Association between body composition and osteoarthritis: A systematic review and meta‐analysis

Metabolic Syndrome and Morbid Obesity are Not Risk Factors for Revision Surgery in Patients Undergoing Hip and Knee Arthroplasty

BACKGROUND

The effect of metabolic syndrome (MetS) on the risk of revision after hip and knee arthroplasty is debated. The aim of our study was to investigate the risk of short-term (minimum 2.7 years) revision due to periprosthetic joint infection (PJI) after hip and knee arthroplasty. Secondly, we aimed to investigate the risk of revision due to any cause and mortality.

METHODS

During May 2017 to November 2019, a cohort of 2,901 patients undergoing a total of 3,024 hip and knee arthroplasties was established. In the cohort, 62.1% met the criteria for MetS. Data from national registries and a local database were used to determine the presence of MetS and revision surgeries, with a follow-up of at least two years and eight months. Cox regression was applied to the present hazard ratio (HR), associated 95% confidence intervals, and P values. Survival analyses were presented in a Kaplan-Meier plot.

RESULTS

The risk of PJI (HR 1.6 (0.5 to 4.9), P = .380), any revision (HR 0.8 (0.4 to 1.3), P = .295), and death (HR 1.3 (0.8 to 2.1), P = .282) was not increased in patients suffering from MetS compared with patients who did not have MetS. There was no PJI in patients not having MetS and receiving a knee arthroplasty. The risk of death was increased in the MetS group receiving a knee arthroplasty (HR 2.7 (1.3 to 5.9), P = .010), but not different from the MetS group receiving a hip arthroplasty. There was no elevated risk of PJI when analyzing morbid obesity (body mass index over 40), men, or diabetes as the exposures.

CONCLUSIONS

Patients suffering from MetS do not have an increased risk of revision caused by PJI. In general, performing hip and knee arthroplasty in patients suffering from MetS is without increased risk of revision surgery.

Causal relationship between sarcopenia with osteoarthritis and the mediating role of obesity: a univariate, multivariate, two-step Mendelian randomization study

BACKGROUND

Recent genetic evidence supports a causal role for sarcopenia in osteoarthritis, which may be mediated by the occurrence of obesity or changes in circulating inflammatory protein levels. Here, we leveraged publicly available genome-wide association study data to investigate the intrinsic causal relationship between sarcopenia, obesity, circulating inflammatory protein levels, and osteoarthritis.

METHODS

In this study, we used Mendelian randomization analyses to explore the causal relationship between sarcopenia phenotypes (Appendicular lean mass [ALM], Low hand-grip strength [LHG], and usual walking pace [UWP]) and osteoarthritis (Knee osteoarthritis [KOA], and Hip osteoarthritis [HOA]). Univariable Mendelian randomization (UVMR) analyses were performed using the inverse variance weighted (IVW) method, MR-Egger, weighted median method, simple mode, and weighted mode, with the IVW method being the primary analytical technique. Subsequently, the independent causal effects of sarcopenia phenotype on osteoarthritis were investigated using multivariate Mendelian randomization (MVMR) analysis. To further explore the mechanisms involved, obesity and circulating inflammatory proteins were introduced as the mediator variables, and a two-step Mendelian randomization analysis was used to explore the mediating effects of obesity and circulating inflammatory proteins between ALM and KOA as well as the mediating proportions.

RESULTS

UVMR analysis showed a causal relationship between ALM, LHG, UWP and KOA [(OR = 1.151, 95% CI: 1.087-1.218, P = 1.19 × 10-6, PFDR = 7.14 × 10-6) (OR = 1.215, 95% CI: 1.004-1.470; P = 0.046, PFDR = 0.055) (OR = 0.503, 95% CI: 0.292-0.867; P = 0.013, PFDR = 0.027)], and a causal relationship between ALM, UWP and HOA [(OR = 1.181, 95% CI: 1.103-1.265, P = 2.05 × 10-6, PFDR = 6.15 × 10-6) (OR = 0.438, 95% CI: 0.226-0.849, P = 0.014, PFDR = 0.022)]. In the MVMR analyses adjusting for confounders (body mass index, insomnia, sedentary behavior, and bone density), causal relationships were observed between ALM, LHG, UWP and KOA [(ALM: OR = 1.323, 95%CI: 1.224- 1.431, P = 2.07 × 10-12), (LHG: OR = 1.161, 95%CI: 1.044- 1.292, P = 0.006), (UWP: OR = 0.511, 95%CI: 0.290- 0.899, P = 0.020)], and between ALM and HOA (ALM: OR = 1.245, 95%CI: 1.149- 1.348, P = 7.65 × 10-8). In a two-step MR analysis, obesity was identified to play a potential mediating role in ALM and KOA (proportion mediated: 5.9%).

