osteoarthritis before and after a total knee arthroplasty

BACKGROUND

Total knee arthroplasty is the most common treatment for severe knee osteoarthritis. Coordination and variability analyses are effective measures of the injury stage or rehabilitation process. This study compared the inter-joint coordination before and after arthroplasty, compared to controls.

METHODS

Twenty-seven patients were evaluated before and 12 months after surgery, compared to 27 controls. Coordination and variability in the sagittal plane between the hip-knee and knee-ankle were calculated using vector coding and circular statistics. Coordination was categorized as in-phase, anti-phase, or distal or proximal joint-phase. The gait cycle was divided into sub-phases for the coordination, variability, and range of motion results.

FINDINGS

Coordination and range of motion differed significantly between the patient groups and controls, while small differences between pre- and post-operative groups were also detected. The hip-knee showed a reduced in-phase frequency in the patient group compared to control during stance, particularly mid-stance: pre-operative 24.3% ± 33.9, post-operative 29.5 ± 29.7, and controls 70.7 ± 17.0. This difference was compensated for by increasing proximal-phase (hip) frequency in the patient groups. For knee-ankle coordination, the patient groups showed higher distal-phase (ankle) frequency during the early and mid-stance. Coordination variability was higher post-operatively during swing and terminal swing phases, compared to controls.

INTERPRETATION

The results indicated reduced degrees of freedom for the knee during stance phase with a reduced capacity to move the knee and hip in opposing directions before and one year after surgery. The patient group after the surgery increased knee range of motion and coordination compared to pre-operative during swing phase.

Knee osteoarthritis pre-screening questionnaire (KOPS): cross-cultural adaptation and measurement properties of the brazilian version-KOPS Brazilian version

BACKGROUND

Despite the criteria already established for the classification of knee osteoarthritis (OA), a radiographic and/or clinical knee OA diagnosis usually occurs in cases of fully manifest or more advanced disease, which can make health promotion, prevention, and functional rehabilitation in more advanced stages of the disease less effective. In addition, radiographic knee OA can generate more financial costs for health services. Therefore, developing and validating screening instruments to assess the probability of development and progression of knee OA would be of great value for both clinical practice and science.

OBJECTIVE

To cross-culturally adapt and investigate the measurement properties of the Knee OA Pre-screening Questionnaire Brazilian version.

METHODS

A total of 250 individuals of both sexes aged between 35 and 92 years [(mean (standard deviation): 63 (11) years old; 74.1 (15.1) kg; 1.59 (0.09) m; 29.38 (5.44) kg/m²] participated in this study. The cross-cultural adaptation and analyses of the measurement properties of the KOPS Brazilian version included: (1) assessment of conceptual and item equivalence; (2) assessment of semantic equivalence; (3) assessment of operational equivalence; and (4) assessment of measurement equivalence, reliability, and validity.

RESULTS

Cronbach's alpha for the internal consistency among the six components of the KOPS Brazilian version was 0.71. The test-retest 72 h apart for each component resulted in a coefficient correlation intraclass ranging from 0.74 to 1.00. The probability of an individual randomly chosen from the population having KL ≥ 1 and KOPS Brazilian version ≥ 21 points was 0.74 (area under the curve of the Receiver Operating Characteristic - AUC of ROC); furthermore, the AUC for KL ≥ 2 and the KOPS Brazilian version ≥ 23 points was 0.77.

CONCLUSION

The KOPS Brazilian version is a reliable and valid instrument for early screening of knee OA in individuals aged 35 years and over in the Brazilian context.

Prescription of resistance training for sarcopenic older adults: Does it require specific attention?

Sarcopenia is an age-related neuromuscular disease characterized by substantial muscle atrophy, dynapenia and/or loss of physical function. Sarcopenia progression increases the risk for numerous negative events, including falls, disability, hospitalization, nursing home placement, and death. As such, this condition is recognized as an important topic in gerontology and geriatrics. The best approach to counteract the development and progression of sarcopenia is actively debated. Resistance training (RT) has received special attention in this context, owing to the large number of studies showing its ability to produce significant improvements in sarcopenia-related parameters. Recommendations to guide RT prescription for older adults with different conditions, including people who have traits of sarcopenia, have been published. Some authors have argued that RT guidelines for older adults are similar to one another, which may indicate that the presence of sarcopenia does not require specific physical exercise programs. However, older people with sarcopenia might present with peculiar physical, biomechanical, physiological, and psychosocial characteristics that, in our view, are not taken into adequate consideration in existing exercise guidelines. Here, we present evidence to support the view that RT prescription for older adults with sarcopenia is complex, multifactorial, and still needs more evidence.

The Role of AIM2 Inflammasome in Knee Osteoarthritis

Knee osteoarthritis (KOA), whose prevalence keeps rising, is still unsolved pathobiological/therapeutical problem. Historically, knee osteoarthritis was thought to be a "wear and tear" disease, while recent etiology hypotheses stressed it as a chronic, low-grade inflammatory disease. Inflammasomes mediated by the innate immunity systems have an important role in inflammatory diseases including KOA. A deluge of recent studies focused on the NLRP3 inflammasome with suggestions that its pharmacologic block would hinder degeneration. However, known inflammasomes are numerous and can also trigger IL-1β/IL-18 production and cells' pyroptotic death. Among them, AIM2 inflammasome is involved in key aspects of various acute and chronic inflammatory diseases. Therefore, while presently leaving out little-studied inflammasomes in KOA, this review focuses on the AIM2 inflammasomes that participate in KOA's complex mechanisms in conjunction with the activation of AIM2 inflammasomes in other diseases combined with the current studies on KOA mechanisms. Although human-specific data about it are relatively scant, we stress that only a holistic view including several inflammasomes including AIM2 inflammasome and other potential pathogenetic drivers will lead to successful therapy for knee osteoarthritis.

