A retrospective cohort study of cigarette smoking and risk of rheumatoid arthritis in female health professionals

Association between Life's Essential 8 and rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) exhibits a robust association with cardiovascular disease. Our study aims to elucidate the correlation between RA prevalence and Life's Essential 8 (LE8), a recently updated measure of cardiovascular health (CVH).

METHODS AND RESULTS

We conducted a population-based cross-sectional study using data from the National Health and Nutrition Examination Survey (NHANES) spanning from 2007 to 2018. Utilizing multivariable logistic and restricted cubic spline models, we explored the relationship between LE8 and RA. Our analysis included 17,263 participants. We found that higher LE8 scores were closely associated with reduced odds of RA (odds ratio for each 10-point increase, 0.91 (95% CI, 0.75-0.87)). Furthermore, we observed a nonlinear association between LE8 and RA after adjusting for potential confounders. Specifically, higher scores for sleep health, nicotine exposure, body mass index, and blood pressure within the LE8 components were significantly correlated with a lower risk of RA. Additionally, the inverse relationship between LE8 scores and RA was notably stronger among young and female individuals.

CONCLUSION

Our findings suggest a negative correlation between LE8 and RA prevalence, indicating that adherence to the lifestyle defined by LE8 may confer protective effects against RA.

The peculiar features, diversity and impact of citrulline-reactive autoantibodies

Since entering the stage 25 years ago as a highly specific serological biomarker for rheumatoid arthritis, anti-citrullinated protein antibodies (ACPAs) have been a topic of extensive research. This hallmark B cell response arises years before disease onset, displays interpatient autoantigen variability, and is associated with poor clinical outcomes. Technological and scientific advances have revealed broad clonal diversity and intriguing features including high levels of somatic hypermutation, variable-domain N-linked glycosylation, hapten-like peptide interactions, and clone-specific multireactivity to citrullinated, carbamylated and acetylated epitopes. ACPAs have been found in different isotypes and subclasses, in both circulation and tissue, and are secreted by both plasmablasts and long-lived plasma cells. Notably, although some disease-promoting features have been reported, results now demonstrate that certain monoclonal ACPAs therapeutically block arthritis and inflammation in mouse models. A wealth of functional studies using patient-derived polyclonal and monoclonal antibodies have provided evidence for pathogenic and protective effects of ACPAs in the context of arthritis. To understand the roles of ACPAs, one needs to consider their immunological properties by incorporating different facets such as rheumatoid arthritis B cell biology, environmental triggers and chronic antigen exposure. The emerging picture points to a complex role of citrulline-reactive autoantibodies, in which the diversity and dynamics of antibody clones could determine clinical progression and manifestations.

Exposure to air pollutants and rheumatoid arthritis biomarkers: A scoping review

INTRODUCTION

Rheumatoid arthritis (RA) is a common autoimmune disease with a complex and poorly understood etiology that includes genetic, hormonal, and environmental factors.

OBJECTIVE

Our objective was to assess current literature that investigated the association between exposure to environmental and occupational air pollutants and RA-related biomarkers rheumatoid factor (RF) and anti-citrullinated peptide antibody (ACPA).

DESIGN

PubMed and Web of Science were used to identify epidemiological studies that measured or estimated air pollution and at least one RA biomarker. Information was charted for comparison of evidence, including pollutant(s) studied, exposure assessment, biomarker measurement, analysis method, study population, size, dates, adjustment variables, and findings.

RESULTS

Several common air pollutants (including two mixtures) and a few dozen occupational inhalants were assessed in 13 eligible studies. Associations between industrial sulfur dioxide and particulate matter less than 2.5 µm in diameter with ACPA were observed most frequently, including associations between residential proximity to pollution sources and ACPA positivity. Consistency of associations with other pollutants was either not observed or limited to single studies. Three studies evaluated the modifying impact of SE alleles (a genetic factor associated with RA) and found that pollutant associations were stronger among participants positive for SE alleles.

CONCLUSION

Based on mixed results, there was no consistent link between any single pollutant and RA-related biomarker outcomes. Comparisons across studies were limited by differences in study populations (e.g., by RA status, by sociodemographic groups) and study design (including designs focused on different sources of air pollution, methodological approaches with varying levels of potential exposure misclassification, and assessments of inconsistent biomarker cut-points). However, given that multiple studies reported associations between exposure to air pollution and RA biomarkers, continued exploration utilizing studies that can be designed with a more robust causal framework, including continued consideration of effect modification by genetic status, may be necessary.

Modifiable risk factors linked to the development of rheumatoid arthritis: evidence, immunological mechanisms and prevention

Rheumatoid Arthritis (RA) is a common autoimmune disease that targets the synovial joints leading to arthritis. Although the etiology of RA remains largely unknown, it is clear that numerous modifiable risk factors confer increased risk to developing RA. Of these risk factors, cigarette smoking, nutrition, obesity, occupational exposures and periodontal disease all incrementally increase RA risk. However, the precise immunological mechanisms by which these risk factors lead to RA are not well understood. Basic and translational studies have provided key insights into the relationship between inflammation, antibody production and the influence in other key cellular events such as T cell polarization in RA risk. Improving our general understanding of the mechanisms which lead to RA will help identify targets for prevention trials, which are underway in at-risk populations. Herein, we review the modifiable risk factors that are linked to RA development and describe immune mechanisms that may be involved. We highlight the few studies that have sought to understand if modification of these risk factors reduces RA risk. Finally, we speculate that modification of risk factors may be an appealing avenue for prevention for some at-risk individuals, specifically those who prefer lifestyle interventions due to safety and economic reasons.

Impact of a Rheumatology Clinic Protocol on Tobacco Cessation Quit Line Referrals

OBJECTIVE

Smoking increases cardiopulmonary and rheumatic disease risk, yet tobacco cessation intervention is rare in rheumatology clinics. This study aimed to implement a rheumatology staff-driven protocol, Quit Connect, to increase the rate of electronic referrals (e-referrals) to free, state-run tobacco quit lines.

METHODS

We conducted a quasi-experimental cohort study of Quit Connect at 3 rheumatology clinics comparing tobacco quit line referrals from 4 baseline years to referrals during a 6-month intervention period. Nurses and medical assistants were trained to use 2 standardized electronic health record (EHR) prompts to check readiness to quit smoking within 30 days, advise cessation, and connect patients using tobacco quit line e-referral orders. Our objective was to use EHR data to examine the primary outcome of tobacco quit line referrals using pre/post design.

RESULTS

Across 54,090 pre- and post-protocol rheumatology clinic visits, 4,601 were with current smokers. We compared outcomes between 4,078 eligible pre-implementation visits and 523 intervention period visits. Post-implementation, the odds of tobacco quit line referral were 26-fold higher compared to our pre-implementation rate (unadjusted odds ratio [OR] 26 [95% confidence interval (95% CI) 6-106]). Adjusted odds of checking readiness to quit in the next 30 days increased over 100-fold compared to pre-implementation (adjusted OR 132 [95% CI 99-177]). Intervention led to e-referrals for 71% of quit-ready patients in <90 seconds; 24% of referred patients reported a quit attempt.

CONCLUSION

Implementing Quit Connect in rheumatology clinics was feasible and improved referrals to a state-run tobacco quit line. Given the importance of smoking cessation to reduce cardiopulmonary and rheumatic disease risk, future studies should investigate disseminating cessation protocols like Quit Connect that leverage tobacco quit lines.

The association between smoking and the development of rheumatoid arthritis: a population-based case-control study

INTRODUCTION

Smoking is one of the few modifiable risk factors associated with the development of rheumatoid arthritis (RA). Most published data are over 10 years old, and none included Mediterranean populations. We therefore took advantage of primary care routinely collected data to study the association between smoking and the development of RA in the general population of Catalonia, Spain.

METHODS

We conducted a case-control study including all patients with a new diagnosis of RA registered in the SIDIAP database between 01/01/2008 and 31/12/2018; and matched them to up to 1:5 controls by age, gender and general practitioner. Smoking was classified by primary care staff into never, ex- or current smoking. Odds Ratios and 95% confidence intervals for the association between current and ex-smoking (compared to never smoking) and RA were estimated using conditional logistic regression adjusted for potential confounders.

RESULTS

A total of 13,920 RA cases and 69,535 controls were included. Compared with never smokers, current and ex-smokers were at increased risk of RA, with adjusted OR of 1.28 [95% CI 1.20-1.37] and OR 1.19 [1.12-1.26] respectively.

