Rheumatoid Arthritis Odds Ratio Research Articles

Increased risk of rheumatoid arthritis in patients with asthma: a genetic association study using two-sample Mendelian randomization analysis.

Observational studies have explored the association between asthma and some types of arthritis, including rheumatoid arthritis and osteoarthritis, but the results are largely contradictory. We aimed to investigate the causal effects of asthma on arthritis including osteoarthritis, rheumatoid arthritis, gout and ankylosing spondylitis. Two-sample Mendelian randomization (MR) analysis was used to investigate the causal effects of asthma on each arthritis. The genetic instruments for asthma were obtained from a large genome-wide association study of asthma. Inverse-variance weighted (IVW) method was used as the main analysis of MR. Bonferroni-adjusted P value threshold was used to account for multiple comparisons. MR-IVW analysis suggested that adult-onset asthma (AOA) was associated with increased risk of rheumatoid arthritis. The odds ratio for rheumatoid arthritis associated with AOA and childhood-onset asthma (COA) were 1.018 (95% CI, 1.011 to 1.025; P < 0.001) and 1.006 (95% CI, 1.001 to 1.012; P=0.046), respectively. For osteoarthritis, gout, or ankylosing spondylitis, all the MR analyses showed no significant causal effects of AOA or COA on them. We also performed a reverse MR analysis to explore the causal effects of rheumatoid on all asthma, allergic asthma or non-allergic asthma, and found no significant causal effects on them. Genetically predicted AOA predisposes patients to an increased risk of rheumatoid arthritis, but has no causal effects on osteoarthritis, gout, and ankylosing spondylitis. The result of COA on rheumatoid arthritis is suggestive of potential causal relationship but needs to be confirmed in further studies.

Self-reported and genetically predicted effects of coffee intake on rheumatoid arthritis: Epidemiological studies and Mendelian randomization analysis.

Background and aimsCausal research concerning coffee intake and rheumatoid arthritis (RA) risk is controversial. The objective of this study was to further explore the causal relationship between coffee intake and RA risk.MethodsThe 4,310 participants from NHANES 2003–2006 were included in an epidemiological study to assess the association between coffee intake and RA by weighted multivariate logistic regression. The inverse variance weighted (IVW) method of two-sample Mendelian randomization (MR), employing genetic data from UK Biobank (428,860 cases) of coffee intake and MR-Base platform (14,361 cases and 43,923 controls) of RA, was performed to estimate the causal relationship between coffee intake and RA.ResultsWeighted multivariate logistic regression suggested no significant correlation between coffee intake and RA. Compared to the no-coffee group, the odds ratio for RA in the <1, 1–3, ≥4 cups/day group were 1.297, 1.378, and 1.125 (P = 0.204, 0.098, and 0.698, respectively). In the IVW of MR analysis, there was no causal relationship between coffee intake and RA (OR = 1.47, P = 0.218).ConclusionOur study did not support a causal association between coffee intake and RA risk. However, it is necessary to consider valid information on coffee intake, including brewing method, type of coffee, and quantity, in further analysis of coffee intake and RA.

Evaluated serum perfluoroalkyl acids and their relationships with the incidence of rheumatoid arthritis in the general population in Hangzhou, China

