Obesity is considered an important risk factor for osteoarthritis (OA), with conicity index (C-index), relative fat mass (RFM) are two novel anthropometric measures of obesity. To investigate the association between OA and these two indicators, we conducted this study.

We used data from the National Health and Nutrition Examination Survey (NHANES) to investigate the association between C-index, RFM, and OA. First, the participants were divided into two groups according to whether they had OA, and we compared the baseline characteristics of the two groups. Then, C-index and RFM were divided into quartiles (Q1, Q2, Q3, Q4) for multivariate regression analysis. Additionally, we applied restricted cubic spline (RCS) to assess whether the relationship is non-linear. Finally, we conducted a subgroup interaction analysis to investigate whether this relationship varies across different subgroups.

The study included 34,707 participants, with a weighted OA prevalence of 7.7%. Significant differences in C-index and RFM were observed between OA and non-OA groups. Treating C-index and RFM as categorical variables, logistic regression showed significantly higher OA risk in Q4 compared to Q1: for C-index, Q4 (OR = 1.60; 95% CI: 1.33-1.93; P < 0.001); for RFM, Q4 (OR = 2.07; 95% CI: 1.57-2.73; P < 0.001). The RCS results show that the relationship between C-index and OA is non-linear, while the relationship between RFM and OA is linear. Subgroup interaction analysis showed some interaction effects.

This study reveals detailed relationships between C-index, RFM, and OA, which may be better indicators of obesity in assessing OA risk.

Knee osteoarthritis (KOA) is primarily characterized by joint pain and dysfunction, and KOA has increasingly emerged as a public health concern in China and globally. This study aims to utilize data from the Global Burden of Disease (GBD) 2021 to summarize the disease burden of KOA in China and globally from 1992 to 2021, while also predicting the disease burden in 2030.

Using data from the GBD 2021 study, we compared and described the burden of KOA in China and globally. Joinpoint regression was applied to assess long-term trends in the burden of KOA based on GBD 2021 data. The impact of population growth, aging, and epidemiological trends on the burden of KOA was examined through decomposition analysis. Additionally, an age-period-cohort analysis (APC) was conducted to assess the effects of age, period, and cohort on the burden of KOA in China. Finally, we predicted the burden of KOA in 2030 using the Bayesian age-period-cohort (BAPC) and Norpred models.

In 2021, the number of patients with KOA in China was 10,957,472, reflecting an increase of 157.15% compared to 1992. Similarly, the incidence of KOA in China for the same year was 8,512,396, representing a rise of 123.45% since 1992. The and Years lived of disabled (YLDs) rate for KOA in China was 249.81 per 100,000 population, which is 116.44% higher than the rate observed in 1992. In 2021, the prevalence of KOA increased with age. Female exhibited higher estimates of prevalence, incidence, and YLDs than male across all age groups. Joinpoint regression analysis revealed fluctuating upward trends in prevalence, incidence, and YLDs, from 1992 to 2021. Decomposition analysis identified population growth as the primary driver of increased prevalence, incidence, and YLDs, particularly among female. Projections indicate that the number of KOA YLDs in China will continue to rise, potentially reaching a peak by 2030.

The disease burden of KOA in China remains significant, necessitating increased attention, particularly for female and the middle-aged and older adult populations, in order to develop more targeted preventive measures.

Degenerative spine and joint diseases, including intervertebral disc degeneration (IDD), ossification of the spinal ligaments (OSL), and osteoarthritis (OA), are common musculoskeletal diseases that cause pain or disability to the patients. However, the pathogenesis of these musculoskeletal disorders is complex and has not been elucidated clearly to date. As a matter of fact, the spine and joints are not independent of other organs and tissues. Recently, accumulating evidence demonstrates the association between obesity and degenerative musculoskeletal diseases. Obesity is a common metabolic disease characterized by excessive adipose tissue or abnormal adipose distribution in the body. Excessive mechanical stress is regarded as a critical risk factor for obesity-related pathology. Additionally, obesity-related factors, mainly including lipid metabolism disorder, dysregulated pro-inflammatory adipokines and cytokines, are reported as plausible links between obesity and various human diseases. Importantly, these obesity-related factors are deeply involved in the regulation of cell phenotypes and cell fates, extracellular matrix (ECM) metabolism, and inflammation in the pathophysiological processes of degenerative spine and joint diseases. In this study, we systematically discuss the potential cellular and molecular mechanisms underlying obesity in these degenerative musculoskeletal diseases, and hope to provide novel insights for developing targeted therapeutic strategies.

