Smoking, gender and rheumatoid arthritis–epidemiological clues to etiology

Tailoring Rheumatoid Arthritis Treatment through a Sex and Gender Lens

Rheumatoid arthritis (RA) occurs more frequently in women than in men, and the studies that have addressed clinical and prognostic differences between the sexes are scarce and have contradictory results and methodological problems. The present work aims to evaluate sex- and gender-related differences in the clinical expression and prognosis of RA as well as on the impact on psychosocial variables, coping behavior, and healthcare use and access. By identifying between sex differences and gender-related outcomes in RA, it may be possible to design tailored therapeutic strategies that consider the differences and unmet needs. Being that sex, together with age, is the most relevant biomarker and health determinant, a so-called personalized medicine approach to RA must include clear guidance on what to do in case of differences.

Male rheumatoid arthritis patients at substantially higher risk for cardiovascular mortality in comparison to women

BACKGROUND

Patients with rheumatoid arthritis (RA) are at an increased risk for developing cardiovascular diseases. While advice regarding cardiovascular risk screening and management in RA patients has been incorporated in several guidelines in recent years, its implementation and adherence is still poor.

OBJECTIVES

To assess the cardiovascular disease risk in new diagnosed RA patients and evaluate whether advice to initiate preventive medical treatment of high risk patients was followed.

METHODS

All patients with a recent diagnosis of RA, aged 40-70 years, were screened between May 2019 and December 2022 for cardiovascular diseases and risk factors within the first year after diagnosis at the outpatient rheumatology clinic, as part of standard care. Screening included a physical examination with blood pressure measurement, and laboratory tests with lipid profile tests. All patients and their general practitioner (GP) received an overview with their cardiovascular risk profile and a calculated 10-year cardiovascular mortality risk. Cardiovascular risk was defined as low (<1%), intermediate (1-5%), high (5-10%) and very high (>10%). The national pharmacy network was consulted to check whether or not patients started preventive medication after screening.

RESULTS

A total of 125 RA patients was included in this study. The mean age was 56 years and 78% was female. Median RA disease duration at screening was 6 months. Six patients (5%) indicated to have been screened before, and used antihypertensive medication. During screening, hypertension was found in 57% of male patients and 43% of female patients and dyslipidemia was found in 36% in male and 32% in female patients. 46% of male patients and 21% of female patients currently smoked. A high or very high 10-year cardiovascular mortality risk was found in 50% of male patients, but in only 4% of female patients. Only 26% of (very) high risk patients started antihypertensive or statin medication after screening.

CONCLUSIONS

An increased cardiovascular disease risk is often present in newly diagnosed RA patients, especially male patients, with a large proportion having undiagnosed and untreated hypertension and hypercholesterolemia. Even with structural screening and informing of the patients and GPs, treatment of cardiovascular risk factors in high risk patients remains insufficient. CV risk screening needs to be part of standard care for RA patients, with clear agreement on the responsibilities between primary and secondary care. Awareness of the importance of CVD risk screening needs to improve among both RA patients themselves and the GPs to ultimately reduce the cardiovascular burden of our patients. Obviously, a better collaboration between GPs and rheumatologists is urgently needed to lower the cardiovascular burden of our patients.

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.

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.

Zinc and Cadmium in the Aetiology and Pathogenesis of Osteoarthritis and Rheumatoid Arthritis