Perfluoroalkyl acids (PFAAs) are widely present in human blood, and have many toxic effects on humans. However, effects of PFAA exposure on the risk of rheumatic immune diseases are limited. In the present study, occurrence of 7 PFAAs, including perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoate (PFNA), perfluorodecanoate (PFDA), perfluoroundecanoate (PFUnA), perfluorododecanoate (PFDoA), and perfluorotrdecanoate (PFTrA), were measured in serum samples from 156 healthy people (controls) and 156 rheumatoid arthritis (RA) cases living in Hangzhou, China. We also investigated the relationships among cumulative PFAA levels in serum, some immune markers, and the incidence of RA. The results showed that PFOA (6.1 and 11.8 ng/mL) had the highest mean serum concentrations, followed by PFOS (3.2 and 3.4 ng/mL) and PFDA (0.86 and 2.6 ng/mL), in both controls and RA cases. Cumulative exposure to PFOA in the study population were positively correlated with the levels of rheumatoid factors (rs = 0.69, p < 0.01) and anti-cyclic citrullinated peptide antibody (rs = 0.56, p < 0.05). Moreover, significant associations of PFOA concentrations with odds ratios (OR) of RA (OR = 1.998, confidence interval (CI): 1.623, 2.361, p = 0.01) were found by adjusting for various covariates. The crude and adjusted OR for RA was respective 1.385 (95% CI: 1.270, 1.510, p = 0.04) and 1.381 (95% CI: 0.972, 1.658, p = 0.06) for a unit increase in serum PFOS levels, but the adjusted results were not significant. Overall, this case-control study found that human serum PFOA concentrations were positively correlated with RF and ACPA levels.

Is Rheumatoid Arthritis Related to Coffee Consumption in Korea? A Nationwide Cross-Sectional Observational Study.

Coffee consumption is gradually increasing in Korea. As a result, interest in the relationship between coffee consumption and various diseases is growing. Several factors affect the development of rheumatoid arthritis (RA), and coffee consumption may be related. We conducted a nationwide cross-sectional study using data from the Korea National Health and Nutrition Examination Survey (2012–2016). A total of 12,465 eligible participants (4819 men and 7646 women) were included in the study. Participants with RA were defined as those who were diagnosed and currently being treated by physicians. Daily coffee consumption amounts were categorized as none, <1 cup, 1–2 cups, 2–3 cups, and ≥3 cups a day based on a self-report. A multivariable logistic regression model was employed, and we calculated the odds ratios (ORs) and 95% confidence intervals (CIs) for the odds of participants having RA with respect to coffee consumption. Compared to the no-coffee group, the ORs for RA in the <1 cup and 1–2 cups groups were 2.99 (95% CI 0.33–27.28) and 2.63 (95% CI 0.31–22.63) in men, respectively, and the ORs for RA for women in the <1 cup, 1–2 cups, 2–3 cups, and ≥3 cups groups were 0.62 (95% CI 0.31–1.26), 0.67 (95% CI 0.33–1.37), 1.08 (95% CI 0.35–3.36), and 1.43 (95% CI 0.25–8.36), respectively. Our study concludes, therefore, that daily coffee consumption is not related to the prevalence of RA in the general Korean population.

Silica Dust Exposure Increases Risk for Rheumatoid Arthritis: A Swedish National Registry Case-Control Study.

Objective:Rheumatoid arthritis (RA) is an inflammatory disease with unknown etiology. This study examines if silica dust exposure increases the risk for seropositive and seronegative RA.Methods:A nationwide registry case–control study was conducted that included all cases of RA in Sweden between 2005 and 2016. In total, 31,139 cases with two matched controls were included. A JEM was used to estimate exposure.Results:Silica dust exposure was associated with a statistically significant increase in odds ratio (OR) for seropositive (OR 1.22, 95% CI 1.05 to 1.40) and seronegative (OR 1.23, 95% CI 1.04 to 1.46) RA among men.Conclusion:This study found an increased OR for RA in silica-exposed men. The OR was equal for seropositive and seronegative RA. These findings further support the hypothesis that silica dust may be a trigger for RA.

Association of Actinic Keratosis with Rheumatoid Arthritis and Psoriasis: A Nationwide Population-Based Study in Korea.

