Association between smoking and risk of knee osteoarthritis: a systematic review and meta-analysis

Causal relationship between periodontal disease-related phenotype and knee osteoarthritis: A two-sample mendelian randomization analysis

OBJECTIVE

This study aimed to explore the bidirectional causal relationship between periodontal disease-related phenotype (PDRP) and knee osteoarthritis (KOA) in a European population using a two-sample Mendelian Randomization (MR) approach.

METHODS

We leveraged publicly available GWAS summary statistics for PDRP (n = 975) and KOA (n = 403,124), assessing their roles as both exposures and outcomes. Our comprehensive MR analysis employed various methods, including inverse variance weighting (IVW), weighted median, Egger regression, simple mode, and weighted mode, to enhance the robustness of our findings. To ensure the reliability of our instrumental variables, we implemented a rigorous screening process based on p-values and F-values, utilized Phenoscanner to investigate potential confounders, and conducted sensitivity analyses.

RESULTS

Our analysis identified five SNPs associated with PDRP and three SNPs with KOA, all surpassing the genome-wide significance threshold, as instrumental variables. The IVW method demonstrated a significant causal relationship from PDRP to KOA (beta = 0.013, SE = 0.007, P = 0.035), without evidence of directional pleiotropy (MR-Egger regression intercept = 0.021, P = 0.706). No support was found for reverse causality from KOA to PDRP, as further MR analyses yielded non-significant P-values. Additionally, funnel plots and Cochran's Q test detected no significant heterogeneity or directional pleiotropy, confirming the robustness of our results. In multivariate analysis, when considering smoking, alcohol consumption, BMI collectively no direct causal relationship between KOA and PDRP. Conversely, smoking and higher BMI were independently associated with an increased risk of KOA.

CONCLUSION

In conclusion, our analysis revealed no direct causal relationship from KOA to PDRP. However, a causal relationship from PDRP to KOA was observed. Notably, when adjusting for potential confounders like smoking, alcohol intake, and BMI, both the causal connection from PDRP to KOA and the inverse relationship were not substantiated.

Intra-articular steroids for the treatment of coxarthrosis; a retrospective cohort study comparing three contrast techniques

INTRODUCTION

Intra-articular steroid injections (IAS) are a treatment for coxarthrosis. This study examines the efficacy of three fluoroscopy-guided IAS contrast techniques for coxarthrosis: contrast-assisted (Iohexol), air arthrogram-assisted and blind (contrast/air free) and stratifies efficacy based on multiple patient variables.

MATERIALS AND METHODS

A cohort of 307 hip IAS was retrospectively analysed over a four-year period. The primary outcome was efficacy of IAS between each technique group, defined by duration of symptomatic relief. The secondary outcome was efficacy based on multiple patient variables. Variables included age, BMI, gender, type of osteoarthritis, grade of osteoarthritis, smoking status, co-morbidity index and duration of pre-injection symptoms. Chi-squared, Pearson, One Way ANOVA and F-tests were used for statistical analysis.

RESULTS

Total failure (< 1 week symptomatic relief) was 20% (contrast 20%, air 14%, blind 26%). >3 months of symptomatic relief was experienced by 35%, with the air arthrogram technique containing the largest proportion of IAS achieving > 3months of relief within its own group (contrast 35%, air 38%, blind 28%). Non-smokers experienced a longer duration of symptomatic relief in the air arthrogram group (p = 0.04). Older patients had a longer duration of symptomatic relief with the blind technique (p = < 0.001). There were no significant differences between the three techniques based on the other patient variables.

CONCLUSION

Air arthrogram is an effective method of confirming injection placement in hip IAS for coxarthrosis and the use of a contrast agent (e.g., Iohexol) may not be required. Non-contrast techniques may produce longer duration of symptomatic relief in non-smokers and in older patients.

Circulating Copper Is Associated with Inflammatory Biomarkers in Greek Older Adults with Osteoarthritis

Osteoarthritis (OA) is the most common form of arthritis, that causes a significant decrease in the quality of life of the afflicted and constitutes a great burden for the socioeconomic system. Trace elements and heavy metals are implicated in the pathophysiology of OA, exacerbating inflammatory and oxidative stress responses. The aim of this cross-sectional study was to quantify metals in plasma samples of Greek OA patients and explore their link with disease related parameters, health status or quality of life, as well as epigenetic OA markers. This is the first study on plasma metal levels in Greek knee OA patients. To achieve precision in plasma metal and miRNA measurements, high-quality samples were selected from a subset of 34 participants (NCT04783792). Demographic, quality of life, clinical, biochemical, inflammation, oxidative stress, and anthropometric parameters, as well as microRNA levels were assessed. Significant correlations were found between circulating metals with OA related parameters or with measured microRNAs. Also, significant positive associations between plasma copper (Cu) levels and CRP (p = 0.033) or IL-6 (p = 0.001) occurred when adjusting for age, gender, BMI, physical activity level, smoking, disease severity, total arthroplasty, and dietary intake of the respective metal. Cu's role in OA is bidirectional, and this study confirms the findings that in OA, Cu is positively associated with inflammation. Such relationships between lifestyle, environment and OA enhance our understanding and encourage further study on metals related to OA inflammation.

Systematic replication of smoking disease associations using survey responses and EHR data in the All of Us Research Program

OBJECTIVE

The All of Us Research Program (All of Us) aims to recruit over a million participants to further precision medicine. Essential to the verification of biobanks is a replication of known associations to establish validity. Here, we evaluated how well All of Us data replicated known cigarette smoking associations.

MATERIALS AND METHODS

We defined smoking exposure as follows: (1) an EHR Smoking exposure that used International Classification of Disease codes; (2) participant provided information (PPI) Ever Smoking; and, (3) PPI Current Smoking, both from the lifestyle survey. We performed a phenome-wide association study (PheWAS) for each smoking exposure measurement type. For each, we compared the effect sizes derived from the PheWAS to published meta-analyses that studied cigarette smoking from PubMed. We defined two levels of replication of meta-analyses: (1) nominally replicated: which required agreement of direction of effect size, and (2) fully replicated: which required overlap of confidence intervals.

RESULTS

PheWASes with EHR Smoking, PPI Ever Smoking, and PPI Current Smoking revealed 736, 492, and 639 phenome-wide significant associations, respectively. We identified 165 meta-analyses representing 99 distinct phenotypes that could be matched to EHR phenotypes. At P < .05, 74 were nominally replicated and 55 were fully replicated. At P < 2.68 × 10-5 (Bonferroni threshold), 58 were nominally replicated and 40 were fully replicated.

DISCUSSION

Most phenotypes found in published meta-analyses associated with smoking were nominally replicated in All of Us. Both survey and EHR definitions for smoking produced similar results.

CONCLUSION

This study demonstrated the feasibility of studying common exposures using All of Us data.

The Causal Association between Alcohol, Smoking, Coffee Consumption, and the Risk of Arthritis: A Meta-Analysis of Mendelian Randomization Studies

Objective: To evaluate the genetic causality between alcohol intake, smoking, coffee consumption, and arthritis. Methods: Mendelian randomization (MR) studies with alcohol, smoking, and coffee consumption behaviors as exposures, and osteoarthritis (OA) and rheumatoid arthritis (RA) as outcomes were retrieved from up to July 2023. Two researchers with relevant professional backgrounds independently assessed the quality and extracted data from the included studies. Meanwhile, we applied MR analyses of four lifestyle exposures and five arthritis outcomes (two for OA and three for RA) with gene-wide association study (GWAS) data that were different from the included studies, and the results were also included in the meta-analysis. Statistical analyses were performed using Stata 16.0 and R software version 4.3.1. Results: A total of 84 studies were assessed. Of these, 11 were selected for meta-analysis. As a whole, the included studies were considered to be at a low risk of bias and were of high quality. Results of the meta-analysis showed no significant genetic causality between alcohol intake and arthritis (odds ratio (OR): 1.02 (0.94-1.11)). Smoking and arthritis had a positive genetic causal association (OR: 1.44 (1.27-1.64)) with both OA (1.44 (1.22-1.71)) and RA (1.37 (1.26-1.50)). Coffee consumption and arthritis also had a positive genetic causal association (OR: 1.02 (1.01-1.03)). Results from the subgroup analysis showed a positive genetic causality between coffee consumption and both OA (OR: 1.02 (1.00-1.03)) and RA (OR: 1.56 (1.19-2.05)). Conclusion: There is positive genetic causality between smoking and coffee consumption and arthritis (OA and RA), while there is insufficient evidence for genetic causality between alcohol intake and arthritis.

