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Objective: Racial and ethnic disparities in rheumatoid arthritis (RA) outcomes are well recognized. However, whether disparities in RA treatment selection and outcomes differ by urban versus rural residence, independent of race, have not been studied. Our objective was to evaluate whether biologic disease‐modifying antirheumatic drug (bDMARD) initiation after methotrexate administration differs by rural versus urban residence among veterans with RA. Methods: In this retrospective cohort study using national US Veterans Affairs (VA) databases, we identified adult patients with RA based on the presence of diagnostic codes and DMARD administration. We included patients receiving an initial prescription of methotrexate (index date) between 2005 and 2014, with data through 2016 used for follow‐up. Urban–rural status was categorized using the Veteran Health Administration's Urban/Rural classification. Our primary outcome of interest was time to biologic initiation within two years of starting methotrexate. Multivariable Cox proportional hazards models were conducted adjusting for demographics, comorbidities, and rheumatoid factor or anti‐cyclic citrullinated peptide positivity. Results: Among 17,395 veterans with RA (88% male, 42% with rural residence) fulfilling eligibility criteria, 3,259 (19%) initiated a biologic within the first two years of follow‐up. In multivariable models, residence in an urban area was associated with a statistically significant higher biologic administration compared to rural areas (adjusted hazard ratio 1.10 [95% confidence interval 1.02–1.18]). Conclusion: Our study found only modest differences in the initiation of biologic therapies among rural‐ versus urban‐residing veterans with RA in the VA health care system. These findings suggest that disparities are not easily explained by rurality within the VA health care system. [ABSTRACT FROM AUTHOR]

Objective: We aimed to evaluate lung cancer risk in patients with rheumatoid arthritis (RA) and RA‐interstitial lung disease (ILD). Methods: We performed a retrospective, matched cohort study of RA and RA‐ILD within the Veterans Health Administration (VA) between 2000 and 2019. Patients with RA and RA‐ILD were identified with validated administrative‐based algorithms, then matched (up to 1:10) on age, gender, and VA enrollment year to individuals without RA. Lung cancers were identified from a VA oncology database and the National Death Index. Conditional Cox regression models assessed lung cancer risk adjusting for race, ethnicity, smoking status, Agent Orange exposure, and comorbidity burden among matched individuals. Several sensitivity analyses were performed. Results: We matched 72,795 patients with RA with 633,937 patients without RA (mean age 63 years; 88% male). Over 4,481,323 patient‐years, 17,099 incident lung cancers occurred. RA was independently associated with an increased lung cancer risk (adjusted hazard ratio [aHR] 1.58 [95% confidence interval (CI) 1.52–1.64]), which persisted in never smokers (aHR 1.65 [95% CI 1.22–2.24]) and in those with incident RA (aHR 1.54 [95% CI 1.44–1.65]). Compared to non‐RA controls, prevalent RA‐ILD (n = 757) was more strongly associated with lung cancer risk (aHR 3.25 [95% CI 2.13–4.95]) than RA without ILD (aHR 1.57 [95% CI 1.51–1.64]). Analyses of both prevalent and incident RA‐ILD produced similar results (RA‐ILD vs non‐RA aHR 2.88 [95% CI 2.45–3.40]). Conclusion: RA was associated with a >50% increased risk of lung cancer, and those with RA‐ILD represented a particularly high‐risk group with an approximate three‐fold increased risk. Increased lung cancer surveillance in RA, and especially RA‐ILD, may be a useful strategy for reducing the burden posed by the leading cause of cancer death. [ABSTRACT FROM AUTHOR]

ObjectiveThe C-reactive protein (CRP) level and erythrocyte sedimentation rate (ESR) are important disease activity biomarkers in rheumatoid arthritis (RA). This study aimed to determine to what extent obesity biases these biomarkers.MethodsBody mass index (BMI) associations with CRP level and ESR were assessed in 2 RA cohorts: the cross-sectional Body Composition (BC) cohort (n = 451), including whole-body dual x-ray absorptiometry measures of fat mass index; and the longitudinal Veterans Affairs Rheumatoid Arthritis (VARA) registry (n = 1,652), using multivariable models stratified by sex. For comparison, associations were evaluated in the general population using the National Health and Nutrition Examination Survey.ResultsAmong women with RA and in the general population, greater BMI was associated with greater CRP levels, especially among women with severe obesity (P < 0.001 for BMI ≥35 kg/m2 versus 20-25 kg/m2 ). This association remained after adjustment for joint counts and patient global health scores (P < 0.001 in BC and P < 0.01 in VARA), but was attenuated after adjustment for fat mass index (P = 0.17). Positive associations between BMI and ESR in women were more modest. In men with RA, lower BMI was associated with higher CRP levels and ESR, contrasting with positive associations among men in the general population.ConclusionObesity is associated with higher CRP levels and ESR in women with RA. This association is related to fat mass and not RA disease activity. Low BMI is associated with higher CRP levels in men with RA; this unexpected finding remains incompletely explained but likely is not a direct effect of adiposity.