Cross-sectional and longitudinal assessment of subchondral cysts in temporomandibular joints: Clinical and MRI study with a mean follow-up of 66 months

PURPOSE

This observational study aimed to elucidate the pathophysiology of subchondral cysts (SC) in the temporomandibular joint (TMJ) and examine the results of conservative therapy administered to patients with SCs in the TMJ.

METHODS

The study included 41 patients with SCs, extracted from 684 consecutive patients who underwent magnetic resonance imaging (MRI). The anatomical features of SCs and positional abnormalities of the articular disc were initially evaluated using MRI. A second MRI examination was performed for 28/41 patients at 40-107 months (mean, 66 months) after the first MRI. The joint space, anteroposterior width of the condylar head (WiC), articular eminence angle (AEA), and visual analog scale of jaw pain (VAS) were assessed alongside the MRI examinations.

RESULTS

Most SCs were present in the anterosuperior and central condyle. Disc displacement was observed in 100% of 42 TMJs with SCs. Of the 29 joints in 28 patients, SCs in 19 joints resolved with time, whereas SCs in 10 joints persisted. A significant increase in the WiC and a significant decrease in AEA and VAS scores were observed on the second MRI scan.

CONCLUSIONS

SCs tended to form in the anterosuperior and central parts of the condyle, where mechanical loading was likely to be applied. SCs are strongly associated with articular disc displacement. Two-thirds of SCs resolved over time, accompanied by resorption and osteophytic deformation of the condyle. SC might not be an indicator for the start of surgical treatment, and nonsurgical treatment could improve the clinical symptoms of patients with SCs.

Causal associations of obesity related anthropometric indicators and body compositions with knee and hip arthritis: A large-scale genetic correlation study

Backgrounds

Epidemiological studies have repeatedly investigated the association between obesity related anthropometric indicators and body compositions and osteoarthritis (OA). However, the results have remained inconsistent. This work aimed to investigate the genetic correlation and causal associations of obesity related anthropometric indicators and body compositions with knee and hip OA.

Methods

Single-nucleotide polymorphisms associated with the exposures were searched from the recent genome-wide association studies (GWAS) to obtain full statistics. Summary-level results of knee and hip OA were from the UK Biobank and arcOGEN. First, linkage disequilibrium score regression (LD score regression) was applied to detect the genetic correlation (rg). We further performed a series of sensitivity analyses as validation of primary mendelian randomization (MR) results and the specific evidence of potential causal effects was defined.

Results

We found that genetic components in OA had significant correlation with obesity related traits, except waist-to-hip ratio. In the univariable MR analysis, with the exception of waist-to-hip ratio, obesity related anthropometric indicators were causally associated with increased risks of knee and hip OA. For obesity related body compositions, higher fat-free mass in arm, leg, and whole body increased the risk of knee OA but only fat-free mass in leg showed a significant association with hip OA. Meanwhile trunk fat mass and trunk fat percentage, were associated with knee but not with hip OA. Higher fat mass, and fat percentage in arm, leg, and whole body increased the risk of both knee and hip OA. After adjusting for BMI, the multivariable MR showed maintained results in knee OA. However, in hip OA, only fat mass and fat-free mass in arm, leg, trunk and whole body were significantly associated with the risk of hip OA.

Conclusion

The present study suggests genetic evidence for certain causal associations of obesity related anthropometric indicators and body compositions with knee and hip OA, which may provide important insights for the prevention and treatment on OA.

Role of adiponectin in osteoarthritis

Osteoarthritis (OA) is a widespread and most common joint disease which leads to social cost increasing accompany with aging population. Surgery is often the final treatment option. The major progression of OA includes cartilage degradation caused by chondrocytes metabolism imbalance. So, the molecular mechanisms of action in chondrocytes may provide insights into treatment methods for OA. Adiponectin is an adipokine with many biological functions in the cell metabolism. Numerous studies have illustrated that adiponectin has diverse biological effects, such as inhibition of cell apoptosis. It regulates various functions in different organs, including muscle, adipose tissue, brain, and bone, and regulates skeletal homeostasis. However, the relationship between adiponectin and cell death in the progression of OA needs further investigation. We elaborate the structure and function and the effect of adiponectin and state the correlation and intersection between adiponectin, autophagy, inflammation, and OA. From the perspective of oxidative stress, apoptosis, pyroptosis, and autophagy, we discuss the possible association between adiponectin, chondrocyte metabolism, and inflammatory factor efforts in OA. What’s more, we summarize the possible treatment methods, including the use of adiponectin as a drug target, and highlight the potential future mechanistic research. In this review, we summarize the molecular pathways and mechanisms of action of adiponectin in chondrocyte inflammation and death and the pathogenesis of OA. We also review the research on adiponectin as a target for treating OA. These studies provide a novel perspective to explore more effective treatment options considering the complex interrelationship between inflammation and metabolism in OA.

Pathological phenotypes of body composition in patients with rheumatic diseases

Aim – to identify the frequency of isolated and combined pathological phenotypes of body composition in women with rheumatic diseases and to determine the factors associated with the sarcopenic phenotype.