CONCLUSION

Our findings confirm an association between smoking and the risk of developing RA. The effect seems to prevail in the long-term and even in ex-smokers for 2 or more years after smoking cessation. More research is needed on the effects of smoking discontinuation on RA prevention and related outcomes.

Periodontitis and rheumatoid arthritis: What have we learned about their connection and their treatment?

Rheumatoid arthritis and periodontitis are chronic inflammatory diseases defined respectively by the destruction of the articular cartilage and tooth-supporting periodontal tissues. Although the epidemiologic evidence for an association between these two diseases is still scarce, there is emerging scientific information linking specific bacterial periodontal pathogens, such as Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, in the citrullination process, leading to autoantibody formation and compromised immunotolerance of the susceptible patient to rheumatoid arthritis. In this review, we update the existing information on the evidence, not only regarding the epidemiologic association, but also the biologic mechanisms linking these two diseases. Finally, we review information emerging from intervention studies evaluating whether periodontal treatment could influence the initiation and progression of rheumatoid arthritis.

Socioeconomic inequality in patients with rheumatoid arthritis: a systematic review and meta-analysis

BACKGROUND

Rheumatoid arthritis is a chronic inflammatory and systemic autoimmune disease associated with synovial fluid inflammatory lesions and articular changes. The aim of the present study was to determine socioeconomic inequality in RA patients using a meta-analysis approach.

METHODS

A systematic search of national and international databases of SID, MagIran, Google Scholar, Cochrane, Embase, ScienceDirect, Scopus, PubMed, and Web of Science (WoS) was conducted to find articles published from 1988 to March 2020. Random effects model was used for analysis and heterogeneity of studies was investigated using I² index. Data analysis was then carried out using Comprehensive Meta-Analysis (Ver. 2).

RESULTS

A total of 51 articles with a total sample size of 48,195 individuals were included in the meta-analysis in all the components. The results showed that 18.9% (95% CI: 4.9-13.25%) of patients were single patients, 70.6% (95% CI: 63.5-76.8%) were married, 31.6% (95% CI: 24.5-39.7%) had low economic status, 52.1% (95% CI: 5.8-44.53%) had moderate economic status, level of education was below diploma in 33% (95% CI: 27.1-39.5%) of cases, 36.2% (95% CI: 27.3-46.1%) were smokers, and 8.8% (95% CI: 2.8-24.1%) of patients were unemployed.

CONCLUSION

The results of the present study indicate high socioeconomic inequality in RA patients in the main components of the study. Hence, to improve the aforementioned status and find causes and do the monitoring at all levels, appropriate solutions must be adopted by providing feedback to policy-makers.

KEY POINTS

• The results showed that 18.9% (95% CI: 4.9-13.25%) of patients were single patients. • 70.6% (95% CI: 63.5-76.8%) were married and 31.6% (95% CI: 24.5-39.7%) had low economic status. • 52.1% (95% CI: 5.8-44.53%) had moderate economic status; 36.2% (95% CI: 27.3-46.1%) were smokers.

A systematic review and meta-analysis of observational studies on the association between animal protein sources and risk of rheumatoid arthritis

OBJECTIVE

The aim of this study was to investigate the linear and nonlinear dose-response associations of animal-based dietary protein intake and risk of developing rheumatoid arthritis (RA).

METHODS

A systematic search of MEDLINE, Scopus and Embase was conducted up to October 2020. Observational studies that report risk estimates of RA for animal-based protein consumption were included. We calculated pooled relative risks (RRs) by using a random-effects model. Linear and non-linear dose-response analyses were performed to examine the dose-response relations between animal-based protein consumption and RA.

RESULTS

Seven cohort studies (n = 457,554) with 3545 incident cases and six case-control studies with 3994 cases and 5252 controls were identified. Highest compared with the lowest category of fish consumption was inversely associated with risk of RA (RR: 0.89; 95% CI, 0.80 to 0.99; I² = 0%, n = 10). Also, a 100 g/day increment in fish intake was associated with a 15% decreased risk of RA. Dose-response analysis showed a modest U-shaped association between fish consumption and incidence of RA, with the lowest risk at a fish intake of 20-30 g/day (P_{non-linearity} = 0.04). We found no significant association between consumption of red meat, poultry or dairy and the risk of RA.

CONCLUSION

The present study revealed a significant reverse association between fish consumption and risk of RA. While we observed no association between red meat, dairy or poultry consumption and risk of RA. Further well-designed prospective studies are needed to support our findings.

COVID-19 infection and rheumatoid arthritis: mutual outburst cytokines and remedies

In March 2020, COVID-19 infection caused by SARS-CoV-2 has been declared to be a global pandemic, where its complications, severity and mortality are reported to be due to the released inflammatory cytokines or the so-called cytokine storm. This is quite similar to that observed in the autoimmune and chronic inflammatory rheumatic disease, rheumatoid arthritis (RA). It was hypothesized that RA patients are at a higher risk of acquiring COVID-19; however, recent studies reported that they are not when compared to the rest of the population. In this review, we aim to highlight the mutual pathological features, cytokine profiles and risk factors between COVID-19 and RA. Also, many researchers are currently working to explore therapeutic agents that could aid in the eradication of COVID-19 infection. Due to the similarity between the inflammation status in COVID-19 and RA, many anti-rheumatic drugs such as hydroxychloroquine, tocilizumab, baricitinib and anakinra were proposed to be therapeutic modalities for COVID-19 infection.

The effect of smoking on cumulative damage in systemic lupus erythematosus: An incident cohort study

OBJECTIVES

To investigate the relationship between smoking history and pack-year exposure on the rate of end-organ damage in systemic lupus erythematosus (SLE).

METHODS

The SLE incident cohort included patients who met American College of Rheumatology (ACR) 1997 or SLE International Collaborating Clinics (SLICC) 2012 SLE criteria and had rheumatology encounters at a US academic institution (2008-16). The primary outcome was median time to SLICC/ACR damage index (SLICC/ACR-DI) increase or death. Main explanatory variables were smoking status and pack-years. Covariates included age, sex, race, ethnicity, receipt of Medicaid, neighborhood area deprivation index, and baseline SLE damage. Damage increase-free survival was evaluated by smoking status and pack-years using Kaplan-Meier and Cox proportional hazards methods.

RESULTS

Patients of Black race and Medicaid recipients were more commonly current smokers (p's < 0.05). Former smokers were older and more likely to have late-onset SLE (54% versus 33% of never and 29% of current smokers, p = 0.001). Median time to SLICC/ACR-DI increase or death was earlier in current or former compared to never smokers (4.5 and 3.4 versus 9.0 yrs; p = 0.002). In multivariable models, the rate of damage accumulation was twice as fast in current smokers (HR 2.18; 1.33, 3.57) and smokers with a >10 pack-year history (HR 2.35; 1.15, 3.64) versus never smokers.

CONCLUSIONS

In this incident SLE cohort, past or current smoking predicted new SLE damage 4-5 years earlier. After adjustment, current smokers and patients with a pack-year history of >10 years accumulated damage at twice the rate of never smokers.

The pre-clinical phase of rheumatoid arthritis: From risk factors to prevention of arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease considered as a multistep process spanning from the interaction of genetic (e.g., shared epitope or non-HLA loci), environmental and behavioral risk factors (e.g., smoking) leading to breaking immune tolerance and autoimmune processes such as the production of autoantibodies (e.g., antibodies against citrullinated proteins ACPA or rheumatoid factors, RF), development of the first symptoms without clinical arthritis, and, finally, the manifestation of arthritis. Despite the typical joint involvement in established RA, the pathogenesis of the disease likely begins far from joint structures: in the lungs or periodontium in association with citrullination, intestinal microbiome, or adipose tissue, which supports normal findings in synovial tissue in ACPA+ patients with arthralgia. The presence of ACPA is detectable even years before the first manifestation of RA. The pre-clinical phase of RA is the period preceding clinically apparent RA with ACPA contributing to the symptoms without subclinical inflammation. While the combination of ACPA and RF increases the risk of progression to RA by up to 10 times, increasing numbers of novel autoantibodies are to be investigated to contribute to the increased risk and pathogenesis of RA. With growing knowledge about the course of RA, new aspiration emerges to cure and even prevent RA, shifting the "window of opportunity" to the pre-clinical phases of RA. The clinical definition of individuals at risk of developing RA (clinically suspect arthralgia, CSA) makes it possible to unify these at-risk individuals' clinical characteristics for "preventive" treatment in ongoing clinical trials using mostly biological or conventional synthetic disease-modifying drugs. However, the combination of symptoms, laboratory, and imaging biomarkers may be the best approach to select the correct target at-risk population. The current review aims to explore different phases of RA and discuss the potential of (non)pharmacological intervention aiming to prevent RA.