There have been no epidemiological studies identifying associations between systemic inflammatory diseases and actinic keratosis. This study used a large nationwide database to investigate the associations between actinic keratosis and systemic inflammatory diseases. Records of patients over 20 years of age newly diagnosed with actinic keratosis (n = 64,659) from 2012 to 2017 were analysed. A control population of individuals without actinic keratosis, matched for age, sex, and year of claim, who visited an outpatient clinic, was sampled at a ratio of 1:1 (n = 64,659). Both cohorts were analysed for the presence of systemic inflammatory diseases within at least 5 years prior to diagnosis of actinic keratosis. Patients with actinic keratosis exhibited higher odds ratios for rheumatoid arthritis (1.336; 95% confidence interval (95% CI) 1.161–1.537)) and psoriasis (1.513; 95% CI 1.435–1.595) compared with the control group on multivariate analysis. However, the proportions of Behçet’s disease, Crohn’s disease, ulcerative colitis, and multiple sclerosis in the actinic keratosis group were not statistically significant.

Rheumatoid arthritis and neurodegenerative dementia: a nested case-control study and a follow-up study using a national sample cohort.

The present study evaluated the associations between rheumatoid arthritis (RA) and neurodegenerative dementia using a Korean national sample cohort. We designed two studies using the Korean National Health Insurance Service-National Sample Cohort from 2002 to 2013. Study I included participants with dementia matched 1:4 with controls and analyzed the participants' history of RA. Study II included participants with RA matched 1:4 with controls and analyzed the occurrence of dementia. RA was defined by the presence of relevant ICD-10 codes (M05 or M06) and medication histories. Neurodegenerative dementia was defined using ICD-10 codes (G30 or F00). Crude and adjusted odds ratios (ORs) were analyzed using conditional logistic regression analyses. Crude and adjusted hazard ratios (HRs) were analyzed using the stratified Cox proportional hazard model. Subgroup analyses were performed on groups stratified by age and sex. The adjusted ORs for RA were 0.96 (95% CI = 0.78-1.16, P = 0.644) in the dementia group in study I. The adjusted HRs for dementia were 0.91 (95% CI = 0.76-1.10, P = 0.319) in the RA group in study II. No subgroup analysis reached the statistical significance level. We could not identify any significant relationship between RA and dementia.Key Points• Two studies were conducted to identify the relationship between rheumatoid arthritis and dementia using national cohort data.• Neither study showed any association between rheumatoid arthritis and dementia.

Autoimmune/Inflammatory Syndrome Induced by Silicone Breast Implant and Risk Factors Associated to Autoimmune Diseases

Autoimmune Rheumatic Diseases (ARD) have been associated with Silicon Breast Implant (SBI) as part of the spectrum of Autoimmune/Inflammatory Syndrome Induced by Adjuvants (ASIA). Silicone is an adjuvant that may bleed and subsequently may be a chronic stimulus to the immune system. Objective: To determine the prevalence of autoimmune diseases (AID) and risk factors associated to patients with ASIA induced by SBI (ASIA-SBI). Patients and methods: This study was performed between 2012 and 2018, in a tertiary referral center, from a cohort of 210 patients with ASIA. We selected those patients with ASIA-SBI and clinical manifestations of any ARD. We investigated family history of AID, smoking, allergies and comorbidities. Statistical analysis: Chi square and Odds Ratio (OR). Results: There were 45 women with current age 50 (29-75) years, mean time of appearance of clinical manifestations after SBI was 8.8 ± 5.5 years. We found systemic sclerosis (SSc) 10 patients, rheumatoid arthritis (RA) 8, undifferentiated connective tissue syndrome (UCTDS) 6, fibromyalgia (FM) 5, systemic lupus erythematosus (SLE) 4, Sjogren syndrome (SS) 3, angioedema/urticaria 3, overlap syndrome 2, and one of each of the following: Takayasu arteritis, Still disease, tunnel carpal syndrome and antiphospholipid syndrome. We observed family history of ARD 42%, allergy history 37.5% and smoking 35.5%. In ASIA-SBI patients, family history and smoking had a significant association with SSc OR 6.0 (CI 1.2-29), p<0.02 and RA OR 7.1 (CI 1.3-37.2), p<0.022. Conclusions: In patients with ASIA-SBI, family history of AID and smoking were associated with SSc and RA. In addition to SBI, environmental and genetic factors should be taken into account for the development of AID.