Materials and methods. 255 women (median age 60 [54; 64] years) were included in the study: 114 patients with rheumatoid arthritis (RA), 46 – with systemic sclerosis (SSc), 56 – with osteoarthritis (OA), and 39 persons without rheumatic diseases (control). Questionnaires, anthropometric measurements, double-energy X-ray absorptiometry of the whole body, lumbar spine and proximal femur were performed. The assessment of the factors associated with the sarcopenic phenotype was carried out using a univariate regression analysis.

Results. The frequency of isolated and combined pathological phenotypes in women with SSc was 34.8% and 52.2%, with RA – 51.8% and 38.6%, with OA – 71.4% and 10.7%, respectively. The sarcopenic phenotype was more often determined in patients with SSc (43.5%) and RA (29.8%) compared with women with OA (1.8%) (p<0.001). The factors associated with the sarcopenic phenotype were BMI><25 kg/m2 (OR=7.89 [95% CI: 3.90–15.96]; p><0.001), glucocorticoids (GC) intake (OR=2.50 [95% CI: 1.32–4.73]; p=0.005) and cumulative GC dose (OR=1.04 [95% CI: 1.01–1.07]; p=0.008), presence of osteoporosis (OP) (OR=4.31 [95% CI: 2.33–7.97]; p><0.001), leukocytosis more than 9.0×109 /l (OR=4.08 [95% CI: 1.38–12.10]; p=0.011), total protein less than 65 g/l (OR=1.11 [95% CI: 1.02–1.19]; p=0.019) and calcium intake less than 500 mg/day (OR=2.78 [95% CI: 1.39–5.53]; p=0.004). Conclusion. The study demonstrated a significant frequency of pathological phenotypes of body composition in women with rheumatic diseases, while combined phenotypes were more common in patients with SSc and RA compared with patients with OA. The probability of sarcopenic phenotype increased with BMI><25 kg/m2 , GC using, the presence of OP and insufficiency of calcium intake. Key words: rheumatic diseases, body composition phenotypes, sarcopenia, osteoporosis, osteosarcopenia, overfat, rheumatoid arthritis, systemic scleroderma, osteoarthritis, risk factors>˂ 0.001). The factors associated with the sarcopenic phenotype were BMI<25 kg/m2 (OR=7.89 [95% CI: 3.90–15.96];>˂ 25 kg/m2 (OR=7.89 [95% CI: 3.90–15.96]; p<0.001), glucocorticoids (GC) intake (OR=2.50 [95% CI: 1.32–4.73]; p=0.005) and cumulative GC dose (OR=1.04 [95% CI: 1.01–1.07]; p=0.008), presence of osteoporosis (OP) (OR=4.31 [95% CI: 2.33–7.97]; p><0.001), leukocytosis more than 9.0×109 /l (OR=4.08 [95% CI: 1.38–12.10]; p=0.011), total protein less than 65 g/l (OR=1.11 [95% CI: 1.02–1.19]; p=0.019) and calcium intake less than 500 mg/day (OR=2.78 [95% CI: 1.39–5.53]; p=0.004). Conclusion. The study demonstrated a significant frequency of pathological phenotypes of body composition in women with rheumatic diseases, while combined phenotypes were more common in patients with SSc and RA compared with patients with OA. The probability of sarcopenic phenotype increased with BMI><25 kg/m2 , GC using, the presence of OP and insufficiency of calcium intake. Key words: rheumatic diseases, body composition phenotypes, sarcopenia, osteoporosis, osteosarcopenia, overfat, rheumatoid arthritis, systemic scleroderma, osteoarthritis, risk factors>˂ 0.001), glucocorticoids (GC) intake (OR=2.50 [95% CI: 1.32–4.73]; p=0.005) and cumulative GC dose (OR=1.04 [95% CI: 1.01–1.07]; p=0.008), presence of osteoporosis (OP) (OR=4.31 [95% CI: 2.33–7.97]; p<0.001), leukocytosis more than 9.0×109 /l (OR=4.08 [95% CI: 1.38–12.10]; p=0.011), total protein less than 65 g/l (OR=1.11 [95% CI: 1.02–1.19]; p=0.019) and calcium intake less than 500 mg/day (OR=2.78 [95% CI: 1.39–5.53]; p=0.004).>˂ 0.001), leukocytosis more than 9.0×109 /l (OR=4.08 [95% CI: 1.38–12.10]; p=0.011), total protein less than 65 g/l (OR=1.11 [95% CI: 1.02–1.19]; p=0.019) and calcium intake less than 500 mg/day (OR=2.78 [95% CI: 1.39–5.53]; p=0.004).

Conclusion. The study demonstrated a significant frequency of pathological phenotypes of body composition in women with rheumatic diseases, while combined phenotypes were more common in patients with SSc and RA compared with patients with OA. The probability of sarcopenic phenotype increased with BMI<25 kg/m2 , GC using, the presence of OP and insufficiency of calcium intake. Key words: rheumatic diseases, body composition phenotypes, sarcopenia, osteoporosis, osteosarcopenia, overfat, rheumatoid arthritis, systemic scleroderma, osteoarthritis, risk factors>˂ 25 kg/m2, GC using, the presence of OP and insufficiency of calcium intake. 