Osteoarthritis (OA) and rheumatoid arthritis (RA) are inflammatory articular conditions with different aetiology, but both result in joint damage. The nutritionally essential metal zinc (Zn²⁺) and the non-essential metal cadmium (Cd²⁺) have roles in these arthritic diseases as effectors of the immune system, inflammation, and metabolism. Despite both metal ions being redox-inert in biology, they affect the redox balance. It has been known for decades that zinc decreases in the blood of RA patients. It is largely unknown, however, whether this change is only a manifestation of an acute phase response in inflammation or relates to altered availability of zinc in tissues and consequently requires changes of zinc in the diet. As a cofactor in over 3000 human proteins and as a signaling ion, zinc affects many pathways relevant for arthritic disease. How it affects the diseases is not just a question of zinc status, but also an issue of mutations in the many proteins that maintain cellular zinc homoeostasis, such as zinc transporters of the ZIP (Zrt-/Irt-like protein) and ZnT families and metallothioneins, and the multiple pathways that change the expression of these proteins. Cadmium interferes with zinc's functions and there is increased uptake under zinc deficiency. Remarkably, cadmium exposure through inhalation is now recognized in the activation of macrophages to a pro-inflammatory state and suggested as a trigger of a specific form of nodular RA. Here, we discuss how these metal ions participate in the genetic, metabolic, and environmental factors that lead to joint destruction. We conclude that both metal ions should be monitored routinely in arthritic disease and that there is untapped potential for prognosis and treatment.

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.

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.

The Clinical Application of Anti-CCP in Rheumatoid Arthritis and Other Rheumatic Diseases

Rheumatoid arthritis (RA) is a common rheumatic disease in Caucasians and in other ethnic groups. Diagnosis is mainly based on clinical features. Before 1998, the only serological laboratory test that could contribute to the diagnosis was that for rheumatoid factor (RF). The disease activity markers for the evaluation of clinical symptoms or treatment outcome were the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). As a matter of fact, the diagnosis of early RA is quite impossible, as the clinical criteria are insufficient at the beginning stage of the disease. In 1998, Schelleken reported that a high percentage of RA patients had a specific antibody that could interact with a synthetic peptide which contained the amino acid citrulline. The high specificity (98%) for RA of this new serological marker, anti-cyclic citrullinated antibody (anti-CCP antibody), can be detected early in RA, before the typical clinical features appear. The presence or absence of this antibody can easily distinguish other rheumatic diseases from RA. Additionally, the titer of anti-CCP can be used to predict the prognosis and treatment outcome after DMARDs or biological therapy. Therefore, with improvement of sensitivity, the anti-CCP antibody will be widely used as a routine laboratory test in the clinical practice for RA.

The Autoimmune Ecology

Autoimmune diseases (ADs) represent a heterogeneous group of disorders that affect specific target organs or multiple organ systems. These conditions share common immunopathogenic mechanisms (i.e., the autoimmune tautology), which explain the clinical similarities they have among them as well as their familial clustering (i.e., coaggregation). As part of the autoimmune tautology, the influence of environmental exposure on the risk of developing ADs is paramount (i.e., the autoimmune ecology). In fact, environment, more than genetics, shapes immune system. Autoimmune ecology is akin to exposome, that is all the exposures - internal and external - across the lifespan, interacting with hereditary factors (both genetics and epigenetics) to favor or protect against autoimmunity and its outcomes. Herein, we provide an overview of the autoimmune ecology, focusing on the immune response to environmental agents in general, and microbiota, cigarette smoking, alcohol and coffee consumption, socioeconomic status (SES), gender and sex hormones, vitamin D, organic solvents, and vaccines in particular. Inclusion of the autoimmune ecology in disease etiology and health will improve the way personalized medicine is currently conceived and applied.

Tobacco and other environmental risk factors in rheumatoid arthritis

Many environmental factors have been associated with an increased risk of developing Rheumatoid Arthritis (RA), but so far smoking is the only environmental risk factor that has been extensively studied and widely accepted. Smoking is associated with an increased risk of developing seropositive RA (RF and/or ACPA). Recent studies show that tobacco smoking can influence disease phenotype, with the development of more aggressive disease and greater joint damage; but other studies show contradictory results. Recent data suggests that response to antirheumatic therapy in RA is worse in smokers. In this article we review different environmental factors that have been associated with an increased risk of developing RA, with a special interest in tobacco smoking.

Modifiable risk factors for RA: prevention, better than cure?

Objective. To perform a meta-synthesis of the evidence for modifiable lifestyle risk factors for inflammatory polyarthritis (IP) and RA.

Methods. We performed a MEDLINE literature search. Case–control and cohort studies and systematic reviews published from 1948 through February 2011 and studying modifiable risk factors for RA were retrieved. The main outcome measure was diagnosis of RA according to the standard criteria.