CONCLUSIONS

The results of this study suggest that decreased appendicular lean mass, grip strength, and walking speed increase the risk of KOA and decreased appendicular lean mass increases the risk of HOA in patients with sarcopenia in a European population. Obesity plays a mediator role in the occurrence of KOA due to appendicular lean body mass reduction.

Optimal timing of hip and knee arthroplasty after bariatric surgery: A systematic review

Background

Obesity is a risk factor for the development of osteoarthritis and contributes to the increasing demand for total joint arthroplasty (TJA). Because a lower preoperative weight decreases the risk of complications after TJA, and because bariatric surgery (BS) can reduce weight and comorbidity burden, orthopedic surgeons often recommend BS prior to TJA in patients with obesity. However, the optimal timing of TJA after BS in terms of complications, revisions and dislocations is unknown.

Methods

PubMed, Embase and Cochrane CENTRAL databases were systematically searched for any type of study reporting rates of complications, revisions and dislocations in patients who had TJA after BS. The included studies' quality was assessed using the Newcastle-Ottawa Scale.

Results

Out of the 16 studies eligible for review, eight registry-based retrospective studies of high to moderate quality compared different time periods between BS and TJA and overall their results suggest little differences in complication rates. The remaining eight retrospective studies evaluated only one time period and had moderate to poor quality. Overall, there were no clear differences in outcomes after TJA for the different time frames between BS and TJA.

Conclusion

The results of this systematic review suggest that there is limited and insufficient high-quality evidence to determine the optimal timing of TJA after BS in terms of the rates of complications, revisions and dislocations. Given this lack of evidence, timing of TJA after BS will have to be decided by weighing the individual patients' risk factors against the expected benefits of TJA.

Causal analysis of body composition measurements in osteoarthritis knee: a two-sample mendelian randomization study

BACKGROUND

To analyse the causal associations of different physical measures with osteoarthritis knee (KOA).

METHODS

Exposure factors (weight, body mass index (BMI), body fat percentage, waist circumference, hip circumference, waist-hip ratio (WHR), and basal metabolic rate (BMR)), and outcome factor KOA were analyzed by inverse-variance weighted (IVW) method, along with heterogeneity test, sensitivity and pleiotropy analyses. Meta-analysis was used to combine the effect values of IVW methods in different data sources.

RESULTS

Weight, BMI, body fat percentage, waist circumference, hip circumference and BMR analyses showed causal association with increased KOA risk, while WHR analysis indicated a reduction of the incidence of KOA. P-value for all the results was less than 0.05 and F-value large than 20. All results were negative for heterogeneity tests and sensitivity analyses, and there was pleiotropy in weight and BMR. Meta-analysis results showed that the results of Odds Ratios (95% Confidence Intervals) for Weight (1.43(1.35-1.51)), BMI (1.40(1.10-1.78)), body fat percentage (1.56(1.44-1.68)), waist circumference (1.40(1.10-1.78)), hip circumference (1.37(1.30-1.44)), WHR (0.86(0.71-1.04)) and BMR (1.36(1.27-1.46) were consistent with the ones by Mendelian randomization analyses.

CONCLUSIONS

Body fat percentage may be a better indicator of KOA than BMI. In addition, weight and BMR may have a causal effect in KOA, but WHR does not have a causal relationship. BMI, body fat percentage, waist circumference, and hip circumference has a causal effect on KOA.