Purpose We evaluated associations between adiponectin and the risk of diabetes among patients with rheumatoid arthritis (RA), a systemic inflammatory disease associated with metabolic disturbance. Methods This prospective cohort study included adults with RA from the Veterans Affairs Rheumatoid Arthritis Registry. Adiponectin and inflammatory cytokines/chemokines were measured at enrollment on stored serum samples. Adiponectin levels were categorized, and clinical variables were described across categories (<10 μg/mL; 10-40 μg/mL; >40 μg/mL). Multivariable Cox proportional hazard models evaluated associations between adiponectin and incident diabetes adjusting for age, sex, race, smoking status, body mass index (BMI), disease-modifying therapy use, calendar year, and comorbidity. Testing for modification of effect in the context of elevated cytokines/chemokines was performed. Results Among 2595 patients included in the analysis, those with adiponectin levels >40 μg/mL (N = 379; 15%) were older and had lower BMI. There were 125 new cases of diabetes among 1689 patients without prevalent disease at enrollment. There was an inverse association between adiponectin and incident diabetes; however, the association was positive among patients with adiponectin levels >40 μg/mL. Patients with levels >40 μg/mL were at higher risk compared to those with levels 10-40 μg/mL (HR: 1.70 [1.34, 2.16] P <.001). Those with adiponectin levels >40 μg/mL had significantly higher levels of inflammatory cytokines with evidence of a modified effect of adiponectin on diabetes risk in the setting of inflammation. Conclusion The relationship between adiponectin and incident diabetes risk is U-shaped in RA. Patients with very high adiponectin levels have greater systemic inflammation and an altered relationship between adiponectin and diabetes risk. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study is to determine the associations of protein‐specific anti–malondialdehyde‐acetaldehyde (MAA) antibodies with prevalent and incident rheumatoid arthritis–interstitial lung disease (RA‐ILD). Methods: Within a multicenter, prospective cohort of US veterans with RA, RA‐ILD was validated by medical record review of clinical diagnoses, chest imaging, and pathology. Serum antibodies to MAA‐albumin, MAA‐collagen, MAA‐fibrinogen, and MAA‐vimentin (IgA, IgM, and IgG) were measured by a standardized enzyme‐linked immunosorbent assay. Associations of anti‐MAA antibodies with prevalent and incident RA‐ILD were assessed using multivariable regression models adjusting for established RA‐ILD risk factors. Results: Among 2,739 participants with RA (88% male, mean age of 64 years), there were 114 with prevalent and 136 with incident RA‐ILD (average time to diagnosis: 6.6 years). Higher IgM anti–MAA‐collagen (per 1 SD: adjusted odds ratio [aOR] 1.28, 95% confidence interval [CI] 1.02–1.61), IgA anti–MAA‐fibrinogen (aOR 1.48, 95% CI 1.14–1.92), and IgA (aOR 1.78, 95% CI 1.34–2.37) and IgG (aOR 1.48, 95% CI 1.14–1.92) anti–MAA‐vimentin antibodies were associated with prevalent RA‐ILD. In incident analyses, higher IgA (per one SD: adjusted hazards ratio [aHR] 1.40, 95% CI 1.11–1.76) and IgM (aHR 1.29, 95% CI 1.04–1.60) anti–MAA‐albumin antibody concentrations were associated with increased ILD risk. Participants with IgA (aHR 2.13, 95% CI 1.16–3.90) or IgM (aHR 1.98, 95% CI 1.08–3.64) anti–MAA‐albumin antibody concentrations in the highest quartile had an approximately two‐fold increased risk of incident RA‐ILD. Across all isotypes, anti–MAA‐fibrinogen, anti–MAA‐collagen, and anti–MAA‐vimentin antibodies were not significantly associated with incident RA‐ILD. Conclusion: Protein‐specific anti‐MAA antibodies to collagen, fibrinogen, and vimentin were associated with prevalent RA‐ILD. IgA and IgM anti–MAA‐albumin antibodies were associated with a higher risk of incident RA‐ILD. These findings suggest that MAA modifications and resultant immune responses may contribute to RA‐ILD pathogenesis. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the associations of plasma matrix metalloproteinases (MMPs) with prevalent and incident interstitial lung disease (ILD) in people with rheumatoid arthritis (RA). Methods: Within a multicenter, prospective cohort of US veterans with RA, we performed a cross‐sectional study of prevalent ILD and cohort study of incident ILD. ILD diagnoses were validated by medical record review of provider diagnoses and chest imaging and/or pathology reports. MMP‐1, 3, 7, and 9 concentrations were measured in plasma samples, then standardized and categorized into quartiles. The associations of MMPs with prevalent and incident ILD were assessed with logistic (prevalent) and Cox (incident) regression models adjusted for RA‐ILD risk factors. Results: Among 2,312 participants (88.9% male; mean age 63.8 years), 96 had prevalent ILD. Incident ILD developed in 130 participants over 17,378 person‐years of follow‐up (crude incidence rate 7.5/1,000 person‐years). Participants with the highest quartile of MMP‐7 concentrations had a nearly four‐fold increased odds of prevalent ILD (adjusted odds ratio 3.78 [95% confidence interval (95% CI) 1.86–7.65]) and over two‐fold increased risk of incident ILD (adjusted hazard ratio 2.33 [95% CI 1.35–4.02]). Higher MMP‐9 concentrations were also associated with prevalent and incident ILD, as well as negatively correlated with forced vital capacity among those with prevalent ILD (r = −0.30, P = 0.005). Conclusion: MMP‐7 and MMP‐9 were strongly associated with both prevalent and incident ILD in this large, multicenter RA cohort after adjustment for other RA‐ILD risk factors. These population‐level findings further support a potential pathogenic role for MMPs in RA‐ILD and suggest that their measurement could facilitate RA‐ILD risk stratification. [ABSTRACT FROM AUTHOR]