Systematic Review and Meta-analysis on the Association of Occupational Exposure to Free Crystalline Silica and Rheumatoid Arthritis

• Occupational exposure to free crystalline silica and tobacco smoking are associated with an increased risk rheumatoid arthritis, with the evidence of an interaction in seropositive subjects.

• Further studies in the field are needed to support such association

We carried out a systematic search for all published epidemiological studies concerning the association between occupational exposure to free crystalline silica (FCS) and subsequent development of rheumatoid arthritis (RA). A meta-analysis was conducted on relevant studies. We searched PubMed and Embase, search engines, for original articles published (from 1960 to November 2019) in any language. In addition, we also searched reference lists of included studies manually for additional relevant articles. Finally, twelve studies were included in the meta-analysis (seven case-control cases and five cohort studies). The odds risks and 95% confidence interval (CI) were calculated using a random effect meta-analysis. A primary meta-analysis (using a random effect model)—regarding RA risk in subjects exposed to FCS—yelled to an overall OR of 1.94 (95% CI 1.46–2.58). We also conducted three further meta-analysis, taking into account the presence of autoantibodies (anti-RF or anti-ACPA) and smoking habits and found a significant association between FCS and RA in both seropositive and seronegative subjects (OR 1.74, 95% CI 1.35–2.25 and OR 1.23, 95% CI 1.06–1.4, respectively) and in seropositive subjects which were smokers (OR 3.30, 95% CI 2.40–4.54). The studies that have investigated the association between RA and occupatational exposure to FCS are still scarce and the heterogeneity between the studies remains high. Some critical limitations have been identified within studies, among which, the methods for assessing exposure stand out. Although with due caution, our results confirm the hypothesis of an association between occupational exposure to FCS and RA development. There was an interaction between FCS and tobacco smoking in RA seropositive workers.

Lifestyle factors associated with incidence of rheumatoid arthritis in US adults: analysis of National Health and Nutrition Examination Survey database and meta-analysis

OBJECTIVE

To quantify rheumatoid arthritis (RA) cases attributable to selected non-genetic risk factors.

DESIGN

National Health and Nutrition Examination Survey (NHANES) and meta-analysis.

PARTICIPANTS

US adults.

DATA SOURCES

The prevalence of exposure was obtained from NHANES. Weighted analysis was performed to account for the complex sampling design in NHANES. PubMed and Web of Science up to 31 March 2019 were searched to identify epidemiological studies reported the association between non-genetic risk factors and RA in US adults. Relative risk (RR) value and the corresponding CI were pooled by meta-analysis to evaluate the associations between modifiable risk factors and RA. Population attributable fraction (PAF) was calculated based on the prevalence and RR data.

RESULTS

The weighted percentages of former smokers, current smokers and overweight or obese people were 24.84%, 23.93% and 63.97%, and the average alcohol consumption was 51.34 g/week. In the meta-analysis, we found that former smokers (RR 1.22, 95% CI 1.10 to 1.36) and current smokers (RR 1.47, 95% CI 1.29 to 1.68) had higher risks of RA. Overweight and obese individuals had 1.27-fold (95% CI 1.09 to 1.48) increased risk of RA. Each per 50 g/week increment of alcohol consumption was associated with 8% (95% CI 0% to 16%) reduction in the risk of RA. Therefore, PAF value of smoking was 14.00% (95% CI 8.13% to 23.33%). Excess body mass index (BMI) was found to account for 14.73% (95% CI 5.45% to 23.50%) of RA incidence. The fraction of RA risk attributed by low alcohol intake was 8.21% (95% CI 0.31% to 16.39%). Collectively, we found that 32.69% (95% CI 13.41% to 50.96%) of RA cases were attributable to smoking, overweight or obesity and low alcohol drinking.

CONCLUSION

Nearly 33% of RA incidence was attributed to smoking, excess BMI and low alcohol drinking in USA. Our findings could provide a basis for developing guidelines of RA prevention and control in USA.

The Association Between Smoking and the Development of Rheumatoid Arthritis: A Population-Based Case-Control Study

INTRODUCTION

Smoking is one of the few modifiable risk factors associated with the development of rheumatoid arthritis (RA). Most published data are over 10 years old, and none included Mediterranean populations. We therefore took advantage of primary care routinely collected data to study the association between smoking and the development of RA in the general population of Catalonia, Spain.

METHODS

We conducted a case-control study including all patients with a new diagnosis of RA registered in the SIDIAP database between 01/01/2008 and 31/12/2018; and matched them to up to 1:5 controls by age, gender and general practitioner. Smoking was classified by primary care staff into never, ex- or current smoking. Odds Ratios and 95% confidence intervals for the association between current and ex-smoking (compared to never smoking) and RA were estimated using conditional logistic regression adjusted for potential confounders.

RESULTS

A total of 13,920 RA cases and 69,535 controls were included. Compared with never smokers, current and ex-smokers were at increased risk of RA, with adjusted OR of 1.28 [95% CI 1.20-1.37] and OR 1.19 [1.12-1.26] respectively.

CONCLUSION

Our findings confirm an association between smoking and the risk of developing RA. The effect seems to prevail in the long-term and even in ex-smokers for 2 or more years after smoking cessation. More research is needed on the effects of smoking discontinuation on RA prevention and related outcomes.

The Role of the Microbiome in Driving RA-Related Autoimmunity

Once referred to as "normal commensal flora" the human microbiome plays an integral role between health and disease. The host mucosal surface replete with a multitude of immune cells is a vast arena constantly sensing and responding to antigen presentation and microbial by-products. It is this key role that may allow the microbiome to prime or protect the host from autoimmune disease. Rheumatoid arthritis (RA) is a chronic, disabling inflammatory condition characterized by a complex multifactorial etiology. The presence of certain genetic markers has been proven to increase susceptibility to RA however it does not guarantee disease development. Given low concordance rates demonstrated in monozygotic twin studies there is a clear implication for the involvement of external players in RA pathogenesis. Since the historical description of rheumatoid factor, numerous additional autoantibodies have been described in the sera of RA patients. The presence of anti-cyclic citrullinated protein antibody is now a standard test, and is associated with a more severe disease course. Interestingly these antibodies are detectable in patient's sera long before the clinical signs of RA occur. The production of autoantibodies is driven by the lack of tolerance of the immune system, and how tolerance is broken is a crucial question for understanding RA development. Here we review current literature on the role of the microbiome in RA development including periodontal, gut and lung mucosa, with particular focus on proposed mechanisms of host microbiome interactions. We discuss the use of Mendelian randomization to assign causality to the microbiome and present considerations for future studies.

Patient Perspectives on Smoking Cessation and Interventions in Rheumatology Clinics

OBJECTIVE

Although smoking is a risk factor for cardiovascular and rheumatic disease severity, only 10% of rheumatology visits document cessation counseling. After implementing a rheumatology clinic protocol that increased tobacco quitline referrals 20-fold, we undertook this study to examine patients' barriers and facilitators to smoking cessation based on prior rheumatology experiences, to solicit reactions to the new cessation protocol, and to identify patient-centered outcomes or signs of cessation progress following improved care.

METHODS

We recruited 19 patients who smoke (12 with rheumatoid arthritis [RA] and 7 with systemic lupus erythematosus [SLE]) to participate in 1 of 3 semistructured focus groups. Transcripts of the focus group discussions were analyzed using thematic analysis to classify barriers, facilitators, and signs of cessation progress.

RESULTS

Participant-reported barriers and facilitators to cessation involved psychological, health-related, and social and economic factors, as well as health care messaging and resources. Commonly discussed barriers included viewing smoking as a crutch amid rheumatic disease, rarely receiving cessation counseling in rheumatology clinics, and very limited awareness that smoking can worsen rheumatic diseases or reduce efficacy of some rheumatic disease medications. Participants endorsed our cessation protocol with rheumatology-specific education and accessible resources, such as a quitline. Beyond quitting, participants prioritized knowing why and how to quit as signs of progress outcomes.

CONCLUSION

Focus groups identified themes and categories of facilitators/barriers to smoking cessation at the levels of patient and health system. Two key outcomes of improving cessation care for patients with RA and SLE were knowing why and how to quit. Emphasizing rheumatologic health benefits and cessation resources is essential when designing and evaluating rheumatology smoking cessation interventions.