Effects of sarcopenia and sarcopenic obesity on joint pain and degenerative osteoarthritis in postmenopausal women

This study aimed to identify the prevalence of sarcopenia, obesity, and sarcopenic obesity and examine their association with radiographic knee osteoarthritis (OA) and knee pain in Korean postmenopausal women. This cross-sectional study utilized the data from Korean National Health and Nutrition Examination Surveys 2009–2011. The participants were categorized into 4 groups based on body composition: either sarcopenic (appendicular skeletal muscle < 23%) or not, either obese (body mass index ≥ 25.0 kg/m²) or not. The prevalence of radiographic knee OA and knee pain was calculated. The effect of hormone replacement therapy (HRT) was also evaluated. The prevalence of radiographic knee OA, knee pain, and both were all highest in the sarcopenic obese group and lowest in the control group (61.49% vs. 41.54%, 39.11% vs. 27.55%, 32.04% vs. 17.82%, all p < 0.001). Without sarcopenia, obese women showed significantly higher ratio of radiographic knee OA only (57.64% vs. 41.54%, p < 0.001). With sarcopenia, the coexistence of obesity presented higher ratio of radiographic knee OA, knee pain, and both compared to sarcopenia without obesity (61.49% vs. 41.82%, 39.11% vs. 27.61%, 32.04% vs. 17.60%, all p < 0.001). The use of HRT for more than 1 year was not associated with radiographic knee OA, knee pain, or both (p = 0.147, 0.689 and 0.649, respectively). Obesity with sarcopenia had greater effect on knee OA compared to obesity without sarcopenia. Moreover, HRT use for more than 1 year was not associated with the prevalence of knee OA. Therefore, more efforts should focus on reducing body fat and increasing muscle in postmenopausal women with knee OA.

High prevalence of sarcopenia in Asian female patients awaiting primary total knee arthroplasty: Application of updated diagnostic tools from the Asian working group for sarcopenia

INTRODUCTION

Sarcopenia, a loss of muscle mass and strength with aging, is associated with various TKA-related complications. In 2020, the AWGS published an undated guideline (AWGS 2019) based on studies from East and Southeast Asia. The purpose of this study was to determine the prevalence of sarcopenia in Asian female patients awaiting primary total knee arthroplasty due to advanced knee osteoarthritis using the updated AWGS criteria.

MATERIALS AND METHODS

The present study included 138 female patients who scheduled for primary TKA with severe osteoarthritis. The included patients were assessed with use of an AWGS 2019 diagnostic criteria based on muscle strength, physical performance, and appendicular skeletal muscle mass. Clinical parameters related to sarcopenia were collected and knee status assessed using the Knee Society scoring system. To better define the association with age, patients were stratified into following four groups: <60, 60-69, 70-79, ≥80. The prevalence of sarcopenia was identified, and the association between sarcopenia and clinical variables was analyzed.

RESULTS

The prevalence of sarcopenia and severe sarcopenia in this cohort according to the updated AWGS criteria was 35.5% and 21.7%. Prevalence of sarcopenia and severe sarcopenia significantly increased with advancing age (p = .003, p = .040, respectively). Although not statistically significant, the proportion of severe sarcopenia among sarcopenia also increased with age. Multivariate logistic regression analysis revealed that lower BMI and lower 25-OH-vitamin D3 level were independent risk factors associated with sarcopenia in women awaiting TKA.

CONCLUSIONS

In conclusion, our study confirmed that sarcopenia is more prominent amongst female patients awaiting primary TKA than the general population. Therefore, orthopedic surgeons should consider sarcopenia prevention and intervention in this group. Further studies are needed to investigate the effect of TKA on sarcopenia, and the difference of TKA outcomes between groups with or without underlying sarcopenia.

Association between sarcopenia and osteoarthritis: A protocol for meta-analysis

Background

Sarcopenia, a relatively new syndrome referring to the age-related decline of muscle strength and degenerative loss of skeletal muscle mass and function, often resulting in frailty, disability, and mortality. Osteoarthritis, as a prevalent joint degenerative disease, is affecting over 250 million patients worldwide, and it is the fifth leading cause of disability. Despite the high prevalence of osteoarthritis, there are still lack of efficient treatment potions in clinics, partially due to the heterogeneous and complexity of osteoarthritis pathology. Previous studies revealed the association between sarcopenia and osteoarthritis, but the conclusions remain controversial and the prevalence of sarcopenia within osteoarthritis patients still needs to be elucidated. To identify the current evidence on the prevalence of sarcopenia and its association with osteoarthritis across studies, we performed this systematic review and meta-analysis that would help us to further confirm the association between these two diseases.

Methods and analysis

Electronic sources including PubMed, Embase, and Web of Science will be searched systematically following appropriate strategies to identify relevant studies from inception up to 28 February 2022 with no language restriction. Two investigators will evaluate the preselected studies independently for inclusion, data extraction and quality assessment using a standardized protocol. Meta-analysis will be performed to pool the estimated effect using studies assessing an association between sarcopenia and osteoarthritis. Subgroup analyses will also be performed when data are sufficient. Heterogeneity and publication bias of included studies will be investigated.

PROSPERO registration number

CRD42020155694.