Results. Smoking contributes up to 25% of the population burden of RA. The risk is dose related, stronger in males and especially strong for anti-citrullinated peptide antibody positive (ACPA⁺) RA through an interaction with the shared epitope. After smoking cessation, there is, however, a latency of up to 20 years to return to baseline risk. Other associations are less definitive; however, prospective studies suggest that dietary antioxidants and breastfeeding may be protective and that high coffee consumption may increase RA risk. An inverse association with alcohol intake (especially in smokers) and with education/social class (especially seropositive RA) and an increased risk with obesity (seronegative RA) is also noted.

Conclusion. There is a need for further large-scale prospective studies with a consistent definition of RA phenotype (undifferentiated IP through to ACPA⁺/RF⁺ disease). This will ultimately afford the opportunity to evaluate preventative population strategies for RA akin to the well-established programmes for cardiovascular disease and cancer, targeting common risk factors.

Rheumatoid arthritis in Burkina Faso: clinical and serological profiles

The objective of this work was to study the clinical and serological profiles of rheumatoid arthritis in Burkina Faso (West Africa). It is a cross-sectional study conducted from March 2006 to February 2009 in the Internal Medicine Department of the University Hospital Yalgado Ouedraogo. All patients seen in the rheumatologic consultation unit during this period, with rheumatoid arthritis fulfilling the ACR criteria, were routinely selected. The determination of anticyclic citrullinated peptide antibodies (ACPA) was carried out with a computerized method (Elia CCP, Phadia AB, Uppsala, Sweden). Values higher than 10 IU/l were considered positive. Forty-eight cases of rheumatoid arthritis (RA) were recruited throughout the study period among 2,194 (2.2 %) patients. Forty-two files were subjected to the study. There were 34 women and 8 men. The average age was 41.70 ± 13 years with extremes of 22 and 71 years. The average duration of the disease was 86.17 ± 82.01 months with extremes of 8 and 360 months. Rheumatoid factors (RF) were positive in 21 out of 30 patients (70.0%). The determination of ACPA carried out in all the patients was positive in 34 (81%) patients; their average value was 217 IU/l with extremes of 38 and 1,170. RF and ACPA were associated to bones erosions (p = 0.0001). Twenty-two patients were placed on methotrexate, eight on hydroxychloroquine, and three on salazopyrine. Nine were given only NSAIDs or prednisolone. No patients had had a biotherapy agent. The frequency of RA was low in our study compared to other African studies published so far. The particularity of RA cases reported in African series, including ours, is the rarity of extra-articular manifestations of the disease. The severity of the disease at presentation in the rheumatology clinic may be due to their late consultation among other causes.

Environmental agents and autoimmune diseases

Autoimmune diseases, which comprise over 80 clinically distinct conditions, are characterized by the presence of autoantibodies or autoreactive T cells directed against self structures (autoantigens). While these often incurable disorders appear to be rapidly increasing in recognition throughout the world, their rarity, heterogeneity and complex etiologies have limited our understanding of their pathogeneses. The precise mechanisms for the development of autoimmune diseases are not known, however, evidence from many complementary lines of investigation suggests that autoimmune diseases result from the interactions of both environmental and genetic risk factors. While considerable progress has been made in understanding multiple genetic risk factors for many autoimmune diseases, relatively little information is now available regarding the role of the environment in the development of these illnesses. This chapter examines the limited but growing evidence for the role of the environment in the development and progression of autoimmune diseases, the specific exposures that have been suspected of being involved, the possible mechanisms by which these agents may induce and sustain autoimmune processes and the approaches needed to better understand these issues in the future. Identifying the necessary and sufficient genetic and environmental risk factors for disease holds the promise of allowing for the prevention of some illnesses through avoidance of environmental risk factors by genetically susceptible individuals or via gene or other therapies to correct the effects of deleterious genetic risk factors in the case of unavoidable environmental agents.