Knee osteoarthritis (OA) is a common condition with a prevalence of 365 million individuals globally, and it is an independent risk factor for falls and fractures, notably asymptomatic morphometric vertebral fractures (AMVF). The high prevalence of knee OA, the severity of AMVF, and their combined impacts on quality of life underscore the need for early detection, appropriate treatment and management. To address this, our cross-sectional study aims to identify potential predictive factors associated with AMVF in knee OA patients. Our cohort consisted of 76 patients diagnosed with knee OA, predominantly female (84.2%), of Malay ethnicity (84.2%), and obese (55.3%). In univariable analysis, significant association was found between occupation (moderate or heavy work) and AMVF (p<0.001). Diabetes mellitus comorbidity (p = 0.016) and fat mass percentage (p = 0.027) also demonstrated a significant association with AMVF in knee OA patients. Multivariable logistic regression analysis revealed that an increase in fat mass percentage resulted in decreased AMVF incidence (HR: 0.83, 95% CI: 0.70-0.97; p = 0.018), while occupation (moderate or heavy work) remained a highly significant predictor (HR: 57.76, 95% CI: 4.23-788.57; p = 0.002). These findings support the potential importance of considering occupational activities and body fat composition in managing AMVF among knee OA patients, but further research is required to establish causal relationships.

In a randomized, controlled study, whole-body electromyostimulation (WB-EMS) was investigated as a promising alternative treatment technique compared to conventional strength training for the management of knee osteoarthritis (OA). Seventy-two overweight participants with symptomatic knee OA were randomly assigned to WB-EMS (n = 36) or a usual care group (UCG, n = 36). For seven months, the WB-EMS group received three times per fortnight a WB-EMS training, while the UCG was prescribed six-times physiotherapeutic treatments. We observed significant effects for the primary outcome "pain", as determined by the Knee injury and Osteoarthritis Outcome Score (KOOS), with more favourable changes in the WB-EMS group vs UCG (between-group difference 9.0 points, 95%CI 2.9-15.1, p = 0.004). Secondary outcomes, including the other KOOS subscales (symptoms, function in daily living, function in sports/recreational activities and quality of life), 7 day pain diary, hip/leg extensor strength and lower limb function (30s sit-to-stand test), were also statistically significant in favour of the WB-EMS group. Overall, WB-EMS was found to be effective in relieving knee pain symptoms and improving physical function in individuals with symptomatic knee OA compared to usual care treatment. WB-EMS could be used as an alternative therapy in the management of knee OA; particularly for patients that cannot be motivated for conventional training.

The aim of this study was to compare elbow joint proprioception measurements between physically disabled individuals who are active in sports and those who are not. The study included 30 athletes, 30 sedentary individuals, 30 physically disabled athletes, and 30 physically disabled sedentary individuals as volunteers. Elbow joint proprioception measurements were conducted using a sensitive digital goniometer with a precision of 1 degree. The joint position sense test method was used to perform the active angle repetition technique. Target angles were determined to be 30°, 60°, and 120°. A significant difference was observed in the comparison of proprioception between the dominant and non-dominant elbow joints of athletes and physically disabled sedentary individuals (p<0.05). Elbow joint proprioception was found to be highest in physically disabled athletes at the target angles. Conversely, the lowest elbow joint proprioception levels were found in physically disabled sedentary patients compared with the other groups.

Body weight has been recognized as a driving factor of osteoarthritis. Few studies had investigated the association between weight status across adulthood and risk of osteoarthritis (OA). This study investigates the association of weight change patterns across adulthood (lasting at least 25 years) with the risk of OA from the National Health and Nutrition Examination Survey (NHANES) 2013-2018.

The study assessed the relationship between weight change across adulthood and OA in 7392 individuals aged > 50 spanning a minimum of 25 years. Multivariate linear regression analyses were utilized to detect the association between weight change patterns and self-reported OA. Restricted cubic splines (RCS) were used to examine the nonlinear relationship between absolute weight change and OA risk.

From 10 years ago to survey, the risk of OA was 1.34-fold (95% CI 1.07-1.68) in people changed from obese to non-obese, 1.61-fold (95% CI 1.29-2.00) in people change from non-obese to obese, and 1.82-fold (95% CI 1.49-2.22) in stable obese people compared with people who were at stable normal weight. Similar patterns were also observed at age 25 years to baseline and age 25 years to 10 years before the baseline. The dose-response association of RCS found a U-shaped relationship between absolute weight change and OA risk.

The study suggests that weight patterns across adulthood are associated with the risk of OA. These findings stressed important to maintain a normal weight throughout adulthood, especially to prevent ignored weight gain in early adulthood to reduce OA risk later.

This study investigated whether the lower extremity muscle mass index (LMI) mediates the relationship between general obesity, central obesity, and knee osteoarthritis in middle-aged and elderly women in Korea.