Apostol Andrei’, Constanta, Romania, 4 Department, Faculty of Medicine, ‘Ovidius’ University of Constanta, Department of medico-surgical and prophylactic disciplines, Titu Maiorescu University, Bucharest, Romania, Department of Infectious Diseases, Carol Davila University Central Emergency Military Hospital, Bucharest, Romania. Gut microbiota and obesity

Worldwide, adults and childhood obesity are increasing alarmingly, being a major health problem. Obesity is correlated with an increased incidence of various systemic diseases including cancer, heart diseases, and diabetes mellitus type 2. Risk factors for obesity are dysbiosis, genetic, socioeconomic, behavioural and environmental. The gut microbiota has beneficial effects on human health, like host immune system stimulation, being influenced by pH, or nutrient intake. Studies performed on humans and animal models reported differences regarding microbiota at lean and obese individuals. The consumption of probiotics and prebiotics may balance the microbiota with positive effects in obesity. The main aim of this review is to reveal the interaction between dysbiosis and obesity

Senescent preosteoclast secretome promotes metabolic syndrome associated osteoarthritis through cyclooxygenase 2

Background

Metabolic syndrome-associated osteoarthritis (MetS-OA) is a distinct osteoarthritis phenotype defined by the coexistence of MetS or its individual components. Despite the high prevalence of MetS-OA, its pathogenic mechanisms are unclear. The aim of this study was to determine the role of cellular senescence in the development of MetS-OA.

Methods

Analysis of the human osteoarthritis initiative (OAI) dataset was conducted to investigate the MRI subchondral bone features of MetS-human OA participants. Joint phenotype and senescent cells were evaluated in two MetS-OA mouse models: high-fat diet (HFD)-challenged mice and STR/Ort mice. In addition, the molecular mechanisms by which preosteoclasts become senescent as well as how the senescent preosteoclasts impair subchondral bone microenvironment were characterized using in vitro preosteoclast culture system.

Results

Humans and mice with MetS are more likely to develop osteoarthritis-related subchondral bone alterations than those without MetS. MetS-OA mice exhibited a rapid increase in joint subchondral bone plate and trabecular thickness before articular cartilage degeneration. Subchondral preosteoclasts undergo senescence at the pre- or early-osteoarthritis stage and acquire a unique secretome to stimulate osteoblast differentiation and inhibit osteoclast differentiation. Antagonizing preosteoclast senescence markedly mitigates pathological subchondral alterations and osteoarthritis progression in MetS-OA mice. At the molecular level, preosteoclast secretome activates COX2-PGE2, resulting in stimulated differentiation of osteoblast progenitors for subchondral bone formation. Administration of a selective COX2 inhibitor attenuated subchondral bone alteration and osteoarthritis progression in MetS-OA mice. Longitudinal analyses of the human Osteoarthritis Initiative (OAI) cohort dataset also revealed that COX2 inhibitor use, relative to non-selective nonsteroidal antiinflammatory drug use, is associated with less progression of osteoarthritis and subchondral bone marrow lesion worsening in participants with MetS-OA.

Conclusions

Our findings suggest a central role of a senescent preosteoclast secretome-COX2/PGE2 axis in the pathogenesis of MetS-OA, in which selective COX2 inhibitors may have disease-modifying potential.

Funding

This work was supported by the National Institutes of Health grant R01AG068226 and R01AG072090 to MW, R01AR079620 to SD, and P01AG066603 to XC.

Biomaterial-Based Therapeutic Approaches to Osteoarthritis and Cartilage Repair Through Macrophage Polarization

There is an ever-increasing clinical and socioeconomic burden associated with cartilage lesions & osteoarthritis (OA). Its progression, chondrocyte death & hypertrophy are all facilitated by inflamed synovium & joint environment. Due to their capacity to switch between pro- & anti-inflammatory phenotypes, macrophages are increasingly being recognized as a key player in the healing process, which has been largely overlooked in the past. A biomaterial's inertness has traditionally been a goal while developing them in order to reduce the likelihood of adverse reactions from the host organism. A better knowledge of how macrophages respond to implanted materials has made it feasible to determine the biomaterial architectural parameters that control the host response & aid in effective tissue integration. Thus, this review summarizes novel therapeutic techniques for avoiding OA or increasing cartilage repair & regeneration that might be developed using new technologies tuning macrophages into desirable functional phenotypes.

The Burden of Osteoarthritis in the Middle East and North Africa Region From 1990 to 2019

Objective

We aimed to report the most current data on the prevalence, incidence, and years lived with disability (YLDs) associated with osteoarthritis (OA) for the 21 countries and territories located in the Middle East and North Africa (MENA) region from 1990 to 2019 by age, sex, cause, and sociodemographic index (SDI).

Methods

Publicly available data from the Global Burden of Disease 2019 study were used to report the OA-related burden. Estimates are reported as counts and age-standardized rates, along with their corresponding 95% uncertainty intervals (UIs).

Results

In 2019, the age-standardized prevalence of OA in MENA was 5,342.8 per 100,000 (95% UI: 4,815.9–5,907.8), which is 9.3% higher than in 1990 (8.1–10.5%). Similarly, the age-standardized annual incidence of OA per 100,000 was 430.4 (382.2–481.9), demonstrating a 9.4% increase since 1990 (8.3–10.5). OA was the cause of 185.4 (92.8–370.2) age-standardized YLDs per 100,000 in 2019, which was 10% higher than in 1990 (8.7–11.4). Saudi Arabia, Kuwait, and Iran had the highest OA burden in MENA, while Yemen, Afghanistan, and Sudan had the lowest burden. In all MENA countries, OA affected more women than men, had an increasing burden with increased age, and had the highest impact on the knee, hip, and hand joints, respectively. OA was also positively associated with the SDI.

Conclusion

The burden of OA increased over 1990–2019 in the MENA region. The study emphasizes the importance of early preventative approaches in order to control any future health, economic, and quality of life crises imposed by OA in this region.