High Sodium Intake Is Associated With Self-Reported Rheumatoid Arthritis: A Cross Sectional and Case Control Analysis Within the SUN Cohort.

Sodium intake is a potential environmental factor for immune-mediated inflammatory diseases. The aim of this study is to investigate the association of sodium intake with rheumatoid arthritis.We performed a cross-sectional study nested in a highly educated cohort investigating dietary habits as determinants of disease. Daily sodium intake in grams per day was estimated from a validated food frequency questionnaire. We identified prevalent self-reported cases of rheumatoid arthritis. Logistic regression models were used to estimate the odds ratio for rheumatoid arthritis by sodium intake adjusting for confounders. Linear trend tests and interactions between variables were explored. Sensitivity analyses included age- and sex-matched case–control study, logistic multivariate model adjusted by residuals, and analysis excluding individuals with prevalent diabetes or cardiovascular disease.The effective sample size was 18,555 individuals (mean age 38-years old, 60% women) including 392 self-reported rheumatoid arthritis. Median daily sodium intake (estimated from foods plus added salt) was 3.47 (P25–75: 2.63–4.55) grams. Total sodium intake in the fourth quartile showed a significant association with rheumatoid arthritis (fully adjusted odds ratio 1.5; 95% CI 1.1–2.1, P for trend = 0.02). Never smokers with high sodium intake had higher association than ever smokers with high sodium intake (P for interaction = 0.007). Dose-dependent association was replicated in the case–control study.High sodium intake may be associated with a diagnosis of rheumatoid arthritis. This confirms previous clinical and experimental research.

Factors predictive of the perceived osteoporosis–fracture link in fragility fracture patients

ObjectiveGiven the asymptomatic nature of osteoporosis, a fragility fracture provides an opportunity to make the issue of osteoporosis relevant to patients. Patients who link their fragility fracture with osteoporosis are more likely to initiate osteoporosis treatment, yet to date, we know little about who is likely to make this link. This study examined whether demographic, health, and osteoporosis belief factors predicted a perceived link between a fragility fracture and osteoporosis. Study designThis longitudinal cohort study analyzed baseline and follow up data collected as part of a provincial osteoporosis screening initiative targeting fragility fracture patients. Logistic regression analysis was used to examine the relationship between hypothesized predictors and the outcome. Main outcome measurePatient perception of the osteoporosis–fracture link at follow up. ResultsAt baseline, 93% (1615/1735) of patients did not believe their fracture could have been caused by osteoporosis. Of these, only 8.2% changed this perception at follow up. Adjusted analyses showed that baseline characteristics associated with making the osteoporosis–fracture link at follow up were: a previous fracture (odds ratio (OR) 1.7, confidence interval (CI) 1.2–2.6), perception of osteoporosis pharmacotherapy benefits OR 1.2 (CI 1.0–1.5), diagnosis of rheumatoid arthritis OR 2.6 (CI 1.4–4.9) and the perception of bones as “thin” OR 8.2 (CI 5.1–13.1). ConclusionThese results shed more light on patient-level barriers to osteoporosis management following an osteoporosis educational programme. They may be used to identify patients less likely to make the link between their fracture and osteoporosis and to inform interventions for this patient group.

Regional differences regarding risk of developing rheumatoid arthritis in Stockholm County, Sweden: results from the Swedish Epidemiological Investigation of Rheumatoid Arthritis (EIRA) study