Data of 2,843 women aged ≥50 years were collected from the Korean National Health and Nutrition Examination Survey conducted between 2009 and 2011. General obesity and central obesity were evaluated based on body mass index (BMI) and waist circumference (WC), calculated through anthropometric measurements and body composition assessments. LMI was calculated by dividing the muscle mass in both legs-measured using the dual-energy X-ray absorptiometry-by body weight. Knee osteoarthritis was defined as a Kellgren-Lawrence scale (KL) grade of ≥2 as assessed through radiographic images.

Knee osteoarthritis prevalence, indicated by KL grades, was significantly higher in the general obesity and central obesity groups compared to the normal group, and conversely, lower with varying LMI levels. Using mediation analysis with bootstrapping and adjusting for covariates, we found that LMI mediated the relationship between BMI and KL (β, 0.005; 95% confidence interval [CI], 0.000 to 0.010) and WC and KL grade (β, 0.002; 95% CI, 0.001 to 0.003), explaining 4.8% and 6.7% of the total effects of BMI and WC on KL grade, respectively.

The study suggested that LMI partially mediates the link between general obesity and/or central obesity and knee osteoarthritis, proposing that a higher proportion of lower limb muscle mass relative to body weight can alleviate the increased risk of knee osteoarthritis caused by obesity.

The objective of this study is to delineate disparities between patients with knee osteoarthritis (KOA) based on obesity status, investigate the interplay among body composition, physical activity and knee pain/function in patients with KOA and conduct subgroup analyses focusing on those with KOA and obesity.

Cross-sectional study.

Residents of eight communities in Shijiazhuang, Hebei Province, China, were surveyed from March 2021 to November 2021.

178 patients with symptomatic KOA aged 40 years or older were included.

The primary outcome measure was knee pain, assessed using the Western Ontario and McMaster Universities Osteoarthritis Index-pain (WOMAC-P) scale. Secondary outcome measures included function, evaluated through the WOMAC-function (WOMAC-F) scale and the Five-Time-Sit-to-Stand Test (FTSST). Data analysis involved t-tests, Wilcoxon rank-sum tests, χ2 tests, linear and logistical regression analysis.

Participants (n=178) were 41-80 years of age (median: 65, P25-P75: 58-70), and 82% were female. Obese patients (n=103) had worse knee pain and self-reported function (p<0.05). In general patients with KOA, body fat mass was positively associated with bilateral knee pain (β=1.21 (95% CI 0.03 to 0.15)), WOMAC-P scores (β=0.25 (95% CI 0.23 to 1.22)), WOMAC-F scores (β=0.28 (95% CI 0.35 to 1.29)) and FTSST (β=0.19 (95% CI 0.03 to 0.42)), moderate-intensity to low-intensity physical activity was negatively associated with bilateral knee pain (β=-0.80 (95% CI -0.10 to -0.01)) and Skeletal Muscle Index (SMI) was negatively associated with WOMAC-F scores (β=-0.16 (95% CI -0.66 to -0.03)). In patients with KOA and obesity, SMI was negatively associated with FTSST (β=-0.30 (95% CI -3.94 to -0.00)).

Patients with KOA and obesity had worse knee pain and self-reported function compared with non-obese patients. Greater fat mass, lower muscle mass and lower moderate-intensity to low-intensity physical activity were associated with increased knee pain and poor self-reported function. More skeletal muscle mass was associated with the improvement of objective function.

With the development of population aging worldwide, sarcopenia and knee osteoarthritis (KOA), two age-related diseases, will continue to impose increasing medical and economic burdens on the society. Previous studies have discovered an association between the two, but the causality remains controversial, and it is difficult to eliminate confounding factors. Therefore, a Mendelian randomization (MR) study was conducted to overcome these confounding factors and investigate the causal relationship between sarcopenia and KOA.

The present work focused on assessing the causality between KOA and sarcopenia, so as to provide new strategies to prevent and treat these two conditions in clinic.

We registered the title with PROSPERO (ID: CRD42023421096). The two-sample bidirectional MR analysis was conducted in two steps, with sarcopenia being the exposure whereas KOA being the outcome in the first step, and vice versa in the second step. Genome-wide association studies (GWAS) data on low hand-grip strength (n=256,523), walking pace (n=459,915), appendicular lean mass (ALM, n=450,243), and KOA (n=403,124) were obtained from the UK Biobank. Methods such as the inverse variance weighted (IVW) and weighted median were utilized for assessing the causality of KOA with sarcopenia, and sensitivity analyses were also conducted.