The importance of differences; On environment and its interactions with genes and immunity in the causation of rheumatoid arthritis

The current review uses rheumatoid arthritis (RA) as a prominent example for how studies on the interplay between environmental and genetic factors in defined subsets of a disease can be used to formulate aetiological hypotheses that subsequently can be tested for causality using molecular and functional studies. Major discussed findings are that exposures to airways from many different noxious agents including cigarette smoke, silica dust and more interact with major susceptibility genes, mainly HLA-DR genetic variants in triggering antigen-specific immune reactions specific for RA. We also discuss how several other environmental and lifestyle factors, including microbial, neural and metabolic factors, can influence risk for RA in ways that are different in different subsets of RA.The description of these processes in RA provides the best example so far in any immune-mediated disease of how triggering of immunity at one anatomical site in the context of known environmental and genetic factors subsequently can lead to symptoms that precede the classical inflammatory disease symptoms and later contribute also to the classical RA joint inflammation. The findings referred to in the review have led to a change of paradigms for very early therapy and prevention of RA and to efforts towards what we have named 'personalized prevention'. We believe that the progress described here for RA will be of relevance for research and practice also in other immune-mediated diseases.

Asthma, Chronic Obstructive Pulmonary Disease, and Subsequent Risk for Incident Rheumatoid Arthritis Among Women: A Prospective Cohort Study

OBJECTIVE

Inflamed airways are hypothesized to contribute to rheumatoid arthritis (RA) pathogenesis due to RA-related autoantibody production, and smoking is the strongest environmental RA risk factor. However, the role of chronic airway diseases in RA development is unclear. We undertook this study to investigate whether asthma and chronic obstructive pulmonary disease (COPD) were each associated with RA.

METHODS

We performed a prospective cohort study of 205,153 women in the Nurses' Health Study (NHS, 1988-2014) and NHSII (1991-2015). Exposures were self-reported physician-diagnosed asthma or COPD confirmed by validated supplemental questionnaires. The primary outcome was incident RA confirmed by medical record review by 2 rheumatologists. Covariates (including smoking pack-years/status) were assessed via biennial questionnaires. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) for RA were estimated using Cox regression.

RESULTS

We identified 15,148 women with confirmed asthma, 3,573 women with confirmed COPD, and 1,060 incident RA cases during 4,384,471 person-years (median 24.0 years/participant) of follow-up in the NHS and NHSII. Asthma was associated with increased RA risk (HR 1.53 [95% CI 1.24-1.88]) compared to no asthma/COPD after adjustment for covariates, including smoking pack-years/status. Asthma remained associated with increased RA risk when analyzing only never-smokers (HR 1.53 [95% CI 1.14-2.05]). COPD was also associated with increased RA risk (HR 1.89 [95% CI 1.31-2.75]). The association of COPD with RA was most pronounced in the subgroup of ever-smokers age >55 years (HR 2.20 [95% CI 1.38-3.51]).

CONCLUSION

Asthma and COPD were each associated with increased risk of incident RA, independent of smoking status/intensity and other potential confounders. These results provide support for the hypothesis that chronic airway inflammation may be crucial in RA pathogenesis.

Impact and Timing of Smoking Cessation on Reducing Risk of Rheumatoid Arthritis Among Women in the Nurses' Health Studies

OBJECTIVE

To investigate the impact and timing of smoking cessation on developing rheumatoid arthritis (RA) and serologic phenotypes.

METHODS

We investigated smoking cessation and RA risk in the Nurses' Health Study (NHS) (1976-2014) and the NHS II (1989-2015). Smoking exposures and covariates were obtained by biennial questionnaires. Self-reported RA was confirmed by medical record review for American College of Rheumatology/European League Against Rheumatism criteria. Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for RA serologic phenotypes (all, seropositive, seronegative) according to smoking status, intensity, pack-years, and years since cessation.

RESULTS

Among 230,732 women, we identified 1,528 incident cases of RA (63.4% of which were seropositive) during 6,037,151 person-years of follow-up. Compared with never smoking, current smoking increased the risk of all RA (multivariable HR 1.47, 95% CI 1.27-1.72) and seropositive RA (HR 1.67, 95% CI 1.38-2.01) but not seronegative RA (HR 1.20, 95% CI 0.93-1.55). An increasing number of smoking pack-years was associated with an increased trend for the risk of all RA (P < 0.0001) and seropositive RA (P < 0.0001). With increasing duration of smoking cessation, a decreased trend for the risk of all RA was observed (P = 0.009) and seropositive RA (P = 0.002). Compared to recent quitters (<5 years), those who quit ≥30 years ago had an HR of 0.63 (95% CI 0.44-0.90) for seropositive RA. However, a modestly increased risk of RA was still detectable 30 years after quitting smoking (for all RA, HR 1.25 [95% CI 1.02-1.53]; for seropositive RA, HR 1.30 [95% CI 1.01-1.68]; reference, never smoking).

CONCLUSION

These results confirm that smoking is a strong risk factor for developing seropositive RA and demonstrate for the first time that a behavior change of sustained smoking cessation could delay or even prevent seropositive RA.

Association between snus use over time and smoking cessation in Norwegian smokers

BACKGROUND AND AIMS

The effect of snus (Swedish moist snuff) use over time on smoking cessation has not been clearly established. This study aimed to assess whether there is an association between snus use over the life-span and smoking cessation in Norway.

DESIGN AND SETTING

Yearly national cross-sectional surveys (2007-17) among Norwegian adults.

PARTICIPANTS

A total of 5353 ever-daily smokers aged 16-79 years, 61.0% of whom (n = 3268) had quit daily smoking, and 16.9% (n = 903) were ever snus users.

MEASUREMENTS

Retrospective data on smoking and snus use initiation and smoking cessation. Cox proportional hazard models were applied to estimate the association between time from initiation of snus use and quitting smoking.

FINDINGS

There was a significant association between snus use and quitting smoking during the 5 first years after starting using snus (hazard ratio = 1.92, confidence interval = 1.62-2.26), but not thereafter.

CONCLUSION

In Norway, snus use appears to be associated with a higher likelihood of quitting smoking within the first 5 years of initiation of this use.

Association Between Cigarette Smoking and Systemic Lupus Erythematosus: An Updated Multivariate Bayesian Metaanalysis

OBJECTIVE

The association between cigarette smoking and the risk of systemic lupus erythematosus (SLE) remains a matter for debate. Additionally, the effect of the change of smokers' demographics on the risk of development of SLE over time has not been formally addressed. We aimed to examine the association between cigarette smoking and the risk of SLE by performing an updated metaanalysis.

METHODS

A literature search using keywords including "lupus," "smoking," "cigarette," "environmental," "autoimmune," and "connective tissue disease" was performed in computerized databases to identify studies addressing the relationship between cigarette smoking and SLE occurrence. A Bayesian metaanalysis was conducted by computing the log-OR between current and never smokers, and between former and never smokers. The average log-OR (subsequently converted to OR) and their corresponding 95% credible intervals (CrI) were calculated. The effect of publication time, sex, and age of patients with SLE on the effect sizes was examined by multivariate metaregression.

RESULTS

Data aggregation of 12 eligible studies comprising 3234 individuals who developed SLE and 288,336 control subjects revealed a significant association between SLE occurrence and current smoking status (OR 1.54, 95% CrI 1.06-2.25), while only a non-significant trend was demonstrated between SLE occurrence and former smoking status (OR 1.39, 95% CrI 0.95-2.08). Publication time, sex, and the mean age of patients with SLE did not explain the heterogeneity of the effect sizes.

CONCLUSION

Current smoking status is associated with risk of SLE. Sex and age of patients with SLE had no significant effect on the risk of SLE over time.

Occupational exposure to organic dusts and risk of developing rheumatoid arthritis: findings from a Swedish population-based case-control study

Objectives

We estimated the association between occupational exposures to five different organic dusts: wood, animal, paper, textile and flour dust and the risk of developing rheumatoid arthritis (RA).

Methods

This population-based case–control study analysed 12 582 incident cases and 129 335 controls. Participants were identified from national public authority and quality registers. Census data on occupations were collected 1960–2010 and we estimated the exposure to organic dust with the help of job-exposure matrices. We used logistic regression to assess the OR of seropositive or seronegative RA. Estimates were adjusted for the matching variables (sex, county, age and index year), education and occupational silica exposure.

Results

Exposure to animal dust was associated with an increased risk of RA among both men and women. The OR was 1.2 (95% CI=1.1 to 1.4) for seropositive RA and 1.3 (95% CI=1.1 to 1.5) for seronegative RA among ever exposed participants compared with unexposed. The risk increased with duration of exposure for seropositive RA, and participants who had been exposed in five or more censuses had an OR of 1.6 (95% CI=1.1 to 2.2, p for trend=0.003). Exposure to textile dust also generated a significant dose–response relationship for seropositive RA (p for trend=0.014). We detected no association between exposure to wood, paper or flour dust and risk of RA.