[Impact of surgical treatment of morbid obesity on joint diseases]

The prevalence of obesity in the modern world is increasing. Obesity is an independent risk factor for some rheumatic diseases and also worsens their course. The presence of chronic joint disease can make it difficult for obesity to reduce activity, creating a vicious circle where joint pain makes exercise difficult and being overweight exacerbates joint pain. At the same time, there is a conditionally radical method of treating obesity - bariatric surgery (BS), which is currently used when conservative methods are ineffective. The purpose of this review is to analyze the data presented in the world literature on the impact of BS on the course of the most common rheumatic diseases. The available data show the possibility of a positive effect of BS not only on weight loss, but also on the course of a number of rheumatic diseases.

Effects of different obesogenic diets on joint integrity, inflammation and intermediate monocyte levels in a rat groove model of osteoarthritis

Introduction: Obesogenic diets aggravate osteoarthritis (OA) by inducing low-grade systemic inflammation, and diet composition may affect OA severity. Here, we investigated the effect of diet on joint damage and inflammation in an OA rat model. Methods: Wistar-Han rats (n = 24) were fed a chow, a high-fat (HF) diet, or a high-fat/high-sucrose (HFS) for 24 weeks. OA was induced unilaterally 12 weeks after the diet onset by groove surgery, and compared to sham surgery or no surgical intervention (contralateral limb). Knee OA severity was determined by OARSI histopathology scoring system. At several timepoints monocyte populations were measured using flow cytometry, and joint macrophage response was determined via CD68 immunohistochemistry staining. Results: Groove surgery combined with HF or HFS diet resulted in higher OARSI scores, and both HF and HFS diet showed increased circulating intermediate monocytes compared to chow fed rats. Additionally, in the HFS group, minimal damage by sham surgery resulted in an increased OARSI score. HFS diet resulted in the largest metabolic dysregulation, synovial inflammation and increased CD68 staining in tibia epiphysis bone marrow. Conclusion: Obesogenic diets resulted in aggravated OA development, even with very minimal joint damage when combined with the sucrose/fat-rich diet. We hypothesize that diet-induced low-grade inflammation primes monocytes and macrophages in the blood, bone marrow, and synovium, resulting in joint damage when triggered by groove OA inducing surgery. When the metabolic dysregulation is larger, as observed here for the HFS diet, the surgical trigger required to induce joint damage may be smaller, or even redundant.

Macrophage-Driven Inflammation in Metabolic Osteoarthritis: Implications for Biomarker and Therapy Development

Osteoarthritis (OA) is a common and debilitating joint disorder that leads to progressive joint breakdown and loss of articular cartilage. Accompanied by a state of low-grade inflammation, its etiology extends beyond that of a wear-and-tear disease, and the immune system might have a role in its initiation and progression. Obesity, which is directly associated with an increased incidence of OA, alters adipokine release, increases pro-inflammatory macrophage activity, and affects joint immune regulation. Studying inflammatory macrophage expression and strategies to inhibit inflammatory macrophage phenotype polarization might provide insights into disease pathogenesis and therapeutic applications. In pre-clinical studies, the detection of OA in its initial stages was shown to be possible using imaging techniques such as SPECT-CT, and advances are made to detect OA through blood-based biomarker analysis. In this review, obesity-induced osteoarthritis and its mechanisms in inducing joint degeneration are summarized, along with an analysis of the current developments in patient imaging and biomarker use for diagnostic and therapeutic strategies.

Sustained release resolvin D1 liposomes are effective in the treatment of osteoarthritis in obese mice