Cigarette smoking is linked to an increased risk of delirium following arthroplasty in patients suffering from osteoarthritic pain

AIMS

Postoperative delirium (POD) is a common postoperative complication, and the potential relationship between cigarette smoking and POD is still unclear. The current study evaluated the relationship between preoperative smoking status in patients suffering from osteoarthritic pain and POD after total knee arthroplasty (TKA).

METHODS

A total of 254 patients who had undergone unilateral TKA were enrolled between November 2021 and December 2022, with no gender limitation. Preoperatively, patients' visual analog scale (VAS) scores at rest and during movement, hospital anxiety and depression (HAD) scores, pain catastrophizing scale (PCS) scores and smoking status were collected. The primary outcome was the incidence of POD, which was evaluated by the confusion assessment method (CAM).

RESULTS

A total of 188 patients had complete datasets for final analysis. POD was diagnosed in 41 of 188 patients (21.8%) who had complete data for analysis. The incidence of smoking was significantly higher in Group POD than in Group Non-POD (22 of 41 patients [54%] vs. 47 of 147 patients [32%], p < 0.05). The postoperative hospital stays were also longer than those of Group Non-POD (p < 0.001). Multiple logistic regression analysis showed that preoperative smoking (OR: 4.018, 95% CI: 1.158-13.947, p = 0.028) was a risk factor for the occurrence of POD in patients with TKA. The length of hospital stay was correlated with the occurrence of POD.

CONCLUSIONS

Our findings suggest that patients who smoked preoperatively were at increased risk of developing POD following TKA.

Assessment of the relationship between smoking and meniscal injury

Objective

To determine whether being a smoker and the years of smoking correlate with the presence and degree of meniscal injury.

Materials and Methods

Individuals who underwent magnetic resonance imaging of the knee were divided into two groups: smokers and nonsmokers. For each smoker, the total smoking history was calculated by multiplying the daily consumption (packs/day) by the years of smoking, and the result is expressed as pack-years. In the evaluation of meniscal injury, the grade of injury was recorded. The thickness of the subcutaneous adipose tissue, as an indicator of obesity, was measured at the medial knee on axial plane images. The relationships that smoking and obesity had with meniscal injury were analyzed statistically.

Results

A total of 156 individuals were included in the study. The smoker group consisted of 48 individuals (30.8%), and the nonsmoker group consisted of 108 (69.2%). The meniscus was normal in one (2.1%) of the smokers and in 32 (29.6%) of the nonsmokers (p < 0.0001). The median subcutaneous adipose tissue thickness was 23 mm and 24 mm in the smokers and nonsmokers, respectively (p = 0.900). A moderate but statistically significant correlation was observed between packs/day and injury grade, as well as between pack-years and injury grade (r = 0.462, p = 0.001 and r = 0.523, p = 0.001, respectively). Smoking and age significantly increased the risk of meniscal injury, by 31.221 times (p = 0.001) and 1.076 times (p < 0.001), respectively.

Conclusion

Our findings indicate that current smoking and smoking history correlate significantly with meniscal injury grade.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Persistent high prevalence of modifiable cardiovascular risk factors among patients with osteoarthritis in the UK in 1992-2017

OBJECTIVES

To compare the annual and period prevalence of modifiable cardiovascular risk factors (MCVRFs) between populations with and without osteoarthritis (OA) in the UK over 25 years.

METHODS

215 190 patients aged 35 years and over from the UK Clinical Practice Research Datalink GOLD database who were newly diagnosed OA between 1992 and 2017, as well as 1:1 age-matched, sex-matched, practice-matched and index year-matched non-OA individuals, were incorporated. MCVRFs including smoking, hypertension, type 2 diabetes, obesity and dyslipidaemia were defined by Read codes and clinical measurements. The annual and period prevalence and prevalence rate ratios (PRRs) of individual and clustering (≥1, ≥2 and ≥3) MCVRFs were estimated by Poisson regression with multiple imputations for missing values.

RESULTS

The annual prevalence of MCVRFs increased in the population with OA between 1992 and 2017 and was consistently higher in the population with OA compared with the population without OA between 2004 and 2017. Trends towards increased or stable annual PRRs for individuals and clustering of MCVRFs were observed. A 26-year period prevalence of single and clustering MCVRFs was significantly higher in individuals with OA compared with non-OA individuals. Period PRRs were higher in Southern England, women and increased with age for most MCVRFs except for obesity, which has the higher PRR in the youngest age group.

CONCLUSIONS

A consistently higher long-term prevalence of MCVRFs was observed in individuals with OA compared to those without OA. The higher prevalence of obesity in the youngest age group with OA highlights the need for public health strategies. Further research to understand MCVRF management in OA populations is necessary.

Hospital variation in revision rates after primary knee arthroplasty was not explained by patient selection: baseline data from 1452 patients in the Danish prospective multicenter cohort study, SPARK

PURPOSE

Revision rates following primary knee arthroplasty vary by country, region and hospital. The SPARK study was initiated to compare primary surgery across three Danish regions with consistently different revision rates. The present study investigated whether the variations were associated with differences in the primary patient selection.

METHODS

A prospective observational cohort study included patients scheduled Sep 2016 Dec 2017 for primary knee arthroplasty (total, medial/lateral unicompartmental or patellofemoral) at three high-volume hospitals, representing regions with 2-year cumulative revision rates of 1, 2 and 5%, respectively. Hospitals were compared with respects to patient demographics, preoperative patient-reported outcome measures, motivations for surgery, implant selection, radiological osteoarthritis and the regional incidence of primary surgery. Statistical tests (parametric and non-parametric) comprised all three hospitals.

RESULTS

Baseline data was provided by 1452 patients (89% of included patients, 56% of available patients). Patients in Copenhagen (Herlev-Gentofte Hospital, high-revision) were older (68.6 ± 9 years) than those in low-revision hospitals (Aarhus 66.6 ± 10 y. and Aalborg (Farsø) 67.3 ± 9 y., p = 0.002). In Aalborg, patients who had higher Body Mass Index (mean 30.2 kg/m² versus 28.2 (Aarhus) and 28.7 kg/m² (Copenhagen), p < 0.001), were more likely to be male (56% versus 45 and 43%, respectively, p = 0.002), and exhibited fewer anxiety and depression symptoms (EQ-5D-5L) (24% versus 34 and 38%, p = 0.01). The preoperative Oxford Knee Score (23.3 ± 7), UCLA Activity Scale (4.7 ± 2), range of motion (Copenhagen Knee ROM Scale) and patient motivations were comparable across hospitals but varied with implant type. Radiological classification ≥ 2 was observed in 94% (Kellgren-Lawrence) and 67% (Ahlbäck) and was more frequent in Aarhus (low-revision) (p ≤ 0.02), where unicompartmental implants were utilized most (49% versus 14 (Aalborg) and 23% (Copenhagen), p < 0.001). In the Capital Region (Copenhagen), the incidence of surgery was 15-28% higher (p < 0.001).

CONCLUSION

Patient-reported outcome measures prior to primary knee arthroplasty were comparable across hospitals with differing revision rates. While radiographic classifications and surgical incidence indicated higher thresholds for primary surgery in one low-revision hospital, most variations in patient and implant selection were contrary to well-known revision risk factors, suggesting that patient selection differences alone were unlikely to be responsible for the observed variation in revision rates across Danish hospitals.

LEVEL OF EVIDENCE

II, Prospective cohort study.

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.

Association of smoking and osteoarthritis in US (NHANES 1999-2018)

Little is currently known about the effect of smoking on osteoarthritis (OA). This study aimed to investigate the relationship between smoking and OA in the United States (US) general population. Cross-sectional study. Level of evidence, 3. 40,201 eligible participants from the National Health and Nutrition Examination Survey 1999-2018 were included and divided into OA and non-arthritis groups. Participants demographics and characteristics were compared between the two groups. Then the participants were divided into non-smokers, former smokers, and current smokers based on their smoking status, also demographics and characteristics among the three groups were compared. Multivariable logistic regression was used to determine the relationship between smoking and OA. The current and former smoking rate in the OA group (53.0%) was significantly higher than that in the non-arthritis group (42.5%; p < 0.001). Multivariable regression analysis including body mass index (BMI), age, sex, race, education level, hypertension, diabetes, asthma and cardiovascular disease showed that smoking was an association for OA. This large national study highlights a positive association between smoking and OA prevalence in the general US population. It is necessary to further study the relationship between smoking and OA in order to determine the specific mechanism of smoking on OA.