Secular Difference in Body Mass Index From 2014 to 2020 in Chinese Older Adults: A Time-Series Cross-Sectional Study

Background

Body mass index (BMI) is the most widely used parameter to assess the body weight status. Both the increase of BMI (overweight and obesity) and decrease of BMI (underweight) has been associated with high risk of adverse outcome, such as stroke, disability, and even death. However, recent data on secular differences in BMI in the Chinese aged population are limited. The present study provides robust new evidence about the evolving epidemic of obesity among aged adults in China.

Objective

Evaluating secular difference in BMI in a group of Chinese older adults.

Materials and Methods

We analyzed 7 continuous survey years (2014–2020), including 50,192 Chinese aged participants (25,505 men and 24,687 women, aged 71.9 ± 6.1 years, age range: 65–99 years). Information on sex, age, height, and body weight, was collected based on medical history. Participants were classified into four groups: underweight (BMI &lt; 18.5 kg/m2), normal weight (18.5 kg/m2 ≤ BMI &lt; 25 kg/m2), overweight (25 kg/m2 ≤ BMI &lt; 30 kg/m2), and obesity (BMI ≥ 30 kg/m2). Linear regressions were used to assess the secular difference in BMI. Sex and age differences were also evaluated by stratified analyses.

Results

From 2014 to 2020, age-adjusted mean BMI increased by 0.3 kg/m2 (95% CI: 0.1, 0.5 kg/m2) in men, and 0.5 kg/m2 (95% CI: 0.2, 0.7 kg/m2) in women. Age-standardized prevalence of underweight decreased from 3.0 to 2.3% in men, and from 3.0 to 2.1% in women. Age-standardized prevalence of overweight increased in both men (from 40.1 to 41.7%) and women (from 37.8 to 39.8%), and so as obesity (men: from 4.1 to 6.1%; women: from 5.8 to 8.7%).

Conclusion

Our results confirmed that BMI gradually increased from 2014 to 2020. The age-adjusted mean BMI increased by 0.3 kg/m2 in older men, and 0.5 kg/m2 in older women. The age- and sex-standardized prevalence of overweight and obesity significantly increased, especially in 70–79-year age group, while the prevalence of underweight decreased. The combination of a balanced-diet and physical exercise is needed to maintain optimal BMI range for the aged population.

Mass spectrometry-based proteomics identify novel serum osteoarthritis biomarkers

Background

Osteoarthritis (OA) is a slowly developing and debilitating disease, and there are no validated specific biomarkers for its early detection. To improve therapeutic approaches, identification of specific molecules/biomarkers enabling early determination of this disease is needed. This study aimed at identifying, with the use of proteomics/mass spectrometry, novel OA-specific serum biomarkers. As obesity is a major risk factor for OA, we discriminated obesity-regulated proteins to target only OA-specific proteins as biomarkers.

Methods

Serum from the Osteoarthritis Initiative cohort was used and divided into 3 groups: controls (n=8), OA-obese (n=10) and OA-non-obese (n=10). Proteins were identified and quantified from the liquid chromatography–tandem mass spectrometry analyses using MaxQuant software. Statistical analysis used the Limma test followed by the Benjamini-Hochberg method. To compare the proteomic profiles, the multivariate unsupervised principal component analysis (PCA) followed by the pairwise comparison was used. To select the most predictive/discriminative features, the supervised linear classification model sparse partial least squares regression discriminant analysis (sPLS-DA) was employed. Validation of three differential proteins was performed with protein-specific assays using plasma from a cohort derived from the Newfoundland Osteoarthritis.

Results

In total, 509 proteins were identified, and 279 proteins were quantified. PCA-pairwise differential comparisons between the 3 groups revealed that 8 proteins were differentially regulated between the OA-obese and/or OA-non-obese with controls. Further experiments using the sPLS-DA revealed two components discriminating OA from controls (component 1, 9 proteins), and OA-obese from OA-non-obese (component 2, 23 proteins). Proteins from component 2 were considered related to obesity. In component 1, compared to controls, 7 proteins were significantly upregulated by both OA groups and 2 by the OA-obese. Among upregulated proteins from both OA groups, some of them alone would not be a suitable choice as specific OA biomarkers due to their rather non-specific role or their strong link to other pathological conditions. Altogether, data revealed that the protein CRTAC1 appears to be a strong OA biomarker candidate. Other potential new biomarker candidates are the proteins FBN1, VDBP, and possibly SERPINF1. Validation experiments revealed statistical differences between controls and OA for FBN1 (p=0.044) and VDPB (p=0.022), and a trend for SERPINF1 (p=0.064).

Conclusion

Our study suggests that 4 proteins, CRTAC1, FBN1, VDBP, and possibly SERPINF1, warrant further investigation as potential new biomarker candidates for the whole OA population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02801-1.