Objectives: Rheumatoid arthritis (RA) is a complex disease that is associated with genetic and environmental factors. We have investigated geospatial variation in the risk of developing RA within Stockholm County, Sweden, with respect to established environmental risk factors for RA, as well as serologically defined subgroups of RA.Method: Information regarding geographical location for 1432 cases and 2529 controls from the Epidemiological Investigation of Rheumatoid Arthritis (EIRA) study, living in Stockholm County at RA symptom onset, or matched date for controls, was used to estimate geospatial variation in risk. We used generalized additive models (GAMs) to create a risk surface, calculate odds ratios (ORs), and adjust for potential confounding by smoking, education level, and RA within family. We performed a stratified analysis based on the presence/absence of anti-citrullinated peptide antibodies (ACPA).Results: We found significant spatial variation in the odds of developing RA in Stockholm County. After adjustment for smoking, education level, and family history of RA, this geospatial variation remained. The stratified analysis showed areas with higher ORs for ACPA-positive RA and ACPA-negative RA, after adjusting for smoking, education level, and having a family history of RA. Living in the city of Stockholm was associated with decreased risk of RA.Conclusions: The risk of developing RA in Stockholm County is not distributed evenly and there are areas of increased risk that could not be explained by known factors. Further investigations of local exposures or social factors are warranted.

Prediction model for rheumatoid arthritis: modelling 46 genetic risk variants with smoking

Background Improved characterisation of the risk factors for rheumatoid arthritis raises the possibility that they could be combined to identify individuals at high risk of disease in whom preventive strategies can be evaluated. Our aim was to develop a prediction model capable of identifying such individuals with sufficient accuracy to enable the assessment of preventive treatments. MethodsOur prediction model combines odds ratios for 15 HLA-DRB1 alleles, 31 non-HLA single nucleotide polymorphisms (SNPs), and smoking status to classify an individual's risk of seropositive rheumatoid arthritis. Our novel modelling technique employs confidence intervals to classify disease risks using a computer-simulated population. We developed several models (HLA, HLA-10/20/31 SNP, HLA-smoking models) to evaluate the impact of different factors on prediction. The ability of each model to discriminate between rheumatoid arthritis and controls was evaluated in two European cohorts: the Wellcome Trust Case Control Consortium (WTCCC: 1542 cases, 1226 controls) and the UK Rheumatoid Arthritis Genetics Consortium (UKRAG: 2623 cases, 1503 controls).Findings HLA-DRB1 alleles conferred most prediction: the WTCCC HLA-only model classified 50% antibodies to citrullinated protein antigens (ACPA)-positive rheumatoid arthritis versus 17% controls as high risk and 60% controls versus 25% ACPA-positive rheumatoid arthritis as reduced risk. Adding smoking information improved prediction (p=0·00033); SNPs provided no significant benefits. The highest area under the curve was 0·81 (95% CI 0·78–0·85). Only a minority had substantially elevated risks of rheumatoid arthritis: 6·9% ACPA-positive cases and 0·31% controls in WTCCC had an odds ratio for rheumatoid arthritis of more than 20 when evaluated with the HLA-31 SNP model. InterpretationCombined information on HLA-DRB1 alleles and smoking provides informative risk prediction for rheumatoid arthritis. Since only a minority of individuals are at substantially elevated risks, modelling may be best focused in a-priori high-risk groups such as those with family histories of rheumatoid arthritis. Further work is needed to define risk factors with large effect sizes for incorporation within our modelling framework. FundingArthritis Research UK.

Association between body mass index and anti–citrullinated protein antibody–positive and anti–citrullinated protein antibody–negative rheumatoid arthritis: Results from a population‐based case–control study

Being overweight or obese is associated with many chronic diseases, but previous studies of the association with rheumatoid arthritis (RA) have shown inconsistent results. The aim of this study was to investigate the association between body mass index (BMI) and the risk of developing the 2 main subtypes of RA. At inclusion, cases and controls answered questions about their weight and height and donated blood samples. The presence of antibodies to citrullinated protein antigens (ACPAs) was analyzed among 2,748 cases and 3,444 controls (28% men). Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using conditional logistic regression. Compared to those with normal weight (BMI <25 kg/m(2) ), the adjusted overall OR for developing ACPA-negative RA was 1.1 (95% CI 0.9-1.3) for overweight individuals (BMI ≥25 to <30 kg/m(2) ) and 1.4 (95% CI 1.1-1.9) for obese individuals (BMI ≥30 kg/m(2) ). When stratified by sex, the OR for ACPA-negative RA for obese women was 1.6 (95% CI 1.2-2.2), and there was no association between obesity and ACPA-negative RA in men (OR 1.1, 95% CI 0.6-1.8). In obese men compared to men with normal weight, the OR for ACPA-positive RA was 0.6 (95% CI 0.3-0.9), while there was no association between BMI and ACPA-positive RA among women (OR 1.0, 95% CI 0.8-1.2). Our findings show that obesity is associated with developing ACPA-negative RA in women, and indicate an inverse association between BMI and ACPA-positive RA in men.