Objectives To quantify associations of serum alarmins with risk of rheumatoid arthritis-associated interstitial lung disease (RA-ILD). Methods Using serum collected at enrolment, three alarmins (IL-33, thymic stromal lymphopoietin [TSLP] and IL-25) were measured in a multicentre prospective RA cohort. ILD was classified using systematic medical record review. Cross-sectional associations of log-transformed (IL-33, TSLP) or quartile (IL-25) values with RA-ILD at enrolment (prevalent RA-ILD) were examined using logistic regression, while associations with incident RA-ILD developing after enrolment were examined using Cox proportional hazards. Covariates in multivariate models included age, sex, race, smoking status, RA disease activity score and anti-cyclic citrullinated antibody positivity. Results Of 2835 study participants, 115 participants (4.1%) had prevalent RA-ILD at baseline and an additional 146 (5.1%) developed incident ILD. There were no associations between serum alarmin concentrations and prevalent ILD in unadjusted or adjusted logistic regression models. In contrast, there was a significant inverse association between IL-33 concentration and the risk of developing incident RA-ILD in unadjusted (hazard ratio [HR] 0.73 per log-fold increase; 95% CI: 0.57, 0.95; P  = 0.018) and adjusted (HR 0.77; 95% CI: 0.59, 1.00; P  = 0.047) models. No significant associations of TSLP or IL-25 with incident ILD were observed. Conclusion In this study, we observed a significant inverse association between serum IL-33 concentration and the risk of developing incident RA-ILD, but no associations with prevalent ILD. Additional investigation is required to better understand the mechanisms driving this relationship and how serum alarmin IL-33 assessment might contribute to clinical risk stratification in patients with RA. [ABSTRACT FROM AUTHOR]