Epidemiological Aspects of Rheumatoid Arthritis: The Sex Ratio

Many rheumatic diseases, including rheumatoid arthritis (RA) are more frequent in females than males. The objective of this article was to examine the female versus male perspective regarding prevalence/incidence, etiological factors, disease severity/outcomes, access to therapy and therapeutic responses. We also present results from some new analyses from the patient registers in Oslo to supplement existing literature in this area. We found that the prevalence of RA is higher in females than males, the incidence is 4-5 times higher below the age of 50, but above 60-70 years the female/male ratio is only about 2. Smoking is a consistent predictor of RA in males, but findings have been more inconsistent in females. We could not confirm that health status is worse in females than males when corrections were made for different disease duration and for the underlying tendency of healthy females to report worse subjective health status than males. Some studies and data presented here indicate that females have less access to health services. We also found that female sex reduces the likelihood of achieving treatment response with methotrexate and anti-tumor necrosis factor (anti-TNF) drugs by 30-50%. More research is needed to fully describe the differences between males and females regarding epidemiological data.

Smoking is a risk factor for anti-CCP antibodies only in rheumatoid arthritis patients who carry HLA-DRB1 shared epitope alleles

OBJECTIVES

To study the gene-environment interaction of tobacco exposure and shared epitope on autoantibodies in patients with rheumatoid arthritis and undifferentiated arthritis.

METHODS

From incident cases of arthritis (n = 1305), patients who did not fulfil any classification criteria (undifferentiated arthritis (n = 486)) and those who fulfilled the American College of Rheumatology criteria for rheumatoid arthritis (n = 407) were identified. IgM rheumatoid factor (RF), anti-cyclic-citrullinated peptide (CCP) antibodies, and HLA-DRB1 alleles were determined.

RESULTS

In rheumatoid arthritis, an interaction was found between tobacco exposure and shared epitope for the presence of anti-CCP antibodies, as the odds ratio for anti-CCP antibodies in patients having both tobacco exposure (TE) and shared epitope (SE) was higher than the summed odds ratios of patients having only tobacco exposure or shared epitope (odds ratios: TE+/SE-, 1.07; TE-/SE+, 2.49; and TE+/SE+, 5.27-all relative to TE-/SE-). A similar effect was found for RF, but stratification showed that the interaction primarily associated with the anti-CCP antibody response. In patients with undifferentiated arthritis at two weeks, or with persistent undifferentiated arthritis after one year, no interaction between tobacco exposure and shared epitope was observed for the presence of autoantibodies.

CONCLUSIONS

Tobacco exposure increases the risk factor for anti-CCP antibodies only in shared epitope positive patients with rheumatoid arthritis. The gene-environment interaction between smoking and shared epitope leading to autoantibodies is specific for rheumatoid arthritis and is not observed in undifferentiated arthritis.

[Atherosclerosis and rheumatoid arthritis]

AIMS

To identify studies which have shown that rheumatoid arthritis (RA) is associated with an increase in cardiovascular morbidity and mortality. To identify the different factors that may be involved. To consider what management would decrease the cardiovascular morbidity and mortality of RA.

RESULTS

Epidemiological studies have shown that the risk of a cardiovascular event is increased twofold in RA patients irrespective of the traditional cardiovascular risk factors. Non-invasive methods have shown that RA patients have endothelial dysfunction, decreased arterial compliance and increased intima-media thickers, predictive factors for cardiovascular events in comparison to controls after controlling for traditional cardiovascular risk factors. The increased cardiovascular risk is directly mediated by inflammatory syndrome, which also indirectly increases the risk by inducing dyslipidemia and insulin resistance. Treatments also have a hamful effect, whether it be corticosteroid therapy, non-steroidal anti-inflammatory drugs (NSAIDs), or methotrexate (MTX), which leads to hyperhromocysteinemia.

CONCLUSION

It should be possible to decrease cardiovascular morbidity and mortality by a strict control of the disease's activity. We should also take measures to combat other cardiovascular risk factors: as low a dose as possible for corticosteroid therapy, limited prescription of NSAIDs, systematic supplementation of MTX with folic acid encouragement of smoking cessation, regular lipid tests and prescription of statins treatment for hyperlipemia in accordance with current recommendations.