Conclusions

Overall, exposure to animal dust and textile dust was associated with an increased risk of developing RA. These observations give further support to the notion that airborne exposures are involved in the aetiology of RA.

Periodontal disease and influence of periodontal treatment on disease activity in patients with rheumatoid arthritis and spondyloarthritis

The aim of this study was to assess the prevalence of periodontal disease and the effect of periodontal treatment in patients with rheumatoid arthritis (RA) and spondyloarthritis (SpA). Forty-four RA patients, thirty SpA patients and thirty-nine healthy volunteers were recruited to the study. Periodontal examination included the approximal plaque index (API), bleeding on probing (BoP), probing depth (PD) and number of teeth. Samples from the deepest periodontal pockets were taken for the detection of Porphyromonas gingivalis DNA with the use of the polymerase chain reaction. All subjects with periodontitis, who completed the study, received periodontal treatment consisting of scaling/root planing and oral hygiene instructions. Disease activity scores, clinical and laboratory parameters were assessed before and 4-6 weeks after periodontal treatment. No significant difference in the prevalence of periodontal disease and the presence of P. gingivalis DNA were found in RA and SpA patients compared to healthy controls. Significantly higher API (80% vs 63%; p = 0.01) and a lower number of teeth (20 vs 25, p = 0.001) were found in RA patients. BoP was significantly elevated in SpA patients (51% vs 33%, p = 0.02). Disease activity measured by the DAS28(CRP) was significantly reduced in RA patients after periodontal treatment (p = 0.002). Clinical and biochemical parameters were not improved in SpA patients. Nonsurgical periodontal treatment had an impact on the decrease in RA activity. Periodontal examination is necessary in patients with RA to detect and treat periodontitis at an early stage.

Body Mass Index and the Risk of Rheumatoid Arthritis: An Updated Dose-Response Meta-Analysis

Background

Extensive studies have been carried out to investigate the association between obesity and the risk of rheumatoid arthritis (RA); however, the results of the current reported original studies remain inconsistent. This study aimed to clarify the relationship between body mass index and rheumatoid arthritis by conducting an updated overall and dose-response meta-analysis.

Methods

The relevant literature was searched using the PubMed and Embase databases (through 20 September 2018) to identify all eligible published studies. Random-effect models and dose-response meta-analyses were used to estimate the pooled risk ratio (RR) with a 95% confidence interval (CI). Subgroup analyses were also conducted based on the characteristics of the participants. Sensitivity analyses and publication bias tests were also performed to explore potential heterogeneity and bias in the meta-analysis.

Results

Sixteen studies that included a total of 406,584 participants were included in the meta-analysis. Compared to participants with normal weight, the pooled RRs of rheumatoid arthritis were 1.12 (95% CI, 1.04-1.20) in overweight and 1.23 (95% CI, 1.09-1.39) in obese participants. There was evidence of a nonlinear relationship between body mass index (BMI) and RA (P  for nonlinearity less than 0.001 in the overall meta-analysis, P for nonlinearity=0.025 in the case-control studies, P for nonlinearity=0.0029 in the cohort studies). No significant heterogeneity was found among studies (I²=10.9% for overweight and I²=45.5% for obesity).

Conclusion

The overall and dose-response meta-analysis showed that increased BMI was associated with an increased risk for rheumatoid arthritis, which might present a prevention strategy for the prevention or control of rheumatoid arthritis. The nonlinear relationship between BMI and RA might present a personal prevention strategy for RA.

Potential of Lifestyle Changes for Reducing the Risk of Developing Rheumatoid Arthritis: Is an Ounce of Prevention Worth a Pound of Cure?

PURPOSE

Lifestyle may be important in the development of rheumatoid arthritis (RA). Therefore, changing behaviors may delay or even prevent RA onset. This article reviews the evidence basis for the associations of lifestyle factors with RA risk and considers future directions for possible interventions to reduce RA risk.

METHODS

The literature was reviewed for cross-sectional studies, case-control studies, cohort studies, and clinical trials investigating potentially modifiable lifestyle factors and RA risk or surrogate outcomes on the path toward development such as RA-related autoimmunity or inflammatory arthritis. The evidence related to cigarette smoking, excess weight, dietary intake, physical activity, and dental health for RA risk were summarized.

FINDINGS

Cigarette smoking has the strongest evidence base as a modifiable lifestyle behavior for increased seropositive RA risk. Smoking may increase seropositive RA risk through gene-environment interactions, increasing inflammation and citrullination locally in pulmonary/oral mucosa or systemically, thereby inducing RA-related autoimmunity. Prolonged smoking cessation may reduce seropositive RA risk. Evidence suggests that excess weight can increase RA risk, although this effect may differ according to sex, serologic status, and age at RA onset. TDietary intake may also affect RA risk: overall healthier patterns, high fish/omega-3 polyunsaturated fatty acid consumption, and moderate alcohol intake may reduce RA risk, whereas caffeine and sugar-sweetened soda consumption might increase RA risk. The impact of physical activity is less clear, but high levels may reduce RA risk. Periodontal disease might induce citrullination and RA-related autoimmunity, but the effect of dental hygiene behaviors on RA risk is unclear. Although the effect size estimates for these lifestyle factors on RA risk are generally modest, there may be relatively large public health benefits for targeted interventions given the high prevalence of these unhealthy behaviors. With the exception of smoking cessation, the impact of behavior change of these lifestyle factors on subsequent RA risk has not been established. Nearly all of the evidence for lifestyle factors and RA risk were derived from observational studies.

IMPLICATIONS

There are many potentially modifiable lifestyle factors that may affect RA risk. Improving health behaviors could have large public health benefits for RA risk given the high prevalence of many of the RA risk-related lifestyle factors. However, future research is needed to establish the effects of lifestyle changes on RA risk or surrogate outcomes such as RA-related autoimmunity or inflammatory arthritis.

Impact of smoking on thyroid gland: dose-related effect of urinary cotinine levels on thyroid function and thyroid autoimmunity

Cigarette smoking is believed to affect thyroid function and autoimmune thyroid disease. However, there is little information to analyze their association using objective biomarkers. The aim of this study was to investigate the dose-related effect of smoking on thyroid hormones and thyroid peroxidase antibody (TPO Ab) using urinary cotinine levels and a population-based cohort. The present study used the thyroid hormone and urinary cotinine dataset from sixth Korean National Health and Nutrition Examination Survey in 2014 and 2015, and a total of 4249 participants were included. Dose-response relationships between thyroid hormone (free T4, TSH, and TPO Ab) and urinary cotinine levels were estimated using ANCOVA after adjustment for all variables (age, height, weight, alcohol, exercise, and log- transformed iodine in urine). Urinary cotinine level was negatively correlated with TSH. The estimated coefficients were −0.0711 in males and −0.0941 in females (p < 0.0001). TPO Ab titer was positively correlated with cotinine levels in males (p < 0.0001). Our findings indicated a significant dose-related effect of urinary cotinine level on thyroid function, and thyroid autoimmunity.

Risk factor assessment of rheumatoid arthritis in North Kerala

OBJECTIVE

Rheumatoid arthritis (RA) is a multifactorial disease; it leads to disabling and painful chronic inflammatory arthritis. Its onset may be delayed or even prevented by modifying the risk factors involved. Many genetic, epigenetic, and environmental factors are implicated in the pathogenesis of RA. The objectives of this case-control study were to assess various risk factors in our population and to compare the same with age- and sex-matched controls.

METHODS

We studied 118 cases with RA diagnosed using the EULAR criteria. In total, 581 age- and sex-matched controls were selected. Each individual was administered a separate questionnaire regarding their risk factors (known risk factors were studied). The implicated dietary factors were incorporated in a food frequency questionnaire (FFQ) and administered to both cases and controls. Comparison was made between those who consume an item at a particular frequency, who consume less, and who consume nothing at all. Among those who consume, each group was re-compared. Statistical analysis was conducted using Statistical Package for Social Sciences (IBM Corp.; Armonk, NY, USA).

RESULTS

There was significant relationship for family history, periodontitis, history of chikungunya, and sun exposure (p<0.05). Association with various food items was studied using the FFQ, but the relationship was inconsistent, probably due to consumption of modified diet by the persons with RA. Also, a majority of cases were females and nonsmokers for assessing an association with smoking habits.