Prevalence of Symptomatic Knee Osteoarthritis in Saudi Arabia and Associated Modifiable and Non-Modifiable Risk Factors: A Population-Based Cross-Sectional Study

OBJECTIVE

This study aimed to determine the prevalence of knee osteoarthritis (OA) in Saudi Arabia and the association between knee OA and modifiable and non-modifiable risk factors.

METHODS

A self-reported, population-based, cross-sectional survey between January 2021 and October 2021 was conducted. A large, population-representative sample (n = 2254) of adult subjects aged 18 years and over from all regions of Saudi Arabia was collected electronically using convenience sampling. The American College of Rheumatology (ACR) clinical criteria were used to diagnose OA of the knee. The knee injury and osteoarthritis outcome score (KOOS) was used to investigate the severity of knee OA. This study focused on modifiable risk factors (body mass index, education, employment status, marital status, smoking status, type of work, previous history of knee injury, and physical activity level) and non-modifiable risk factors (age, gender, family history of OA, and presence of flatfoot).

RESULTS

The overall prevalence of knee OA was 18.9% (n = 425), and women suffered more compared to their male counterparts (20.3% vs. 13.1%, p = 0.001). The logistic regression analysis model showed age (OR: 1.06 [95% CI: 1.05-1.07]; p < 0.01), sex (OR: 2.14 [95% CI: 1.48-3.11]; p < 0.01), previous injury (OR: 3.95 [95% CI: 2.81-5.56]; p < 0.01), and obesity (OR: 1.07 [95% CI: 1.04-1.09]; p < 0.01) to be associated with knee OA.

CONCLUSIONS

A high prevalence of knee OA underlines the need for health promotion and prevention programmes that focus on modifiable risk factors to decrease the burden of the problem and the cost of treatment in Saudi Arabia.

Air pollution exposure and auto-inflammatory and autoimmune diseases of the musculoskeletal system: a review of epidemiologic and mechanistic evidence

Auto-inflammatory and autoimmune diseases of the musculoskeletal system can be perceived as a spectrum of rheumatic diseases, with the joints and connective tissues are eroded severely that progressively develop chronic inflammation and lesion. A wide range of risk factors represented by genetic and environmental factors have been uncovered by population-based surveys and experimental studies. Lately, the exposure to air pollution has been found to be potentially involved in the mechanisms of occurrence or development of such diseases, principally manifest in oxidative stress, local and systemic inflammation, and epigenetic modifications, as well as the mitochondrial dysfunction, which has been reported to participate in the intermediate links. The lungs might serve as a starting area of air pollutants, which would cause oxidative stress-induced bronchial-associated lymphoid tissue (iBALT) to further to influence T, B cells, and the secretion of pro-inflammatory cytokines. The binding of aromatic hydrocarbon receptor (AhR) to the corresponding contaminant ligands tends to regulate the reaction of Th17 and Tregs. Furthermore, air pollution components might spur on immune and inflammatory responses by damaging mitochondria that could interact with and exacerbate oxidative stress and pro-inflammatory cytokines. In this review, we focused on the association between air pollution and typical auto-inflammatory and autoimmune diseases of the musculoskeletal system, mainly including osteoarthritis (OA), rheumatoid arthritis (RA), spondyloarthritis (SpA) and juvenile idiopathic arthritis (JIA), and aim to collate the mechanisms involved and the potential channels. A complete summary and in-depth understanding of the autoimmune and inflammatory effects of air pollution exposure should hopefully contribute new perspectives on how to formulate better public health policies to alleviate the adverse health effects of air pollutants.

The Effect of Smoking on the Outcome of Matrix-Based Autologous Chondrocyte Implantation: Data from the German Cartilage Registry

Smoking is known to have various deleterious effects on health. However, it is not clear whether smoking negatively affects the postoperative outcome following matrix-based autologous cartilage implantation (MACI) in the knee. The purpose of this study was to evaluate the effect of smoking on the outcome of MACI in the knee. A total of 281 patients receiving MACI in the knee between 2015 and 2018 were registered in the German Cartilage Database. The cohort was divided into ex-smokers, smokers, and nonsmokers. Data regarding the Knee Injury and Osteoarthritis Outcome Score (KOOS), the numeric rating scale (NRS) for pain, and satisfaction with the outcome were analyzed and compared. Follow-ups were performed at 6, 12, and 24 months after surgery. Of the 281 patients, 225 (80.1%) were nonsmokers, 43 (15.3%) were smokers, and 13 (4.6%) were ex-smokers. The three groups were comparable with respect to age, sex, body mass index (BMI), height, defect size, the need for additional reconstruction of the subchondral bone defect, number of previous knee surgeries, and defect location. However, nonsmokers had a significantly lower weight as compared with smokers. Besides a significantly lower preoperative NRS of nonsmokers as compared with smokers, there were no significant differences between the three groups with respect to KOOS, NRS, and satisfaction at 6, 12, and 24 months of follow-ups. The present study of data retrieved from the German Cartilage Registry suggests that the smoking status does not influence the outcome of MACI in the knee.

Risk of symptomatic osteoarthritis associated with exposure to ergonomic factors at work in a nationwide Italian survey

OBJECTIVE

The risk of developing osteoarthritis (OA) has been reported to increase with exposure to various ergonomic factors at work, although this finding is still debated in the literature. Aim of this study was to assess the association between prevalence of symptomatic OA and exposure to workplace ergonomic factors assigned through a job-exposures matrix (JEM).

METHODS

The study population was composed of 24,604 persons of 40-69 years who participated in the National Health Survey 2013 and were employed at that occasion. Exposure to ergonomic factors was assigned to the study population through a JEM constructed from the Italian O*NET database, consisting of 17 physical factors, which were summed and averaged by job title (796 jobs) to obtain a combined exposure index. The outcome was self-reported OA characterized by moderate or severe limitations in daily activities. The relationship between OA prevalence and the combined exposure index in quartiles was examined using robust Poisson regression models adjusted for socio-demographics and potential confounders.

RESULTS

In the analysis adjusted for age and gender, the risk of OA was increased by approximately 20-30% in the second and third quartiles, and by 80% in the highest exposure quartile, compared to the least exposed, with a risk attenuation by approximately 15-20% controlling for other significant covariates.

CONCLUSION

Our results support a causal role of exposure to physical factors at work in the development of OA. As OA is associated with a great burden of disability, any effort should be made to reduce workers' exposure to ergonomic factors.

Predictors of Lumbar Spine Degeneration and Low Back Pain in the Community: The Johnston County Osteoarthritis Project

OBJECTIVE

To determine the incidence and worsening of lumbar spine structure and low back pain (LBP) and whether they are predicted by demographic characteristics or clinical characteristics or appendicular joint osteoarthritis (OA).

METHODS

Paired baseline (2003-2004) and follow-up (2006-2010) lumbar spine radiographs from the Johnston County Osteoarthritis Project were graded for osteophytes (OST), disc space narrowing (DSN), spondylolisthesis, and presence of facet joint OA (FOA). Spine OA was defined as at least mild OST and mild DSN at the same level for any level of the lumbar spine. LBP, comorbidities, and back injury were self-reported. Weibull models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) of spine phenotypes accounting for potential predictors including demographic characteristics, clinical characteristics, comorbidities, obesity, and appendicular OA.

RESULTS

Obesity was a consistent and strong predictor of incidence of DSN (HR 1.80 [95% CI 1.09-2.98]), spine OA (HR 1.56 [95% CI 1.01-2.41]), FOA (HR 4.99 [95% CI 1.46-17.10]), spondylolisthesis (HR 1.87 [95% CI 1.02-3.43]), and LBP (HR 1.75 [95% CI 1.19-2.56]), and worsening of DSN (HR 1.51 [95% CI 1.09-2.09]) and LBP (HR 1.51 [95% CI 1.12-2.06]). Knee OA was a predictor of incident FOA (HR 4.18 [95% CI 1.44-12.2]). Spine OA (HR 1.80 [95% CI 1.24-2.63]) and OST (HR 1.85 [95% CI 1.02-3.36]) were predictors of incidence of LBP. Hip OA (HR 1.39 [95% CI 1.04-1.85]) and OST (HR 1.58 [95% CI 1.00-2.49]) were predictors of LBP worsening.