A case–control study on the association between rheumatoid arthritis and bladder pain syndrome/interstitial cystitis

While bladder pain syndrome/interstitial cystitis (BPS/IC) has been suggested by a number of studies to have autoimmune character, no population-based study to date has been conducted investigating its association with rheumatoid arthritis (RA). This study aimed to examine the association between IC/BPS and having previously been diagnosed with RA. We conducted this study by using administrative claims data sourced from the Taiwan National Health Insurance Database. Our study included 9,269 cases with BPS/IC and 46,345 randomly selected controls. Conditional logistic regression was performed to calculate the odds ratio (OR) for the association between previously diagnosed RA and IC/BPS. RA was found among 202 (2.2%) cases and 504 (1.12%) controls. Conditional logistic regression analysis suggested that when compared with controls, the OR for prior RA among cases was 1.66 (95% CI = 1.47-1.87, P < 0.001) after adjusting for diabetes, hypertension, coronary heart disease, obesity, hyperlipidemia, chronic pelvic pain, irritable bowel syndrome, fibromyalgia, chronic fatigue syndrome, depression, panic disorder, migraine, sicca syndrome, allergy, endometriosis, asthma, overactive bladder, tobacco use disorder, and alcohol abuse. Additionally, BPS/IC was consistently and significantly associated with a previous diagnosis of RA regardless of prescription drug use; the OR for prior RA among groups prescribed ≤1 type of disease-modifying antirheumatic drug (DMARD), two types of DMARDs, and ≥3 types of DMARDs or TNF-alpha inhibitor when compared to controls were 1.49 (95% CI = 1.28-1.72), 1.91 (95% CI = 1.38-2.68), and 2.36 (95% CI = 1.77-3.17), respectively. There is an association between RA and BPS/IC after adjusting for socio-demographic characteristics and medical co-morbidities.

Periodontal disease, tooth loss and incident rheumatoid arthritis: results from the First National Health and Nutrition Examination Survey and its epidemiological follow-up study.

Infection may be a rheumatoid arthritis (RA) risk factor. We examined whether signs of periodontal infection were associated with RA development in the First National Health and Nutrition Examination Survey and its epidemiological follow-up study. In 1971-1974, 9702 men and women aged 25-74 were enrolled and surveyed longitudinally (1982, 1986, 1987, 1992). Periodontal infection was defined by baseline tooth loss or clinical evidence of periodontal disease. Baseline (n = 138) and incident (n = 433) RA cases were defined via self-report physician diagnosis, joint pain/swelling, ICD-9 codes (714.0-714.9), death certificates and/or RA hospitalization. Adjusted odds ratios (ORs) (95% CI) for prevalent RA in gingivitis and periodontitis (versus healthy) were 1.09 (0.57, 2.10) and 1.85 (0.95, 3.63); incident RA ORs were 1.32 (0.85, 2.06) and 1.00 (0.68, 1.48). The ORs for prevalent RA among participants missing 5-8, 9-14, 15-31 or 32 teeth (versus 0-4 teeth) were 1.74 (1.03, 2.95), 1.82 (0.81, 4.10), 1.45 (0.62, 3.41) and 1.30 (0.48, 3.53); ORs for incident RA were 1.12 (0.77, 1.64), 1.67 (1.12, 2.48), 1.40 (0.85, 2.33) and 1.22 (0.75, 2.00). Dose-responsiveness was enhanced among never smokers. The rate of death or loss-to-follow-up after 1982 was two- to fourfold higher among participants with periodontitis or missing ≥9 teeth (versus healthy participants). Although participants with periodontal disease or ≥5 missing teeth experienced higher odds of prevalent/incident RA, most ORs were non-statistically significant and lacked dose-responsiveness. Differential RA ascertainment bias complicated the interpretation of these data.