Abstract Introduction A deletion polymorphism in glutathione S-transferase Mu-1 (GSTM1-null) has previously been implicated to play a role in rheumatoid arthritis (RA) risk and progression, although no prior investigations have examined its associations with anticitrullinated protein antibody (ACPA) positivity. The purpose of this study was to examine the associations of GSTM1-null with ACPA positivity in RA and to assess for evidence of interaction between GSTM1 and HLA-DRB1 shared epitope (SE). Methods Associations of GSTM1-null with ACPA positivity were examined separately in two RA cohorts, the Veterans Affairs Rheumatoid Arthritis (VARA) registry (n = 703) and the Study of New-Onset RA (SONORA; n = 610). Interactions were examined by calculating an attributable proportion (AP) due to interaction. Results A majority of patients in the VARA registry (76%) and SONORA (69%) were positive for ACPA with a similar frequency of GSTM1-null (53% and 52%, respectively) and HLA-DRB1 SE positivity (76% and 71%, respectively). The parameter of patients who had ever smoked was more common in the VARA registry (80%) than in SONORA (65%). GSTM1-null was significantly associated with ACPA positivity in the VARA registry (odds ratio (OR), 1.45; 95% confidence interval (CI), 1.02 to 2.05), but not in SONORA (OR, 1.00; 95% CI, 0.71 to 1.42). There were significant additive interactions between GSTM1 and HLA-DRB1 SE in the VARA registry (AP, 0.49; 95% CI, 0.21 to 0.77; P < 0.001) in ACPA positivity, an interaction replicated in SONORA (AP, 0.38; 95% CI, 0.00 to 0.76; P = 0.050). Conclusions This study is the first to show that the GSTM1-null genotype, a common genetic variant, exerts significant additive interaction with HLA-DRB1 SE on the risk of ACPA positivity in RA. Since GSTM1 has known antioxidant functions, these data suggest that oxidative stress may be important in the development of RA-specific autoimmunity in genetically susceptible individuals.

Purpose: To develop a natural language processing (NLP) tool to extract forced vital capacity (FVC) values from electronic health record (EHR) notes in patients with rheumatoid arthritis‐interstitial lung disease (RA‐ILD). Methods: We selected RA‐ILD patients (n = 7485) in the Veterans Health Administration (VA) between 2000 and 2020 using validated ICD‐9/10 codes. We identified numeric values in proximity to FVC string patterns from clinical notes in the EHR. Subsequently, we performed processing steps to account for variability in note structure, related pulmonary function test (PFT) output, and values copied across notes, then assigned dates from linked administrative procedure records. NLP‐derived FVC values were compared to values recorded directly from PFT equipment available on a subset of patients. Results: We identified 5911 FVC values (n = 1844 patients) from PFT equipment and 15 383 values (n = 4982 patients) by NLP. Among 2610 date‐matched FVC values from NLP and PFT equipment, 95.8% of values were within 5% predicted. The mean (SD) difference was 0.09% (5.9), and values strongly correlated (r = 0.94, p < 0.001), with a precision of 0.87 (95% CI 0.86, 0.88). NLP captured more patients with longitudinal FVC values (n = 3069 vs. n = 1164). Mean (SD) change in FVC %‐predicted per year was similar between sources (−1.5 [30.0] NLP vs. −0.9 [16.6] PFT equipment; standardized response mean = 0.05 for both). Conclusions: NLP of EHR notes increases the capture of accurate, longitudinal FVC values by three‐fold over PFT equipment. Use of this NLP tool can facilitate pharmacoepidemiologic research in RA‐ILD and other lung diseases by capturing this critical measure of disease severity. [ABSTRACT FROM AUTHOR]

Objective: Patients with rheumatoid arthritis (RA) have an increased risk of select cancers, including lymphoma and lung cancer. Whether RA influences prostate cancer risk is uncertain. We aimed to determine the risk of prostate cancer in patients with RA compared to patients without RA in the Veterans Health Administration (VA). Methods: We performed a matched (up to 1:5) cohort study of male patients with and without RA in the VA from 2000 to 2018. RA status, as well as covariates, were obtained from national VA databases. Prostate cancer was identified through linked VA cancer databases and the National Death Index. Multivariable Cox models compared prostate cancer risk between patients with RA and patients without RA, including models that accounted for retention in the VA system. Results: We included 56,514 veterans with RA and 227,284 veterans without RA. During 2,337,104 patient‐years of follow‐up, 6,550 prostate cancers occurred. Prostate cancer incidence (per 1,000 patient‐years) was 3.50 (95% confidence interval [95% CI] 3.32–3.69) in patients with RA and 2.66 (95% CI 2.58–2.73) in patients without RA. After accounting for confounders and censoring for attrition of VA health care, RA was modestly associated with a higher prostate cancer risk (adjusted HR [HRadj] 1.12 [95% CI 1.04–1.20]). There was no association between RA and prostate cancer mortality (HRadj 0.92 [95% CI 0.73–1.16]). Conclusion: RA was associated with a modestly increased risk of prostate cancer, but not prostate cancer mortality, after accounting for relevant confounders and several potential sources of bias. However, even minimal unmeasured confounding could explain these findings. [ABSTRACT FROM AUTHOR]