CONCLUSION

Among the multiple predictors of spine phenotypes, obesity was a common predictor for both incidence and worsening of lumbar spine degeneration and LBP.

Association Between History of Gestational Diabetes Mellitus and the Risk of Arthritis in Women

Objective

The association between gestational diabetes mellitus (GDM) and the risk of arthritis has not been reported. GDM increases the risk of long-term complications including diabetes and metabolic syndrome that are positively associated with the risk of arthritis. This study aimed to explore the association between GDM and the risk of arthritis.

Methods

Women (age ≥ 20 years) who had delivered at least one live birth were included from the 2007 to 2018 National Health and Nutrition Examination Survey cohort (N = 11,997). Patients who had a history of GDM and arthritis were identified by in-home interview. Subgroup analyses were conducted by arthritis types and status of obesity, current diabetes, metabolic syndrome, smoking, alcohol drinking, and physical activity.

Results

GDM was associated with increased odds of arthritis [multivariable-adjusted odds ratio (95% confidence interval): 1.31 (1.06–1.62)], and the result was similar in sensitivity analysis with further adjustment for metabolic syndrome [1.30 (1.05–1.60)]. In subgroup analyses, GDM was associated with increased odds of osteoarthritis [1.47 (1.05–2.06)], while no association was observed with rheumatoid arthritis [1.04 (0.69–1.57)] and other types [1.26 (0.94–1.68)]. GDM was associated with increased odds of arthritis in women without metabolic syndrome [1.34 (1.00–1.78)] and diabetes [1.35 (1.03–1.76)], in obese individuals [1.64 (1.24–2.16)], current/former smokers [1.43 (1.05–1.95)], and current drinkers [1.76 (1.00–3.14)], and in individuals engaging in higher levels of physical activity [1.53 (1.06–2.20)].

Conclusions

GDM was associated with increased odds of arthritis, and the association was independent of type 2 diabetes and metabolic syndrome.

Smoking Cessation Rates among Patients with Rheumatoid Arthritis and Osteoarthritis Following the 'Gold Standard Programme' (GSP): A Prospective Analysis from the Danish Smoking Cessation Database

(1) Background: Smoking cessation may be very difficult, even if smoking aggravates the prognosis of a disease, which has been shown to be the case for persons with rheumatoid arthritis (RA). In contrast, an association in patients with osteoarthritis (OA) is still disputed. The primary objective was to compare smokers diagnosed with RA and OA to controls, regarding smoking cessation rates after following the intensive 'Gold Standard programme' (GSP). Secondary objectives included the identification of significant prognostic factors for successful quitting. (2) Methods: In total, 24,652 patients were included in this prospective cohort study, after attending the national GSP for smoking cessation intervention 2006-2016, as registered in the Danish Smoking Cessation Database. Data were linked to the National Patient Register. Hereof, 227 patients (1%) were diagnosed with seropositive RA and 2899 (12%) with OA. Primary outcome was continuous abstinence six months after the planned quitting date. (3) Results: In total, 16,969 (69%) of the patients participated in the follow-up interviews. The adjusted odds ratios for successful quitting were similar to the control group for both RA (1.28, 95% CI: 0.90-1.80) and OA patients (0.92, 0.82-1.03). The outermost, strongest positive factor for successful quitting was compliance, defined as attending ≥75% of the meetings. To a lesser degree, attending an individual intervention was a positive predictor, while being heavy smokers, disadvantaged smokers, women, living with a smoker, and if GSP was recommended by health professionals were negative predictors. (4) Conclusions: The odds ratios for quitting were similar to controls for both RA and OR patients. Additional research is needed to determine effective actions towards increased attendance at the programmes.

Impact of Cadmium Mediated by Tobacco Use in Musculoskeletal Diseases

Tobacco use has a negative impact on health due to its relationship with the development of high-mortality diseases, such as pulmonary cancer. However, the effect of cadmium (Cd), present in tobacco smoke, on the development of joint diseases has been scarcely studied. The objective of this review is to discuss the evidence regarding the mechanisms by which Cd exposure, through tobacco smoke, may lead to the development of osteoarthritis (OA), osteoporosis (OP), and rheumatoid arthritis (RA). There's evidence suggesting a string association between moderate to severe OA development and tobacco use, and that a higher blood concentration of Cd can trigger oxidative stress (OS) and inflammation, favoring cartilage loss. At the bone level, the Cd that is inhaled through tobacco smoke affects bone mineral density, resulting in OP mediated by a decrease in the antioxidant enzymes, which favors the bone resorption process. In RA, tobacco use promotes the citrullination process through Cd exposure and increases OS and inflammation. Understanding how tobacco use can increase the damage at the articular level mediated by a toxic metal, i.e., Cd, is important. Finally, we propose prevention, control, and treatment strategies for frequently disabling diseases, such as OA, OP, and RA to reduce its prevalence in the population.

Are There Racial Disparities in Knee Symptoms and Articular Cartilage Damage in Patients Presenting for Arthroscopic Partial Meniscectomy?

The purpose of the present study was to examine whether Black patients presenting for arthroscopic partial meniscectomy (APM) have worse baseline knee pain, worse knee function, and greater articular cartilage damage than White patients.

Association between osteoarthritis and the incidence of Parkinson's disease in the United Kingdom

Background

Little is known on the potential relationship between osteoarthritis and Parkinson’s disease.

Objective

Therefore, the objective of this retrospective cohort study was to analyze the association between osteoarthritis and the incidence of Parkinson’s disease in patients followed up for up to 10 years in general practices in the United Kingdom.

Methods

This study included patients diagnosed for the first time with osteoarthritis in one of 256 general practices in the United Kingdom between 2000 and 2016 (index date). Patients without osteoarthritis were matched (1:1) to those with osteoarthritis using propensity scores based on sex, age and index year. In individuals without osteoarthritis, index date corresponded to a randomly selected visit date. The outcome of this study was the 10-year cumulative incidence of Parkinson’s disease in patients with and without osteoarthritis. Cox regression analyses were adjusted for common comorbidities.

Results

This study included 260,224 patients (62.0% women; mean [SD] age 66.4 [12.7] years). The 10-year cumulative incidence of Parkinson’s disease was 1.2% in patients with osteoarthritis and 0.6% in their counterparts without osteoarthritis (log-rank p-value < 0.001). The adjusted Cox regression model further showed a positive and significant association between osteoarthritis and the incidence of Parkinson’s disease (HR = 1.82, 95% CI: 1.63–2.02). Similar results were obtained in all sex and age subgroups.

Conclusions

In this retrospective cohort study conducted in the United Kingdom, there was a positive association between osteoarthritis and the incidence of Parkinson’s disease. More research is warranted to confirm or refute these findings in other settings and countries.

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

OBJECTIVES

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

DESIGN

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

RESULTS

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

CONCLUSIONS

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

Smoking and alcohol use in unemployed populations: a systematic review and meta-analysis

Unemployment is an economic and social phenomenon that has economic, social, personal, and health consequences. This study aimed to investigate the relationship between unemployment and alcohol use and smoking as a systematic review and meta-analysis.

The two databases PubMed and Scopus were selected for the search and using a set of keywords, these two sources of scientific information were searched from 2004 to June 2021 and 1996 until June 2021, respectively. To meta-analyze the relationship between unemployment and smoking and alcohol use, odds ratio and confidence interval were calculated for this relationship. The meta-analysis was performed based on a random-effects. Subgroups were also performed for men and women. Heterogeneity in studies as well as publication bias were also examined.

A total of 52 cross-sectional and cohort studies were included in the meta-analysis. In the relationship between unemployment and alcohol use, the odds ratio was 1.25 and the confidence interval was between 1.12 and 1.41. In the relationship between unemployment and smoking, the odds ratio was 1.43 and the confidence interval was between 1.13 and 1.81.

According to the results, it can be said that unemployment increases the likelihood of alcohol use and smoking. Therefore, policymakers must pay more attention to the health consequences of economic problems, especially unemployment.