Association of STAT4 with susceptibility to rheumatoid arthritis and systemic lupus erythematosus in the Japanese population

STAT4 encodes a transcriptional factor that transmits signals induced by several key cytokines, and it might be a key molecule in the development of autoimmune diseases. Recently, a STAT4 haplotype was reported to be associated with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) in Caucasian populations. This was replicated in a Korean RA population. Interestingly, the degree of risk of RA susceptibility with the STAT4 haplotype was similar in the Caucasian and Korean populations. The present study was undertaken to investigate the effect of STAT4 on susceptibility to RA and SLE in the Japanese. We performed an association study using 3 independent Japanese RA case-control populations (total 3,567 cases and 2,199 controls) and 3 independent Japanese SLE populations (total 591 cases). All samples were genotyped using the TaqMan fluorogenic 5' nuclease assay for single-nucleotide polymorphism (SNP) rs7574865, which tags the susceptibility haplotype. The association of the SNP with disease susceptibility in each case-control study was calculated using Fisher's exact test, and the results were combined, using the Mantel-Haenszel method, to obtain combined odds ratios (ORs). We observed a significant association of the STAT4 polymorphism with susceptibility to both RA and SLE. The combined ORs for RA and SLE, respectively, were 1.27 (P = 8.4 x 10(-9)) and 1.61 (P = 2.1 x 10(-11)) for allele frequency distribution; these ORs were quite similar to those previously observed in the Caucasian population. We conclude that STAT4 is associated with RA and SLE in the Japanese. Our results indicate that STAT4 is a common genetic risk factor for autoimmune diseases, with similar strength across major racial groups.

Positive Associations of Serum Concentration of Polychlorinated Biphenyls or Organochlorine Pesticides with Self-Reported Arthritis, Especially Rheumatoid Type, in Women

BackgroundPersistent organic pollutants (POPs) can influence the immune system, possibly increasing the risk of rheumatoid arthritis (RA). In addition, as metabolic change due to obesity has been proposed as one mechanism of osteoarthritis (OA), POPs stored in adipose tissue may be also associated with OA.ObjectiveOur goal in this study was to examine associations of background exposure to POPs with arthritis among the general population.DesignWe investigated cross-sectional associations of serum POPs concentrations with the prevalence of self-reported arthritis in 1,721 adults ≥ 20 years of age in the National Health and Nutrition Examination Survey 1999–2002.ResultsAmong several POPs, dioxin-like polychlorinated biphenyls (PCBs) or nondioxin-like PCBs were positively associated with arthritis in women. After adjusting for possible confounders, odds ratios (ORs) were 1.0, 2.1, 3.5, and 2.9 across quartiles of dioxin-like PCBs (p for trend = 0.02). Corresponding figures for nondioxin-like PCBs were 1.0, 1.6, 2.6, and 2.5 (p for trend = 0.02). Organochlorine (OC) pesticides were also weakly associated with arthritis in women. For subtypes of arthritis, respectively, RA was more strongly associated with PCBs than was OA. The adjusted ORs for RA were 1.0, 7.6, 6.1, and 8.5 for dioxin-like PCBs (p for trend = 0.05), 1.0, 2.2, 4.4, and 5.4 for nondioxin-like PCBs (p for trend < 0.01), and 1.0, 2.8, 2.7, and 3.5 for OC pesticides (p for trend = 0.15). POPs in men did not show any clear relation with arthritis.ConclusionsThe possibility that background exposure to PCBs may be involved in pathogenesis of arthritis, especially RA, in women should be investigated in prospective studies.