CONCLUSION

In our population, previous infections (e.g., chikungunya and poor oral hygiene with periodontitis) were the prominently observed risk factors. Also, smoking was less common among women, and probably contributed less, as majority of cases were females. For dietary pattern association, a prospective cohort study may be needed.

Smoking reduces the efficacy of belimumab in mucocutaneous lupus

OBJECTIVES

Recently, we demonstrated a negative impact of smoking on belimumab efficacy in patients with systemic lupus erythematosus (SLE). Here, we particularly investigated clinical effects of belimumab and a potential impact of smoking in mucocutaneous and articular SLE.

METHODS

We surveyed 62 SLE patients treated between 2011 and 2017. Evaluation included the mucocutaneous descriptors of SLEDAI-2K (rash, alopecia, mucosal ulcers; mcSLEDAI-2K), CLASI, the arthritis SLEDAI-2K descriptor (arSLEDAI-2K) and the 28-joint count.

RESULTS

mcSLEDAI-2K and CLASI activity decreased from baseline to month 6 and 12 (P < 0.001 for all). No worsening in CLASI damage was observed. Current or previous smokers displayed a higher probability of unchanged/worsened mcSLEDAI-2K compared to never smokers (OR: 6.4; 95% CI: 1.5-27.4; P = 0.012), also after adjustment for antimalarial agents. arSLEDAI-2K scores had decreased at month 6 (P < 0.001) and 12 (P < 0.001). Likewise, tender and swollen 28-joint counts had improved at month 6 (P = 0.010 and P < 0.001, respectively) and 12 (P = 0.001 for both). We observed no impact of smoking on belimumab efficacy in articular SLE.

CONCLUSION

We observed a negative impact of smoking on the efficacy of belimumab in mucocutaneous SLE. In contrast, no impact of smoking on belimumab efficacy was seen in patients with articular manifestations.

Smoking-induced aggravation of experimental arthritis is dependent of aryl hydrocarbon receptor activation in Th17 cells

BACKGROUND

Epidemiologic studies have highlighted the association of environmental factors with the development and progression of autoimmune and chronic inflammatory diseases. Among the environmental factors, smoking has been associated with increased susceptibility and poor prognosis in rheumatoid arthritis (RA). However, the immune and molecular mechanism of smoking-induced arthritis aggravation remains unclear. The transcription factor aryl hydrocarbon receptor (AHR) regulates the generation of Th17 cells, CD4 T cells linked the development of autoimmune diseases. AHR is activated by organic compounds including polycyclic aromatic hydrocarbons (PAHs), which are environmental pollutants that are also present in cigarette smoke. In this study, we investigated the role of AHR activation in the aggravation of experiment arthritis induced by exposure to cigarette smoke.

METHODS

Mice were exposed to cigarette smoke during the developmental phase of antigen-induced arthritis and collagen-induced arthritis to evaluate the effects of smoking on disease development. Aggravation of articular inflammation was assessed by measuring neutrophil migration to the joints, increase in articular hyperalgesia and changes in the frequencies of Th17 cells. In vitro studies were performed to evaluate the direct effects of cigarette smoke and PAH on Th17 differentiation. We also used mice genetically deficient for AHR (Ahr KO) and IL-17Ra (Il17ra KO) to determine the in vivo mechanism of smoking-induced arthritis aggravation.

RESULTS

We found that smoking induces arthritis aggravation and increase in the frequencies of Th17 cells. The absence of IL-17 signaling (Il17ra KO) conferred protection to smoking-induced arthritis aggravation. Moreover, in vitro experiments showed that cigarette smoke can directly increase Th17 differentiation of T cells by inducing AHR activation. Indeed, Ahr KO mice were protected from cigarette smoke-induced arthritis aggravation and did not display increase in TH17 frequencies, suggesting that AHR activation is an important mechanism for cigarette smoke effects on arthritis. Finally, we demonstrate that PAHs are also able to induce arthritis aggravation.

CONCLUSIONS

Our data demonstrate that the disease-exacerbating effects of cigarette smoking are AHR dependent and environmental pollutants with AHR agonist activity can induce arthritis aggravation by directly enhancing Th17 cell development.

Cigarette smoking and the pathogenesis of systemic lupus erythematosus

INTRODUCTION

Systemic lupus erythematosus (SLE) is a multi-system inflammatory autoimmune disease of incompletely understood etiology. It is thought that environmental exposures 'trigger' or accelerate the disease in genetically-predisposed individuals. Areas covered: Substantial epidemiological evidence exists to support the association between cigarette smoking and the risk of incident SLE. Recent evidence points to current smoking as the specific risk factor, with decreasing risk 5 years after smoking cessation, and the greatest risk for disease characterized by the presence of SLE-specific autoantibodies. Research has begun to search for possible explanations for the temporal nature of the relationship between current smoking and autoantibody positive-SLE. Here we review potential biologic mechanisms linking smoking and SLE risk, including effects upon T and B cells, inflammatory cytokines, oxidative stress, and the formation of short-lived DNA adducts. Expert commentary: The directions for future research in this field include studies of gene-environment interactions, epigenetics, metabolomics and putative biologic mechanisms.

Smoking under hypoxic conditions: a potent environmental risk factor for inflammatory and autoimmune diseases

Autoimmune disease management presents a significant challenge to medical science. Environmental factors potentially increase the risk of developing inflammatory and autoimmune diseases, such as multiple sclerosis, rheumatoid arthritis, and lupus. Among various environmental stresses, cigarette smoke and hypoxia have both been reported to lead to an enhanced risk of inflammatory and autoimmune diseases.In this review, we shed light on all reported mechanisms whereby cigarette smoke and a hypoxic environment can induce inflammatory and autoimmune diseases and discuss how hypoxic conditions influence the cigarette smoke-induced threat of inflammatory and autoimmune disease development.Cigarette smoke and hypoxia both lead to increased oxidative stress and production of reactive oxygen species and other free radicals, which have various effects including the generation of autoreactive pro-inflammatory T cells and autoantibodies, reductions in T regulatory (Treg) cell activity, and enhanced expression of pro-inflammatory mediators [e.g., interleukin-6 (IL-6), interleukin-4 (IL-4) and interleukin-8 (IL-8)]. Accordingly, smoking and hypoxic environments may synergistically act as potent environmental risk factors for inflammatory and autoimmune diseases. To our knowledge, no studies have reported the direct association of cigarette smoke and hypoxic environments with the risk of developing inflammatory and autoimmune diseases.Future studies exploring the risk of autoimmune disease development in smokers at high altitudes, particularly military personnel and mountaineers who are not acclimatized to high-altitude regions, are required to obtain a better understanding of disease risk as well as its management.

Cigarette smoking and the risk of systemic lupus erythematosus, overall and by anti-double stranded DNA antibody subtype, in the Nurses' Health Study cohorts

OBJECTIVES

Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease, subtyped according to clinical manifestations and autoantibodies. Evidence concerning cigarette smoking and SLE risk has been conflicting. We investigated smoking and SLE risk, overall and by anti-double stranded DNA (dsDNA) presence, in two prospective cohort studies.

METHODS

The Nurses' Health Study (NHS) enrolled 121 701 US female nurses in 1976; Nurses' Health Study II (NHSII) enrolled 116 430 in 1989. Lifestyle, environmental and medical data were collected through biennial questionnaires. Incident SLE was confirmed by medical record review. Cox regression models estimated HRs of SLE, overall and by dsDNA subtype, in association with time-varying smoking status and cumulative smoking pack-years through the 2-year cycle prior to diagnosis, controlling for potential confounders.

RESULTS

Among 286 SLE cases identified (159 in NHS (1978-2012) and 127 in NHSII (1991-2013)), mean age was 49.2 (10.3) years and 42% were dsDNA+ at SLE diagnosis. At baseline, 45% of women had ever smoked, 51% of whom currently smoked. Compared with never smokers, current smokers had increased dsDNA+ SLE risk (HR 1.86 (1.14-3.04)), whereas past smokers did not (HR 1.31 (0.85-2.00)). Women who smoked >10 pack-years (vs never) had an elevated dsDNA+ SLE risk (HR 1.60(95% CI 1.04 to 2.45)) compared with never smokers. No associations were observed between smoking status or pack-years and overall SLE or dsDNA- SLE.

CONCLUSION

Strong and specific associations of current smoking and >10 pack-years of smoking with dsDNA+ SLE were observed. This novel finding suggests smoking is involved in dsDNA+ SLE pathogenesis.