Prevalence of symptomatic osteoarthritis in Spain: EPISER2016 study

INTRODUCTION

The Spanish Society of Rheumatology carried out the EPISER2000 study in 2000 to determine the prevalence of osteoarthritis and other rheumatic diseases in the Spanish population. Recent sociodemographic changes and lifestyle habits in Spain justified updating the epidemiological data on osteoarthritis and other rheumatic diseases (EPISER2016-study).

OBJECTIVE

To estimate the prevalence of symptomatic osteoarthritis of the cervical spine, lumbar spine, hip, knee and hand in the adult population in Spain.

MATERIAL AND METHODS

Cross-sectional population-based study. A multistage and stratified random cluster sampling was carried out. The participants were contacted by telephone to complete an osteoarthritis screening questionnaire. A rheumatologist confirmed or discarded the diagnosis. The ACR-clinical-criteria were used to diagnose hand-osteoarthritis and the ACR-clinical-radiological criteria to diagnose knee- and hip-osteoarthritis. To estimate the prevalence and its 95% confidence interval, weights were calculated according to the probability of selection in each of the sampling stages.

RESULTS

The prevalence of osteoarthritis in Spain in one or more of the locations studied was 29.35%. The prevalence of cervical-osteoarthritis was 10.10% and of lumbar-osteoarthritis 15.52%. Both are more frequent in women and at older ages, as well as in people with low levels of education and obesity. The prevalence of hip-osteoarthritis was 5.13%, that of knee-osteoarthritis 13.83%, these are associated with female sex, overweight and obesity. The prevalence of hand osteoarthritis was 7.73%. It is more frequent in women, who are obese, with a low educational level and who are older.

CONCLUSION

The EPISER2016 study is the first to analyse the prevalence of symptomatic osteoarthritis in 5 locations (cervical, lumbar, knee, hip and hands) in Spain. Lumbar spine osteoarthritis is the most prevalent.

Pain Pharmacotherapy in a Large Cohort of Patients with Osteoarthritis: A Real-World Data Analysis

INTRODUCTION

There is limited evidence on the consumption of analgesics in real-world large cohorts of patients with osteoarthritis (OA), especially in those with comorbidities. We aimed to characterize the use of pharmacological analgesic treatments, evaluate standardized comorbidity rates, and assess treatment trends. Our hypotheses were: (1) OA patients generally consume low and inconsistent pharmacological analgesic treatments; (2) analgesic treatment is often non-congruent with comorbidity-related safety concerns.

METHODS

The study was carried out at the second largest health maintenance organization in Israel. Members aged 18 years or above who were diagnosed with OA before December 31, 2018, were included. Information was obtained from the members' electronic medical record (EMR) including data on dispensed prescriptions, which were used to estimate analgesic consumption.

RESULTS

A total of 180,126 OA patients were included in our analyses; analgesics were dispensed to 64.2% of the patients, with oral NSAIDs and opioids dispensed to 34.1 and 22.9% of the OA population, respectively. Analgesic use increased with time lapsed from OA diagnosis (p < 0.001), up to a median of 59 days covered (IQR, 20-175) after 21 years. Rates of most comorbidities in the OA population were higher compared to the MHS general population. Patients with comorbidities used more NSAIDs and opioids compared to those without them.

CONCLUSIONS

Most OA patients use analgesics, usually oral NSAIDs. Analgesic use remains relatively low throughout the years, indicating that many OA patients are not being treated pharmacologically for pain on a regular basis. Despite having higher rates of several comorbidities compared to MHS general population, many OA patients are still treated with analgesics that can be associated with a worsening in comorbidity.

Stimulation of α7-nAChRs coordinates autophagy and apoptosis signaling in experimental knee osteoarthritis

Osteoarthritis (OA) is the most common chronic joint disease in the elderly population. Growing evidence indicates that a balance between autophagy and apoptosis in chondrocytes plays a key role in OA’s cartilage degradation. Thus, drugs targeting the balance between apoptosis and autophagy are potential therapeutic approaches for OA treatment. In previous studies, we found that the activation of α7 nicotinic acetylcholine receptors (α7-nAChRs) alleviated monosodium iodoacetate (MIA)-induced joint degradation and osteoarthritis pain. To explore the potential functions of α7-nAChRs in autophagy and apoptosis signaling in knee OA, we compared the expression of α7-nAChRs in human knee articular cartilage tissues from normal humans and OA patients. We found that knee joint cartilage tissues of OA patients showed decreased α7-nAChRs and an imbalance between autophagy and apoptosis. Next, we observed that α7-nAChRs deficiency did not affect cartilage degradation in OA development but reversed the beneficial effects of nicotine on mechanical allodynia, cartilage degradation, and an MIA-induced switch from autophagy to apoptosis. Unlike in vivo studies, we found that primary chondrocytes from α7-nAChRs knockout (KO) mice showed decreased LC3 levels under normal conditions and were more sensitive toward MIA-induced apoptosis. Finally, we found that α7-nAChRs deficiency increased the phosphorylation of mTOR after MIA treatment, which can also be observed in OA patients’ tissues. Thus, our findings not only confirmed that nicotine alleviated MIA-induced pain behavior and cartilage degradation via stimulating the α7-nAChRs/mTOR signal pathway but found the potential role of α7-nAChRs in mediating the balance between apoptosis and autophagy.

The cholinergic system in joint health and osteoarthritis: a narrative-review

Osteoarthritis (OA) poses a major health and economic burden worldwide due to an increasing number of patients and the unavailability of disease-modifying drugs. In this review, the latest understanding of the involvement of the cholinergic system in joint homeostasis and OA will be outlined. First of all, the current evidence on the presence of the cholinergic system in the normal and OA joint will be described. Cholinergic innervation as well as the non-neuronal cholinergic system are detected. In a variety of inflammatory diseases, the classic cholinergic anti-inflammatory pathway lately received a lot of attention as via this pathway cholinergic agonists can reduce inflammation. The role of this cholinergic anti-inflammatory pathway in the context of OA will be discussed. Activation of this pathway improved the progression of the disease. Secondly, chondrocyte hypertrophy plays a pivotal role in osteophyte formation and OA development; the impact of the cholinergic system on hypertrophic chondroblasts and endochondral ossification will be evaluated. Cholinergic stimulation increased chondrocyte proliferation, delayed chondrocyte differentiation and caused early mineralisation. Moreover, acetylcholinesterase and butyrylcholinesterase affect the endochondral ossification via an acetylcholine-independent pathway. Thirdly, subchondral bone is critical for cartilage homeostasis and metabolism; the cholinergic system in subchondral bone homeostasis and disorders will be explored. An increase in osteoblast proliferation and osteoclast apoptosis is observed. Lastly, current therapeutic strategies for OA are limited to symptom relief; here the impact of smoking on disease progression and the potential of acetylcholinesterase inhibitors as candidate disease-modifying drug for OA will be discussed.

Does smoking cessation increase risk of knee replacement? a general population-based cohort study

OBJECTIVE

Smoking represents a major issue for global public health. Owing to methodologic challenges, findings of an association between smoking and risk of knee osteoarthritis (OA) are inconsistent. We sought to assess the relation of onset of smoking cessation to the risk of OA sequelae, i.e., knee replacement, and to perform sub-cohort analysis according to weight change after smoking cessation.

DESIGN

Using The Health Improvement Network, we conducted a cohort study to examine the association between smoking cessation and risk of knee replacement among patients with knee OA. Participants who stopped smoking were further grouped into three sub-cohorts: weight gain (body mass index [BMI] increased>1.14 kg/m²), no substantial weight change (absolute value of BMI change<1.14 kg/m²), and weight loss (BMI loss>1.14 kg/m²) after smoking cessation.

RESULTS

We identified 108 cases of knee replacement among 1,054 recent quitters (26.7/1,000 person-years) and 1,108 cases among 15,765 current smokers (17.4/1,000 person-years). The rate difference of knee replacement in recent quitter cohort vs current smoker cohort was 10.4 (95% confidence interval [CI]:5.3-15.6)/1,000 person-years and the adjusted hazard ratio (HR) was 1.30 (95%CI:1.05-1.59). Compared with current smokers, risk of knee replacement was higher among quitters with weight gain (HR = 1.42,95%CI:1.01-1.98), but not among those with no substantial weight change (HR = 1.29,95%CI:0.90-1.83) or those with weight loss (HR = 1.11,95%CI:0.71-1.75).