In the main MR analysis using the IVW method, evidence suggested that low hand-grip strength, walking pace, and ALM had adverse effects on KOA (p-value 0.0001, odds ratio (OR) 1.4569, 95% confidence interval (CI) 1.2007-1.7677 for low hand-grip strength; p-value 0.0003, OR 1.1500, 95% CI 1.050-1.183 for ALM; p-value 5.29E-19, OR 0.0932, 95% CI 0.0553-0.1572 for walking pace). However, there was no causality of KOA with sarcopenia in the opposite direction.

Our study suggests an obvious unidirectional causality of KOA with sarcopenia, and supports the notion that patients with sarcopenia are more susceptible to the development of KOA.

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).

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).

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).

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.

The main purpose of this study was to review the evidence about the effectiveness of exercise in patients with overweight or obesity suffering from knee osteoarthritis.

Randomized clinical trials (RCTs) published between January 2002 and May 2022 were included.

A total of 64 articles were identified, of which six met the criteria for meta-analysis. The pain scale score was higher in the control group (mean difference 0.95; confidence interval 0.42-1.47; p < 0.001; I2 = 44%). The physical function scale (lower scores indicate lower levels of symptoms or physical disability) presented a higher score in the control group (mean difference 3.74; confidence interval 0.85-6.53; p < 0.05; I2 = 56%). Moreover, the intervention group achieved a greater distance (meters) walking in a 6 min interval (mean difference 38.18; confidence interval 20.01-56.35; p < 0.001; I2 = 0%).

Exercise interventions seem effective in improving quality of life in people with overweight or obesity suffering from knee osteoarthritis, reducing pain and improving physical function.

The aims of this study were to compare the capacity of the knee and hip muscles between individuals with and without isolated patellofemoral osteoarthritis (PFOA) and to evaluate the impact of PFOA on pain, stiffness, and physical function.

This cross-sectional study evaluated muscle capacity of the hip and knee using an isokinetic dynamometer. The isokinetic variables used in the statistical analysis were peak torque, total work, and average power. Pain, stiffness, and physical function were assessed using questionnaires.

A total of 26 individuals participated in the study (13 with PFOA and 13 controls). The PFOA group exhibited lower peak torque, total work, and average power for knee extension and flexion in the concentric mode (p ⩽ 0.01) as well as lower peak torque and total work for knee extension (p ⩽ 0.005) and lower total work for knee flexion (p = 0.05) in the eccentric mode. The PFOA group exhibited lower peak torque of the extensor, abductor, adductor, and internal rotator muscles of the hip (p ⩽ 0.05), less total work of the abductor and adductor muscles (p ⩽ 0.04), and lower average power of eccentric adduction of the hip (p = 0.01) compared with the healthy controls. Compared with the control group, the PFOA group had a higher level of pain, stiffness, and compromised physical functioning self-reported (p ⩽ 0.005).

Participants with PFOA exhibited impairments regarding muscle capacity of the hip and knee, higher level of pain and stiffness as well as compromised physical functioning in comparison with healthy controls.

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.

The loss of strength, power, and muscle mass caused by the progressive deterioration from aging is known as "sarcopenia [...].

Menopausal women are susceptible to osteoarthritis(OA) and memory impairment. We hypothesised that Alzheimer's-like disease(AD) exacerbates OA and that intermittent fasting(IMF) with a high-protein(H-P) diet would enhance memory function and relieve OA symptoms in oestrogen-deficient animals induced AD and OA. The action mechanism was also explored. Ovariectomised Sprague-Dawley rats were fed high-fat(H-F) or H-P diets for 2 weeks, and then they had a hippocampal infusion of β-amyloid(25-35) for 4 weeks to induce AD and an injection of monoidoacetate(MIA) into the articular cartilage to induce OA. Non-AD groups had non-AD symptoms by hippocampal amyloid-β(35-25) infusion. IMF suppressed memory impairment in AD rats, especially those fed H-P diets. Compared with non-AD, AD exacerbated OA symptoms, including swelling, limping, slowed treadmill running speed, and uneven weight distribution in the left leg. The exacerbations were linked to increased inflammation and pain, but IMF and H-P lessened the exacerbation. Lean body mass(LBM) decreased with AD, but H-P protected against LBM loss. Histological examination of the knee joint revealed the degree of the cellular invasion into the middle zone, and the changes in the tidemark plateau were greatest in the AD-AL with H-F, while non-AD-IMF improved the cellular invasion to as much as non-AD-AL. H-P reduced the infiltration into the middle zone of the knee and promoted collagen production. In conclusion, AD exacerbated the articular cartilage deterioration and memory impairment, and IMF with H-P alleviated the memory impairment and osteoarthritic symptoms by decreasing hippocampal amyloid-β deposition and proinflammatory cytokine expressions and by increasing LBM.