The prevalence of osteoarthritis and its association with geriatric syndromes in people over 65: data from the Russian epidemiological study EVKALIPT

Background. Osteoarthritis (OA) in elderly and senile patients is not only common, but also one of the main diseases affecting the duration of active life, its quality, the appearance of addictions and loss of autonomy. Data on the relationship between OA and geriatric syndromes (GS) in our country are extremely scarce. Aim. To estimate the prevalence of OA and to analyze its associations with HS in persons aged 65 years. Materials and methods. The study included 4308 people (30% of men) aged 65 to 107 years, living in 11 regions of Russia. The patients were divided into 2 groups: with OA (n=2464) and without OA (n=1821). All patients underwent a comprehensive geriatric assessment. Results. The prevalence of OA was 57.6%. With age, the frequency of OA increased significantly. According to the results of a comprehensive geriatric assessment, patients with OA had lower walking speed, the sum of points on the Bartel, Lawton scales and a short battery of physical functioning tests and higher the sum of points on the geriatric scale of depression and the age is not a hindrance scale. Patients with OA rated the quality of life and health status lower and higher the intensity of pain syndrome. Patients with OA were more likely to use any assistive device, with the exception of a wheelchair. In patients with OA, the most common HS were chronic pain syndrome (92%), senile asthenia syndrome (64%), basic (66%) and instrumental (56%) dependence in everyday life, cognitive impairment (62%), probable depression (51%) and urinary incontinence (50%). Univariate regression analysis showed that OA is associated with a 1.23.0-fold increase in the risk of a number of GS and a 28% decrease in the risk of malnutrition. Conclusion. OA is widespread in the elderly population. The presence of OA is associated with a number of GS associated with loss of autonomy.

The Impact of Trace Elements on Osteoarthritis

Osteoarthritis (OA) is a progressive degenerative disease characterized by cartilage degradation, synovial inflammation, subchondral sclerosis and osteophyte formation. It has a multifactorial etiology with potential contributions from heredity, endocrine function, abnormal mechanical load and nutrition. Of particular considerations are trace element status. Several trace elements, such as boron and magnesium are essential for normal development of the bone and joint in human. While cadmium correlates with the severity of OA. The present review focuses on the roles of trace elements (boron, cadmium, copper, iron, magnesium, manganese, selenium, zinc) in OA and explores the mechanisms by which they act.

Is there a relationship between hand grip strength and knee osteoarthritis in terms of radiological and functional findings in female patients?

Objectives

The aim of this study was to assess the presence of the relationship between hand grip strength (HGS) and radiological and functional signs of knee osteoarthritis (KOA).

Patients and methods

Between March 2019 and January 2020, a total of 64 female patients (mean age: 63.4±8.8 years; range, 50 to 80 years) with bilateral chronic knee pain who were diagnosed with KOA using radiological and clinical findings according to the 2019 American College of Rheumatology guidelines were included in the study. Patient demographics, body mass index (BMI) values, and hand dominance were recorded. The Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Lower Extremity Functional Scale (LEFS) were used for the assessment of KOA functionality. The Kellgren-Lawrence (KL) grading system was used for the radiological assessment of KOA. Electronic dynamometer was used for HGS measurement and values were normalized according to BMI results.

Results

In the assessment of relationship between HGS and functionality of KOA, a negative, moderate correlation was found between the WOMAC and HGS-Dominant (D) (r=0.312, p<0.05) and HGS-Non-Dominant (ND) (r=0.391, p<0.01). In addition, a positive, moderate correlation was found between the LEFS and HGS-D (r=0.344, p<0.01) and HGS-ND (r=0.371, p<0.01). There was a weak, negative correlation between the HGS-ND, KL-D (r=0.256, p<0.05) and KL-ND (r=0.283, p<0.05), while no significant correlation was found between the HGS-D and KL.

Conclusion

Our study results show that HGS-ND is associated with KOA radiologically and functionally. The HGS should be added in the WOMAC and LEFS scales in the functional assessment of KOA and new scales including HGS assessment should be developed.

Effects of Sarcopenic Obesity and Its Confounders on Knee Range of Motion Outcome after Total Knee Replacement in Older Adults with Knee Osteoarthritis: A Retrospective Study

Sarcopenic obesity is closely associated with knee osteoarthritis (KOA) and has high risk of total knee replacement (TKR). In addition, poor nutrition status may lead to sarcopenia and physical frailty in KOA and is negatively associated with surgery outcome after TKR. This study investigated the effects of sarcopenic obesity and its confounding factors on recovery in range of motion (ROM) after total knee replacement (TKR) in older adults with KOA. A total of 587 older adults, aged ≥60 years, who had a diagnosis of KOA and underwent TKR, were enrolled in this retrospective cohort study. Sarcopenia and obesity were defined based on cutoff values of appendicular mass index and body mass index for Asian people. Based on the sarcopenia and obesity definitions, patients were classified into three body-composition groups before TKR: sarcopenic-obese, obese, and non-obese. All patients were asked to attend postoperative outpatient follow-up admissions. Knee flexion ROM was measured before and after surgery. A ROM cutoff of 125 degrees was used to identify poor recovery post-surgery. Kaplan-Meier curve analysis was performed to measure the probability of poor ROM recovery among study groups. Cox multivariate regression models were established to calculate the hazard ratios (HRs) of postoperative poor ROM recovery, using potential confounding factors including age, sex, comorbidity, risk of malnutrition, preoperative ROM, and outpatient follow-up duration as covariates. Analyses results showed that patients in the obese and sarcopenic-obese groups had a higher probability of poor ROM recovery compared to the non-obese group (all p < 0.001). Among all body-composition groups, the sarcopenic-obese group yielded the highest risk of postoperative physical difficulty (adjusted HR = 1.63, p = 0.03), independent to the potential confounding factors. Sarcopenic obesity is likely at the high risk of poor ROM outcome following TKR in older individuals with KOA.