CONCLUSIONS

Our large population-based cohort study provides the first evidence that smoking cessation was associated with a higher risk of knee replacement among individuals with knee OA, and such an association was due to weight gain after smoking cessation.

Exposure to second-hand cigarette smoke exacerbates the progression of osteoarthritis in a surgical induced murine model

Osteoarthritis (OA), formerly understood to be a result of passive wear, is now known to be associated with chronic inflammation. Cigarette smoking promotes systemic inflammation and has been implicated in increased joint OA incidence in some studies, though the recent observational data on the association are contradictory. We hypothesize that second-hand smoke (SHS) treatment will increase the incidence of OA in a mouse model that has been subjected to a surgical destabilization of the medial meniscus (DMM). To test this hypothesis, we applied either SHS treatment or room air (RA) to mice for 28 days post-DMM surgery. Histopathology findings indicated that the knees of SHS mice exhibited more severe OA than their control counterparts. Increased expression of matrix metalloprotease-13 (MMP-13), an important extracellular protease known to degrade articular cartilage, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), an intracellular effector of inflammatory pathways, were observed in the SHS group. These findings provide greater understanding and evidence for a detrimental role of cigarette smoke on OA progression and systemic inflammation.

Cardiometabolic traits mediating the effect of education on osteoarthritis risk: a Mendelian randomization study

OBJECTIVE

To investigate which cardiometabolic factors underlie clustering of osteoarthritis (OA) with cardiovascular disease, and the extent to which these mediate an effect of education.

DESIGN

Genome-wide association study (GWAS) of OA was performed in UK Biobank (60,800 cases and 328,251 controls) to obtain genetic association estimates for OA risk. Genetic instruments and association estimates for body mass index (BMI), low-density lipoprotein cholesterol (LDL-C), systolic blood pressure (SBP), smoking and education were obtained from existing GWAS summary data (sample sizes 188,577-866,834 individuals). Two-sample Mendelian randomization (MR) analyses were performed to investigate the effects of exposure traits on OA risk. MR mediation analyses were undertaken to investigate whether the cardiometabolic traits mediate any effect of education on OA risk.

RESULTS

MR analyses identified protective effects of higher genetically predicted education (main MR analysis odds ratio (OR) per standard deviation increase 0.59, 95% confidence interval (CI) 0.54-0.64) and LDL-C levels (OR 0.94, 95%CI 0.91-0.98) on OA risk, and unfavourable effects of higher genetically predicted BMI (OR 1.82, 95%CI 1.73-1.92) and smoking (OR 2.23, 95%CI 1.85-2.68). There was no strong evidence of an effect of genetically predicted SBP on OA risk (OR 0.98, 95% CI 0.90-1.06). The proportion of the effect of genetically predicted education mediated through genetically predicted BMI and smoking was 35% (95%CI 13-57%).

CONCLUSIONS

These findings highlight education, obesity and smoking as common mechanisms underlying OA and cardiovascular disease. These risk factors represent clinical and public health targets for reducing multi-morbidity related to the burden these common conditions.

Development of a model for predicting the 4-year risk of symptomatic knee osteoarthritis in China: a longitudinal cohort study

Objectives

We aimed to develop a model for predicting the 4-year risk of knee osteoarthritis (KOA) based on survey data obtained via a random, nationwide sample of Chinese individuals.

Methods

Data was analyzed from 8193 middle-aged and older adults included in the China Health and Retirement Longitudinal Study (CHARLS). The incident of symptomatic KOA was defined as participants who were free of symptomatic KOA at baseline (CHARLS2011) and diagnosed with symptomatic KOA at the 4-year follow-up (CHARLS2015). The effects of potential predictors on the incident of KOA were estimated using logistic regression models and the final model was internally validated using the bootstrapping technique. Model performance was assessed based on discrimination—area under the receiver operating characteristic curve (AUC)—and calibration.

Results

A total of 815 incidents of KOA were identified at the 4-year follow-up, resulting in a cumulative incidence of approximately 9.95%. The final multivariable model included age, sex, waist circumference, residential area, difficulty with activities of daily living (ADLs)/instrumental activities of daily living (IADLs), history of hip fracture, depressive symptoms, number of chronic comorbidities, self-rated health status, and level of moderate physical activity (MPA). The risk model showed good discrimination with AUC = 0.719 (95% confidence interval [CI] 0.700–0.737) and optimism-corrected AUC = 0.712 after bootstrap validation. A satisfactory agreement was observed between the observed and predicted probability of incident symptomatic KOA. And a simple clinical score model was developed for quantifying the risk of KOA.

Conclusion

Our prediction model may aid the early identification of individuals at the greatest risk of developing KOA within 4 years.

A molecular quantitative trait locus map for osteoarthritis

Osteoarthritis causes pain and functional disability for over 500 million people worldwide. To develop disease-stratifying tools and modifying therapies, we need a better understanding of the molecular basis of the disease in relevant tissue and cell types. Here, we study primary cartilage and synovium from 115 patients with osteoarthritis to construct a deep molecular signature map of the disease. By integrating genetics with transcriptomics and proteomics, we discover molecular trait loci in each tissue type and omics level, identify likely effector genes for osteoarthritis-associated genetic signals and highlight high-value targets for drug development and repurposing. These findings provide insights into disease aetiopathology, and offer translational opportunities in response to the global clinical challenge of osteoarthritis.

Incidence and progression of ankle osteoarthritis: The johnston county osteoarthritis project

OBJECTIVE

To determine the incidence and progression of ankle osteoarthritis (OA) and associated risk factors in a community-based cohort of African Americans and whites.

METHODS

Data were from 541 participants who had standardized lateral and mortise radiography of the ankles in weight bearing at baseline (2013-2015) and follow-up (2017-2018). Incident radiographic ankle OA (rAOA) was defined as a Kellgren-Lawrence grade (KLG) ≥ 1 at follow-up among ankles with baseline KLG < 1; progressive rAOA was a ≥ 1 KLG increase at follow-up among ankles with KLG ≥ 1 at baseline. Symptoms were assessed using self-reported pain, aching, and stiffness (PAS) on most days and the Foot and Ankle Outcome Score (FAOS) symptoms subscale. Ankle-level logistic regression models were used to assess associations of ankle outcomes with covariates (age, sex, race, body mass index [BMI], smoking, number of symptomatic joints, comorbidities, prior ankle injury, and knee or foot OA).

RESULTS

Among ankles without rAOA at baseline, 28% developed incident rAOA, 37% had worsening FAOS symptoms, and 7% had worsening PAS. Incident rAOA and worsening ankle symptoms were associated with higher BMI and symptoms in other joints. Among ankles with baseline rAOA, 4% had progressive rAOA, 35% had worsening of FAOS symptoms, and 9% had worsening PAS. rAOA progression was associated with ankle injury and concomitant knee or foot OA; worsening of symptoms was associated with higher BMI and other symptomatic joints.

CONCLUSIONS

Not all ankle OA is post-traumatic. Smoking prevention/cessation, a healthy weight, and injury prevention may be methods for reducing the incidence and progression of rAOA.

The Role of the Non-neuronal Cholinergic System in Inflammation and Degradation Processes in Osteoarthritis

OBJECTIVE

The non-neuronal cholinergic system represents non-neuronal cells that have the biochemical machinery to synthetize de novo and/or respond to acetylcholine (ACh). We undertook this study to investigate this biochemical machinery in chondrocytes and its involvement in osteoarthritis (OA).

METHODS

Expression of the biochemical machinery for ACh metabolism and nicotinic ACh receptors (nAChR), particularly α7-nAChR, in human OA and murine chondrocytes was determined by polymerase chain reaction and ligand-binding. We investigated the messenger RNA expression of the human duplicate α7-nACh subunit, called CHRFAM7A, which is responsible for truncated α7-nAChR. We assessed the effect of nAChR on chondrocytes activated by interleukin-1β (IL-1β) and the involvement of α7-nAChR using chondrocytes from wild-type (WT) and α7-deficient Chrna7^-/- mice. The role of α7-nAChR in OA was explored after medial meniscectomy in WT and Chrna7^-/- mice.