Smoking and susceptibility to rheumatoid arthritis in a Swedish population-based case-control study

Smoking is one of the most established risk factors for rheumatoid arthritis (RA). The aim of this study was to estimate how age at smoking debut, smoking cessation, duration, intensity, and cumulative dose of smoking influence the risk of developing anti-citrullinated peptide antibodies (ACPA) positive and ACPA negative RA. The present report is based on a Swedish population-based, case–control study with incident cases of RA (3655 cases, 5883 matched controls). Using logistic regression models, subjects with different smoking habits were compared regarding risk of developing the two variants of RA, by calculating odds ratios (OR) with 95% confidence intervals (CI). Smoking increased the risk of developing both ACPA positive (OR 1.9, 95% CI 1.7–2.1) and ACPA negative RA (OR 1.3, 95% CI 1.2–1.5). For both subsets of RA, there seemed to be a threshold (~ 2.5 pack years for ACPA positive RA and ~ 5 pack years for ACPA negative RA) below which no association between smoking and RA occurred. A dose–response association was observed between cumulative dose of smoking and risk of developing ACPA positive RA (p value for trend < 0.0001). Duration of smoking had a higher influence on the association between smoking and RA than did intensity of smoking. For both subsets of RA, the detrimental effect of smoking decreased after smoking cessation. Twenty years after smoking cessation, there was no longer an association between smoking and risk of ACPA negative RA, whereas the association between smoking and ACPA positive RA risk persisted and was dependent on the cumulative dose of smoking. Smoking increases the risk of both subsets of RA with a more pronounced influence on the risk of ACPA positive RA. Preventive measures in order to reduce smoking are essential and may result in a decline in RA incidence.

The association between omega-3 fatty acid biomarkers and inflammatory arthritis in an anti-citrullinated protein antibody positive population

Objectives

Higher circulating omega-3 fatty acids (n-3 FAs) are associated with a lower prevalence of anti-CCP antibodies and RF in subjects without RA. We examined whether, in anti-CCP+ subjects, n-3 FAs also play a role in development of inflammatory arthritis (IA).

Methods

At Colorado-based health fairs from 2008 to 2014, participants without a previous diagnosis of RA who were anti-CCP3+ (n = 47) were recruited into a follow-up study; symptom assessments and joint examinations were conducted every 6 months for the determination of IA. We measured n-3 FAs as a percentage of total lipids in red blood cell membranes (n-3 FA%) at each visit.

Results

We detected IA in 10 anti-CCP3+ subjects (21%) at the baseline visit. Increased total n-3 FA% in red blood cell membranes [odds ratio (OR) = 0.09, 95% CI: 0.01, 0.76], specifically docosapentaenoic acid (OR = 0.16, 95% CI: 0.03, 0.83) and docosahexaenoic acid (OR = 0.23, 95% CI: 0.06, 0.86), was associated with a lower odds of IA at the baseline visit, adjusting for n-3 FA supplement use, current smoking, RF+, elevated CRP+ and shared epitope. We followed 35 of the anti-CCP3+ subjects who were IA negative at baseline and detected 14 incident IA cases over an average of 2.56 years of follow-up. In a time-varying survival analysis, increasing docosapentaenoic acid significantly decreased risk of incident IA (hazard ratio = 0.52, 95% CI: 0.27, 0.98), adjusting for age at baseline, n-3 FA supplement use, RF+, CRP+ and shared epitope.

Conclusion

n-3 FAs may potentially lower the risk of transition from anti-CCP positivity to IA, an observation that warrants further investigation.

Risk Factors Associated with Juvenile Idiopathic Arthritis: Exposure to Cigarette Smoke and Air Pollution from Pregnancy to Disease Diagnosis

Objective.

To evaluate exposure to environmental factors inhaled during pregnancy and after birth until juvenile idiopathic arthritis (JIA) diagnosis among residents of a large city.

Methods.

This is an exploratory case-control study that consists of 66 patients with JIA and 124 healthy controls matched by age and sex, living in the São Paulo, Brazil, metropolitan area until JIA diagnosis, and whose mothers had resided in this region during pregnancy. A structured and reliable questionnaire (κ index for test-retest was 0.80) assessed demographic data, gestational and perinatal-related factors, and exposure to inhalable environmental elements during pregnancy and after birth (occupational exposure to inhalable particles and/or volatile vapor, exposure to cigarette smoke, and the presence of industrial activities or gas stations near the home, work, daycare, or school). Tropospheric pollutants included particulate matter (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and carbon monoxide (CO).

Results.

During pregnancy, intrauterine cigarette smoke exposure (OR 3.43, 95% CI 1.45–8.12, p = 0.005) and maternal occupational exposure (OR 13.69, 95% CI 4.4–42.3, p < 0.001) were significant independent risk factors for JIA diagnosis. In contrast, maternal employment (OR 0.06, 95% CI 0.02–0.2, p < 0.001) and ideal maternal weight gain (OR 0.36, 95% CI 0.2–0.8, p = 0.017) presented negative associations. Secondhand smoke exposure from birth to JIA diagnosis (OR 3.6, 95% CI 1.8–7.3, p < 0.001) and exposure to O3during the second year of life (OR 2.76, 95% CI 1.20–6.37, p = 0.017) were independent and significant risk factors for the pathogenesis of JIA.

Conclusion.

In our study, cigarette smoke exposure (intrauterine and after birth), exposure to O3in the second year of life, and maternal occupational exposure were identified as potential risk factors for JIA, warranting further study.

Managing Cardiovascular Disease Risk in Rheumatoid Arthritis: Clinical Updates and Three Strategic Approaches

ᅟ: The increase in cardiovascular disease (CVD) risk in rheumatoid arthritis (RA) is well known; however, appropriate management of this elevated risk in rheumatology clinics is less clear.

PURPOSE OF REVIEW

By critically reviewing literature published within the past 5 years, we aim to clarify current knowledge and gaps regarding CVD risk management in RA.

RECENT FINDINGS

We examine recent guidelines, recommendations, and evidence and discuss three approaches: (1) RA-specific management including treat-to-target and medication management, (2) assessment of comprehensive individual risk, and (3) targeting traditional CVD risk factors (hypertension, smoking, hyperlipidemia, diabetes, obesity, and physical inactivity) at a population level. Considering that 75% of US RA visits occur in specialty clinics, further research is needed regarding evidence-based strategies to manage and reduce CVD risk in RA. This review highlights clinical updates including US cardiology and international professional society guidelines, successful evidence-based population approaches from primary care, and novel opportunities in rheumatology care to reduce CVD risk in RA.

Influence of Cigarette Smoking on Rheumatoid Arthritis Risk in the Han Chinese Population

OBJECTIVES

Cigarette smoking has been shown in European populations to be associated with rheumatoid arthritis (RA) susceptibility. This study aims to examine the association of smoking with RA in the Han Chinese population.

METHODS

718 Han Chinese RA patients and 404 healthy controls were studied. The associations of cigarette smoking (current, former or ever vs. never smokers, and pack-years of exposure) with RA, anti-cyclic citrullinated peptide antibody (ACPA) positive RA, IgM rheumatoid factor (RF) positive RA, and baseline radiographic erosions (modified van der Heijde-Sharp scores) were assessed. The interaction between smoking and the HLA-DRB1 shared epitope (SE) in RA was also examined.

RESULTS

In this study, 11 (1.53%) cases and 6 (1.49%) controls were former smokers (p = 0.95), while 95 (13.23%) cases and 48 (11.88%) controls were current smokers (p = 0.52). Trends toward associations between smoking status (ever vs. never) with RA-overall (p = 0.15, OR = 1.44), ACPA-positive RA (p = 0.24, OR = 1.37), RF-positive RA (p = 0.14, OR = 1.46), or the presence of radiographic erosions (p = 0.66, OR = 1.28) were observed although individually here were not statistically significant. There was no evidence of statistical interaction between smoking status (ever vs. never) and SE for all RA, ACPA-positive RA, ACPA-negative RA, RF-positive RA, RF-negative RA (p = 0.37, 0.50, 0.24, 0.26, and 0.81 respectively), and the 95% CI for the attributable proportion for all interactions included 0.

CONCLUSION

This is the first study to examine the association of cigarette smoking with RA in the Han Chinese population. This study shows a trend toward an interaction between smoking and SE carriage influencing the risk of RA, though findings were not statistically significant. It is possible that in the presence of universal exposure to heavy air pollution the effect of smoking on RA risk may be obscured.