Osteoarthritis (OA) is the most common joint disorder and currently affects >500 million patients worldwide, with ~60% of them also suffering from obesity. There is no drug approved for human use that changes the course of OA progression. OA is one of the most common comorbidities of obesity, and obesity-related OA (ObOA) is a serious health concern because it shows heightened severity of tissue damage and also predominantly affects the working population. Unresolved inflammation is a major driver of ObOA, thus, resolving disease-associated inflammation is a viable strategy to treat ObOA. Resolvins are highly potent molecules that play a role in the resolution of inflammation and promote tissue healing. However, small molecules (like Resolvin D1; RvD1) have to be administered frequently or prior to injury because they lose their in vivo activity rapidly either by lymphatic clearance, or oxidation-mediated deactivation. In this study, we have encapsulated RvD1 in liposomes and established its efficacy in the mouse model of ObOA at much lower dosages than freely administered RvD1. Liposomal RvD1 (lipo-RvD1) acted as a source of the RvD1 molecules for ~11 days in vitro in synovial fluid derived from patients. When administered prophylactically or therapeutically, lipo-RvD1 suppressed cartilage damage in male C57BL/6 mice compared to untreated and free RvD1 treatments. This efficacy was achieved by increasing the proportion of the proresolution M2 macrophages over proinflammatory M1 macrophages in the synovial membrane. These results show the potential of lipo-RvD1 as an anti-OA agent.

Obesity, Bariatric Surgery, and Hip/Knee Arthroplasty Outcomes

Obesity is an independent risk factor for osteoarthritis due to mechanical and inflammatory factors. The gold-standard treatment of end-stage knee and hip osteoarthritis is total joint arthroplasty (TJA). Weight loss decreases progression of osteoarthritis and complications following TJA in patients with obesity. Bariatric surgery allows significant, sustained weight loss and comorbidity resolution in patients with morbid obesity. Existing data describing bariatric surgery on TJA outcomes are limited but suggest a benefit to bariatric surgery prior to TJA. Further studies are needed to determine optimal risk stratification, bariatric procedure selection, and timing of bariatric surgery relative to TJA.

Joint-adjacent Adipose Tissue by MRI is Associated With Prevalence and Progression of Knee Degenerative Changes: Data from the Osteoarthritis Initiative

BACKGROUND

Adipose tissue has recently gained interest as an independent imaging biomarker for osteoarthritis.

PURPOSE

To explore 1) cross-sectional associations between local subcutaneous fat (SCF) thickness at the knee and the extent of degenerative changes in overweight and obese individuals and 2) associations between local fat distribution and progression of osteoarthritis over 4 years.

STUDY TYPE

Retrospective cohort study.

POPULATION

338 obese and overweight participants from the Osteoarthritis Initiative cohort without radiographic evidence of osteoarthritis.

FIELD STRENGTH

3T: 3D-FLASH-WE; 3D-DESS-WE; T1w-SE; MSME.

ASSESSMENT

Baseline SCF thickness was measured in standardized locations medial, lateral and anterior to the knee and the average joint-adjacent SCF (ajSCF) was calculated. Right thigh SCF cross-sectional area was assessed. Quantitative cartilage T₂ relaxation times and semi-quantitative whole organ MRI scores (WORMS) were obtained at baseline and 4-year follow-up. WORMS_sum was calculated as sum of cartilage, bone marrow edema, subchondral cyst, and meniscal scores.

STATISTICAL TESTS

Associations of SCF measures with baseline, and 4-year change in T₂ and WORMS were analyzed using regression models. SCF measurements were standardized using the equation Value Participant - Mean Cohort Standard deviation . Analyses were adjusted for age, sex, physical activity, and BMI.

RESULTS

Cross-sectionally, significant associations between lateral SCF, lateral compartment WORMS and T₂ were found ( Δ WORMS sum 1 SD change in lateral SCF , [95% CI]: 0.53, [0.12-0.95], P < 0.05; ΔT₂ : 0.50, [0.02-0.98], P < 0.05). Moreover, greater lateral SCF was associated with faster progression of lateral WORMS_sum gradings (OR = 1.50, [1.05-2.15], P < 0.05). No significant positive associations were found for thigh SCF and WORMS_sum (P = 0.44) or T₂ measurements (medial: P = 0.15, lateral: 0.39, patellar: P = 0.75).

DATA CONCLUSION

Joint-adjacent SCF thickness was associated with imaging parameters of knee osteoarthritis, both cross-sectionally and longitudinally, while thigh SCF was not, suggesting a spatial association of SCF and knee osteoarthritis. Based on these findings, joint-adjacent SCF may play a role in the development and progression of knee osteoarthritis.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY: Stage 5.