RESULTS

Human and murine chondrocytes express the biochemical partners of the non-neuronal cholinergic system and a functional α7-nAChR at their cell surface (n = 5 experiments with 5 samples each). The expression of CHRFAM7A in human OA chondrocytes (n = 23 samples) correlated positively with matrix metalloproteinase 3 (MMP-3) (r = 0.38, P < 0.05) and MMP-13 (r = 0.48, P < 0.05) expression. Nicotine decreased the IL-1β-induced IL-6 and MMP expression, in a dose-dependent manner, in WT chondrocytes but not in Chrna7^-/- chondrocytes. Chrna7^-/- mice that underwent meniscectomy (n = 7) displayed more severe OA cartilage damage (mean ± SD Osteoarthritis Research Society International [OARSI] score 4.46 ± 1.09) compared to WT mice that underwent meniscectomy (n = 9) (mean ± SD OARSI score 3.05 ± 0.9; P < 0.05).

CONCLUSION

The non-neuronal cholinergic system is functionally expressed in chondrocytes. Stimulation of nAChR induces antiinflammatory and anticatabolic activity through α7-nAChR, but the anticatabolic activity may be mitigated by truncated α7-nAChR in human chondrocytes. In vivo experiments strongly suggest that α7-nAChR has a protective role in OA.

Impact of smoking on femorotibial and hip osteoarthritis progression: 3-year follow-up data from the KHOALA cohort

OBJECTIVES

To evaluate the clinical and structural impact of smoking on knee and hip osteoarthritis at baseline and after 3years.

METHODS

Observational data on the progressive effects of smoking at baseline and after 3years were collected from The Knee and Hip Osteoarthritis Long-Term Assessment cohort comprising a French population of patients aged 40-75years with symptomatic lower limb osteoarthritis. Clinical (the Western Ontario and McMaster Universities Arthritis Index and Harris scores) and structural (radiography for osteophyte detection and joint-space narrowing assessment) were conducted. The tobacco usage categories were 'never smoker', 'former smoker', and 'current smoker'.

RESULTS

Of the 873 subjects included, 215 (25%) were former smokers and 119 (14%) were current smokers. Multivariate analyses revealed that former and current smokers had fewer knee osteophytes in the medial compartment at baseline (odds ratio [OR]=0.64 [0.41-0.99] and 0.63 [0.36-1.11], respectively), lower osteophyte development in the lateral condyle after 3years (OR=011 [0.03-0.45] and 0.15 [0.03-0.97]), and lower osteophyte development in the lateral tibial plateau after 3years (OR=0.22 [0.06-0.75] and 0.68 [0.14-3.35]). Higher tobacco consumption and longer duration of consumption were significantly associated with fewer knee osteophytes at baseline and lower osteophyte development at 3years.

CONCLUSION

Although cigarette smoking did not influence knee function, pain, or the need for replacement surgery, current and former smokers developed fewer osteophytes. This relationship may be linked to the quantity and duration of consumption. Our results provide further insight into the smoking-related pathophysiology of osteoarthritis.

Correlation between radiographic knee osteoarthritis and lifetime cigarette smoking amount in a Korean population: A cross-sectional study

Although the inverse correlation between smoking and degenerative arthritis is controversial, quantitative analysis of the correlation between lifetime cigarette smoking amount and degenerative arthritis has not been performed. We investigated the correlation between knee radiographic osteoarthritis (ROA) and lifetime cigarette smoking amount in the general population.This cross-sectional study used the Fifth and Sixth Korean National Health and Nutrition Examination Survey (2010-2013) data. Subjects included 11,638 community-dwelling adults aged ≥50 years. Knee ROA was defined as a Kellgren/Lawrence grade ≥2 on plain radiography. Lifetime cigarette smoking amount was calculated in terms of pack-year and further divided into quartile groups. Independent correlation between smoking and knee ROA was determined using odds ratios (OR) adjusted for age, sex, obesity, physical activity, and household income on multivariate logistic regression analysis.Knee ROA prevalence was 37.3%; prevalence of lifetime cigarette smokers was 26.0%. Subjects with knee ROA had higher mean age, female sex ratio, and body mass index but lower physical activity level. The adjusted logistic regression model revealed that female sex (OR, 2.110; 95% confidence interval [CI], 1.895-2.349) was significantly associated with knee ROA. Older age, obesity, and lower household income were positively correlated with knee ROA. Second-and fourth-quartile groups of smokers had the lower ROA prevalence than never-smokers (OR, 0.800; 95% CI, 0.643-0.99; OR, 0.812; 95% CI, 0.684-0.965, respectively).An inverse correlation with knee ROA was confirmed in mid-light to heavy smokers. Prospective studies are needed to reveal whether knee ROA involves smoking.

Prevalence of symptomatic osteoarthritis in Spain: EPISER2016 study

INTRODUCTION

The Spanish Society of Rheumatology carried out the EPISER2000 study in 2000 to determine the prevalence of osteoarthritis and other rheumatic diseases in the Spanish population. Recent sociodemographic changes and lifestyle habits in Spain justified updating the epidemiological data on osteoarthritis and other rheumatic diseases (EPISER2016-study).

OBJECTIVE

To estimate the prevalence of symptomatic osteoarthritis of the cervical spine, lumbar spine, hip, knee and hand in the adult population in Spain.

MATERIAL AND METHODS

Cross-sectional population-based study. A multistage and stratified random cluster sampling was carried out. The participants were contacted by telephone to complete an osteoarthritis screening questionnaire. A rheumatologist confirmed or discarded the diagnosis. The ACR-clinical-criteria were used to diagnose hand-osteoarthritis and the ACR-clinical-radiological criteria to diagnose knee- and hip-osteoarthritis. To estimate the prevalence and its 95% confidence interval, weights were calculated according to the probability of selection in each of the sampling stages.

RESULTS

The prevalence of osteoarthritis in Spain in one or more of the locations studied was 29.35%. The prevalence of cervical-osteoarthritis was 10.10% and of lumbar-osteoarthritis 15.52%. Both are more frequent in women and at older ages, as well as in people with low levels of education and obesity. The prevalence of hip-osteoarthritis was 5.13%, that of knee-osteoarthritis 13.83%, these are associated with female sex, overweight and obesity. The prevalence of hand osteoarthritis was 7.73%. It is more frequent in women, who are obese, with a low educational level and who are older.

CONCLUSION

The EPISER2016 study is the first to analyse the prevalence of symptomatic osteoarthritis in 5 locations (cervical, lumbar, knee, hip and hands) in Spain. Lumbar spine osteoarthritis is the most prevalent.

Association of trajectory of body mass index with knee pain risk in Japanese middle-aged women in a prospective cohort study: the Japan Nurses' Health Study

OBJECTIVES

To investigate whether body mass index (BMI) trajectory, lifestyle and reproductive factors are associated with knee pain risk among middle-aged women.

DESIGN

Prospective study of the Japan Nurses' Health Study (JNHS).

SETTING

The JNHS investigates the health of female nurses in Japan. Biennial follow-up questionnaires are mailed to the participants.

PARTICIPANTS

The 7434 women aged over 40 years who responded to the 10-year self-administered follow-up questionnaire.

PRIMARY OUTCOME MEASURE

Self-reported knee pain at the 10-year follow-up was the primary outcome. We analysed BMI (normal or overweight) trajectory data from a baseline survey to the 10-year follow-up survey using group-based trajectory modelling. Exposure measurements were BMI trajectory, BMI at age 18 years, lifestyle variables and reproductive history.

RESULTS

BMI trajectories from baseline to the 10-year follow-up were divided into four groups: remained normal, remained overweight, gained weight or lost weight. At the 10-year follow-up, 1281 women (17.2%) reported knee pain. Multivariable logistic regression analysis revealed that compared with the remained normal group, multivariable-adjusted ORs (95% CI) of knee pain were 1.93 (1.60 to 2.33) for the remained overweight group, 1.60 (1.23 to 2.08) for the gained weight group and 1.40 (0.88 to 2.21) for the lost weight group. The attributable risk percent (95% CI) of the remained overweight group was 48.1% (37.3% to 57.0%) compared with the reference group of remained normal. Alcohol intake at baseline was significantly associated with knee pain.

CONCLUSIONS

The lost weight group had a lower risk than the remained overweight group and the gained weight group and did not carry statistically significant risks for knee pain. Weight reduction and maintaining a normal BMI in middle age was important for preventing knee pain in women.