A case-control study of rheumatoid arthritis revealed abdominal obesity and environmental risk factor interactions in northern China

BACKGROUND

The aim of this study was to evaluate new and previously hypothesized environmental risk factors and their interaction with rheumatoid arthritis (RA).

METHODS

Four hundred patients recently diagnosed with RA and 400 controls frequency-matched by gender and birth year using Propensity Score Matching (PSM) were selected from northern China. Investigation was performed using self-reported data from interviewer-administered surveys. Associations between exposure variables and risk of RA were evaluated using multifactor non-conditional logistic regression.

RESULTS

It showed that damp localities, draft indoor, abdominal obesity (AO), and family history of RA among first-degree relatives were independent risk factors and drinking of milk was independent protective factors for RA. Besides these risk factors, in women, infrequent delivery times, early age at menopause, and late age at menarche were also independent risk factors for RA. Both the additive model and the multiplication model suggested that there was an interaction relationship between AO and damp localities (p < .001), and only the additive model suggested that there was interaction relationship between AO and no milk drinking (p < .001) in our study population. In women, there was interaction relationship between AO and damp localities (p < .001) and between AO and age at menopause (p < .001).

CONCLUSIONS

In northern China, damp localities, draft indoor, AO, family history of RA among first-degree relatives, and no milk drinking may be important risk factors of RA patients.

Incidence of Chronic Persistent Rheumatoid Arthritis and the Impact of Smoking: A Historical Twin Cohort Study

OBJECTIVE

To assess the incidence of chronic persistent rheumatoid arthritis (RA) in a population-based cohort of twins and to determine the impact of smoking.

METHODS

In a historical cohort study on twins born in 1920 to 1982, we identified 157 cases of RA among 45,280 responders (response rate 80%). Information on smoking was obtained by questionnaire and interview. A mixed-effects Poisson regression model was used to estimate incidence rate ratios with age, sex, smoking duration, and smoking intensity as covariates. We used the SplitLexis procedure in the Epi R package to study a possible effect of period or cohort in addition to age on the variation of the incidence.

RESULTS

The annual incidence of chronic persistent RA was 18.8 per 100,000 person-years, ages 15-73 years (females 25.2, males 12.0), increasing with age to a maximum at age 60 years in females and age 70 years in males. The incidence rate ratio among ever-smoking patients was 1.96 (95% confidence interval [95% CI] 1.43-3.76), 1.93 (95% CI 1.00-3.7) after 30 pack-years, and 1.034 (P < 0.001) per year of smoking, implying a doubling of risk after 20 years regardless of sex and smoking intensity. We did not detect significant period or cohort effects.

CONCLUSION

The incidence of chronic persistent RA is lower than the incidence figures reported in inception cohorts. Smoking duration, but not intensity, doubled the risk of RA after 20 years of smoking in both sexes.

Physical workload is associated with increased risk of rheumatoid arthritis: results from a Swedish population-based case-control study

Objectives

This study investigated: (1) the association of physical workload (PW) and risk of rheumatoid arthritis (RA); (2) the potential interactions between PW and the genes in the human leucocyte antigen (HLA) region.

Methods

A population-based case–control study involving incident cases of RA (3150 cases and 5130 controls) was performed using data from the Swedish Epidemiological Investigation of Rheumatoid Arthritis. Information on 7 types of self-reported PW exposure and HLA-DRB1 genotypes of cases and controls were gathered. Anticitrullinated protein antibody (ACPA) status of cases was identified. For each PW exposures, exposed participants were compared with unexposed participants. ORs with 95% CIs of RA (overall), ACPA-positive RA and ACPA-negative RA associated with different PWs were estimated using logistic regression. HLA-PW interactions were estimated using the principle of departure from additivity of effects by calculating attributable proportion (AP) due to interaction.

Results

ORs of developing RA associated with 6 various PW exposures ranging from 1.3 (95% CI 1.1 to 1.4) to 1.8 (95% CI 1.6 to 2.0) were observed. Exposure to more types of PW was associated with increasing risk for RA (p<0.0001). No major difference in the ORs between ACPA-positive and ACPA-negative RA was found. For some exposures, we found evidence of interactions between PW and the HLA-DRB1 shared epitope genes, regarding risk of ACPA-positive RA (AP: from 0.3 (95% CI 0.1 to 0.5) to 0.4 (95% CI 0.2 to 0.6)).

Conclusions

PW is associated with the risk of ACPA-positive and ACPA-negative RA. Interactions between PW and the HLA-DRB1 shared epitope were found in ACPA-positive RA.

Immunoglobulin (Ig)G1 and IgG4 anti-cyclic citrullinated peptide (CCP) associate with shared epitope, whereas IgG2 anti-CCP associates with smoking in patients with recent-onset rheumatoid arthritis (the Swedish TIRA project)

Given the possible importance of anti-citrullinated peptide/protein antibodies (ACPA) for initiation and progression of rheumatoid arthritis (RA), extended knowledge about the different isotypes and subclasses is important. In the present study, we analysed the immunoglobulin (Ig)G subclasses regarding reactivity against cyclic citrullinated peptides (anti-CCP) among 504 clinically well-characterized patients with recent-onset RA in relation to smoking habits, shared epitope (SE) status and IgA and pan-IgG anti-CCP antibodies. All patients, regardless of pan-IgG anti-CCP status, were analysed for IgG1-4 CCP reactivity. Sixty-nine per cent were positive in any IgG anti-CCP subclass, and of these 67% tested positive regarding IgG1, 35% IgG2, 32% IgG3, and 59% IgG4 anti-CCP. Among ever-smokers the percentages of IgG2 anti-CCP (P = 0·01) and IgA anti-CCP (P = 0·002)-positive cases were significantly higher compared to never-smokers. A positive IgG anti-CCP subclass -negative cases. Combining SE and smoking data revealed that IgG1 and IgG4 anti-CCP were the IgG anti-CCP isotypes associated with expression of SE, although the lower number of patients positive for IgG2 or IgG3 anti-CCP could, however, have influenced the results. High levels of IgG2 anti-CCP were shown to correlate with expression of the 'non-SE' allele human leucocyte antigen (HLA)-DRB1*15. In conclusion, in this study we describe different risk factor characteristics across the IgG anti-CCP subclasses, where IgG2 appears similar to IgA anti-CCP regarding the predominant association with smoking, while IgG1 and IgG4 related more distinctly to the carriage of SE genes.

Serum antibody levels against Porphyromonas gingivalis in patients with and without rheumatoid arthritis - a systematic review and meta-analysis

OBJECTIVES

Since the peptidyl arginine deiminase of Porphyromonas gingivalis is able to citrullinate peptides and proteins, various studies have suggested the species as a possible link between periodontal disease (PD) and rheumatoid arthritis (RA). This systematic review including meta-analysis was aimed to evaluate whether differences in terms of antibody titers against P. gingivalis exist between RA patients and systemically healthy individuals with and without PD.

MATERIALS AND METHODS

The following focused question was addressed: Are the antibody titers against P. gingivalis of RA patients different from systemically healthy individuals with and without PD? A systematic data search was conducted in MEDLINE and EMBASE. The collected data underwent a meta-analysis to detect statistically significant differences in terms of antibody levels between the groups.

RESULTS

From 114 articles found by the search 13 articles met the inclusion criteria and provided data suitable for meta-analysis. After analyzing various levels of confinement the meta-analysis revealed a statistically significant higher antibody titer against P. gingivalis in patients suffering from RA in comparison with systemically and periodontally healthy controls (p < 0.01) and systemically healthy patients with PD (p < 0.01).

CONCLUSION

The present findings indicate that RA is often accompanied by the presence of an immune response against P. gingivalis.

CLINICAL RELEVANCE

The significantly higher antibody response to P. gingivalis in comparison to systemically healthy individuals supports the link between PD and RA by P. gingivalis. Screening of the regularly taken blood samples of RA patients for P. gingivalis antibodies may help to sensitize rheumatologists and RA patients for improving periodontal health.

Cigarette smoking and autoimmune disease: what can we learn from epidemiology?

Cigarette smoking has been causally linked to the development of multiple autoimmune diseases, including rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, Graves' hyperthyroidism, and primary biliary cirrhosis, among others. We review the known biologic effects of cigarette smoke, in particular its actions on the immune system, and the epidemiologic evidence associating smoking with increased risk of each of these autoimmune diseases. Interactions between cigarette smoking and genetic and immunologic factors, such as the human leukocyte antigen (HLA)shared epitope, rheumatoid factor, anti-cyclic citrullinated peptide antibodies, and anti-double stranded DNA antibodies, may point to mechanisms in disease pathogenesis.