Targeted treatment for osteoarthritis: drugs and delivery system

The management of osteoarthritis (OA) is a clinical challenge due to the particular avascular, dense, and occluded tissue structure. Despite numerous clinical reports and animal studies, the pathogenesis and progression of OA are still not fully understood. On the basis of traditional drugs, a large number of new drugs have been continuously developed. Intra-articular (IA) administration for OA hastens the development of targeted drug delivery systems (DDS). OA drugs modification and the synthesis of bioadaptive carriers contribute to a qualitative leap in the efficacy of IA treatment. Nanoparticles (NPs) are demonstrated credible improvement of drug penetration and retention in OA. Targeted nanomaterial delivery systems show the prominent biocompatibility and drug loading-release ability. This article reviews different drugs and nanomaterial delivery systems for IA treatment of OA, in an attempt to resolve the inconsonance between in vitro and in vivo release, and explore more interactions between drugs and nanocarriers, so as to open up new horizons for the treatment of OA.

Incidence and risk factors analysis for mortality after total knee arthroplasty based on a large national database in Korea

This study aimed to analyze the rates and risk factors of postoperative mortality among 560,954 patients who underwent total knee arthroplasty (TKA) in Korea. The National Health Insurance Service-Health Screening database was used to analyze 560,954 patients who underwent TKA between 2005 and 2018. In-hospital, ninety-day, and one-year postoperative mortality, and their association with patient’s demographic factors and various comorbidities (ie., cerebrovascular disease, congestive heart failure, and myocardial infarction) were assessed. In-hospital, ninety-day and one-year mortality rates after TKA were similar from 2005 to 2018. The risk of in-hospital mortality increased with comorbidities like cerebrovascular disease (hazard ratio [HR] = 1.401; 95% confidence interval [CI] = 1.064–1.844), congestive heart failure (HR = 2.004; 95% CI = 1.394 to 2.881), myocardial infarction (HR = 2.111; 95% CI = 1.115 to 3.998), and renal disease (HR = 2.641; 95% CI = 1.348–5.173). These co-morbidities were also independent predictors of ninety-day and one-year mortality. Male sex and old age were independent predictors for ninety-day and one-year mortality. And malignancy was risk factor for one-year mortality. The common preoperative risk factors for mortality in all periods were male sex, old age, cerebrovascular disease, congestive heart failure, myocardial infarction, and renal disease. Malignancy was identified as risk factor for one-year mortality. Patients with these comorbidities should be provided better perioperative care.

Appendicular Lean Mass, Grip Strength, and the Development of Knee Osteoarthritis and Knee Pain Among Older Adults

Objective

The association of sarcopenia with development of knee osteoarthritis (OA) or knee pain in older adults is uncertain. We examined the relationship of grip strength and appendicular lean mass (ALM) with the likelihood of developing knee OA and knee pain in older adults in the Health ABC (Health, Aging, and Body Composition) Study.

Methods

ALM and grip strength were assessed at baseline by dual‐energy x‐ray absorptiometry and handheld dynamometry, respectively. Incident clinically diagnosed, symptomatic knee OA, defined as new participant report of physician‐diagnosed knee OA and concurrent frequent knee pain, and incident frequent knee pain over 5 years of follow‐up were examined. Separate regression analyses, stratified by sex, modeled associations of baseline ALM and grip strength with the likelihood of incident clinically diagnosed, symptomatic knee OA and incident knee pain over follow‐up, adjusting for covariates.

Results

Among the 2779 subjects without OA at baseline, 95 men (6.9%) and 158 women (11.3%) developed clinically diagnosed, symptomatic knee OA, and, among the 2182 subjects without knee pain at baseline, 315 men (28.3%) and 385 women (36.1%) developed knee pain over follow‐up. Among men only, each SD decrement of ALM was associated with decreasing likelihood of incident knee OA (odds ratio [OR] per SD decrement: 0.68; 95% confidence interval [CI]: 0.47‐0.97), and each SD decrement of grip strength was associated with increasing likelihood of incident knee pain (OR per SD decrement: 1.20; 95% CI: 1.01‐1.42).

Conclusion

In older men, ALM and grip strength may be associated with the development of knee OA and knee pain, respectively.

Relative Efficacy of Weight Management, Exercise, and Combined Treatment for Muscle Mass and Physical Sarcopenia Indices in Adults with Overweight or Obesity and Osteoarthritis: A Network Meta-Analysis of Randomized Controlled Trials

Aging and osteoarthritis are associated with high risk of muscle mass loss, which leads to physical disability; this loss can be effectively alleviated by diet (DI) and exercise (ET) interventions. This study investigated the relative effects of different types of diet, exercise, and combined treatment (DI+ET) on muscle mass and functional outcomes in individuals with obesity and lower-limb osteoarthritis. A comprehensive search of online databases was performed to identify randomized controlled trials (RCTs) examining the efficacy of DI, ET, and DI+ET in patients with obesity and lower-extremity osteoarthritis. The included RCTs were analyzed through network meta-analysis and risk-of-bias assessment. We finally included 34 RCTs with a median (range/total) Physiotherapy Evidence Database score of 6.5 (4-8/10). DI plus resistance ET, resistance ET alone, and aerobic ET alone were ranked as the most effective treatments for increasing muscle mass (standard mean difference (SMD) = 1.40), muscle strength (SMD = 1.93), and walking speed (SMD = 0.46). Our findings suggest that DI+ET is beneficial overall for muscle mass in overweight or obese adults with lower-limb osteoarthritis, especially those who are undergoing weight management.