Causal association between smoking behavior and the decreased risk of osteoarthritis: a Mendelian randomization

OBJECTIVE

This study aimed to examine whether smoking behavior is causally associated with osteoarthritis.

METHODS

A two-sample Mendelian randomization (MR) analysis using the inverse-variance weighted (IVW), weighted median, and MR-Egger regression methods was performed. We used the publicly available summary statistics datasets of smoking behavior genome-wide association studies (GWASs; n = 85,997) as an exposure, and a GWAS in 7410 patients with osteoarthritis in the arcOGEN study and 11,009 controls of European ancestry as an outcome.

RESULTS

We selected four single nucleotide polymorphisms (SNPs) from GWASs of smoking behavior as instrumental variables (IVs) to improve inference. These SNPs were located at CHRNA3 (rs1051730), SLC25A5P5A9 (rs215614), CHRNB3 (rs6474412), and CYP2B6 (rs7260329). The IVW method showed evidence to support an inverse causal association between smoking behavior and osteoarthritis in the knee and hip (beta = -0.056, standard error [SE] = 0.027, p = 0.035). MR-Egger regression revealed that directional pleiotropy was unlikely to be biasing the result (intercept = -0.005; p = 0.848), but showed no causal association between smoking behavior and osteoarthritis (beta = -0.048, SE = 0.048, p = 0.427). However, the weighted median approach yielded evidence of a negative causal association between smoking behavior and osteoarthritis (beta = -0.056, SE = 0.028, p = 0.046). Cochran's Q test and the funnel plot indicated no evidence of heterogeneity between IV estimates based on the individual variants.

CONCLUSION

The results of MR analysis support that smoking behavior was causally associated with a reduced risk of osteoarthritis.

Modifiable factors associated with symptomatic knee osteoarthritis: The Murakami cohort study

OBJECTIVES

Modifiable risk factors for knee osteoarthritis (OA) have not been studied in detail. This study aimed to determine lifestyle-related modifiable factors of symptomatic knee osteoarthritis in an East Asian population.

STUDY DESIGN

This 5-year cohort study involved 11,091 individuals (age range 40-72 years) living in the Murakami region of Niigata, Japan, who did not have a history of knee OA. At baseline, information on sociodemographic characteristics, body size, lifestyle, and living condition was obtained using a self-administered questionnaire.

MAIN OUTCOME MEASURES

Incident symptomatic knee OA observed at hospitals and orthopaedic clinics in the five years to 2016. Clinical grades of knee OA were based on the Kellgren-Lawrence scale. P for trend was assessed to examine linear associations between predictors and the outcome in multiple logistic regression analysis.

RESULTS

The mean age of participants was 58.1 (SD 9.3) years. The number of cases of grade 2 or more incident knee OA was 429. In men, older age (P for trend < 0.0001), higher BMI (P for trend < 0.0001), higher METs score (P for trend = 0.0150), less smoking (P for trend = 0.0249), and lower green tea consumption (P for trend = 0.0437) were associated with incident knee OA. In women, older age (P for trend < 0.0001), higher BMI (P for trend < 0.0001), and alcohol consumption (P = 0.0153) were associated with incident knee OA.

CONCLUSIONS

Several lifestyle-related factors were found to be associated with incident knee OA and exhibited sex-dependent differences. In particular, higher consumption of green tea was associated with a lower incidence of knee OA in men.

Risk factors of knee osteoarthritis: A case-control study

Background and Objective

Knee osteoarthritis is one of the most common rheumatologic problems. To investigate risk factors related to the knee osteoarthritis a case-control study was performed using cases diagnosed in the Community Oriented Program for Control of Rheumatic Diseases (COPCORD) study, stage I.

Methods

Using data from the 2012 COPCORD study, stage-I that was conducted in Sanandaj, northwestern of Iran, we runned a case-control study in 2014-2015. Cases were 700 knee osteoarthritis using American College of Rheumatology (ACR) criteria, frequency matched with 700 healthy controls that were randomly selected from the general population.

Results

In multivariate analysis, statistical significant relation was observed between knee OA and some studied factors such as body mass index (P <0.001), lodging (living in highland vs. plain) (P <0.001), type of used toilet (regular vs. toilet) (P <0.001), history of using high-heeled shoes (>3 cm) (P = 0.005), history of knee Injury (P = 0.04), history of lower limb fracture (P = 0.02), Number of pregnancies (P <0.001) and history of pain and swelling (lasting for one months) (P = 0.04).

Conclusions

Living in highland area, using regular toilet, having knee injury and lower limb fracture in the past were most significant associated factors with occurrence of knee osteoarthritis.

The association between smoking and knee osteoarthritis in a cohort of Danish patients undergoing knee arthroscopy

Background

It has been suggested that smoking is associated with reduced risk of knee osteoarthritis (OA). However, supplementary studies are needed to further investigate any such potential association. Thus, our aim was to examine the relationship between smoking and early or more established knee OA in a cohort of relatively young patients with meniscal tears.

Methods

This cross-sectional study included 620 participants from the Knee Arthroscopy Cohort Southern Denmark (KACS) undergoing knee arthroscopy for a meniscal tear (mean age 49.2 (18.0–76.8) years). Recruitment of patients was performed between February 1, 2013, and January 31, 2015, at four different hospitals in Denmark. We defined early or more established knee OA as the combination of patient-reported frequent knee pain, degenerative meniscal tissue and presence of cartilage defects assessed by the operating surgeons. The relationship between smoking status and knee OA was examined by risk ratio (RR) with a 95% confidence interval (CI), estimated from logistic regression adjusted for age, sex, BMI, education, work status and level of physical activity.

Results

The prevalence of early or more established knee OA was 37.7% in current smokers and 45.0% in non-smokers. We found no statistically significant association between current smoking and knee OA (adjusted RR 1.09, 95% CI 0.91–1.30).

Conclusions

This study found no relationship between current smoking and early or more established knee OA in a cohort of patients undergoing arthroscopic meniscal surgery. Thus, the inverse association between smoking and knee OA that has been suggested by previous studies was not confirmed.

Estrogen reverses nicotine-induced inflammation in chondrocytes via reducing the degradation of ECM

PROBLEM

Osteoarthritis (OA) is a chronic disease with a very high incidence and the pathology of which is quite complex. Epidemiological investigation showed that OA may be related to smoking and estrogen levels, but there are few studies focused on the cross-effect of these two factors. This research aims to investigate the molecular mechanism of nicotine and estrogen effects on chondrocytes to study the effect of smoking on the incidence of osteoarthritis in women.

METHOD OF THE STUDY

Nicotine was added to obtain inflammatory supernatants of macrophages, which were used to induce chondrocyte inflammation. Toluidine staining and immunohistochemistry were used to detect the extracellular matrix (ECM) of chondrocytes, while the important proteins in the metabolism of chondrocytes were detected by Western blot.

RESULTS

Nicotine-induced inflammatory supernatant promoted the degradation of ECM, such as type II collagen, aggrecan and proteoglycan 4. While in the presence of physiological concentrations of estrogen, this destructive effect is reversed. On the molecular level, estrogen (17β-estradiol, 1 nmol/L) can inhibit the matrix degrading enzymes and promote the transforming growth factor (TGF)-β1 pathway which is involved in matrix synthesis. However, in the presence of inflammatory induction, although estrogen could still inhibit the expression of matrix degrading enzymes, it inhibited the TGF-β1 pathway. Moreover, the different inflammatory factors in the inflammatory supernatant, mainly tumor necrosis factor-α, interleukin-1β, had different effects on the metabolic processes of chondrocytes.

CONCLUSION

Estrogen reverses nicotine-induced inflammation mainly via reducing the degradation of ECM. The cross-effect of estrogen and inflammatory factor inhibitors can be a potential clinical reference for OA patients.

Update on the epidemiology, risk factors and disease outcomes of osteoarthritis

Osteoarthritis (OA) is the most frequent form of arthritis and a leading cause of pain and disability worldwide. OA can affect any synovial joint, although the hip, knee, hand, foot and spine are the most commonly affected sites. Knowledge about the occurrence and risk factors for OA is important to define the clinical and public health burden of the disease to understand mechanisms of disease occurrence and may also help to inform the development of population-wide prevention strategies. In this article, we review the occurrence and risk factors for OA and also consider patient-reported outcome measures that have been used for the assessment of the disease.