RT Journal Article SR Electronic T1 Lifestyle and clinical risk factors for incident rheumatoid arthritis-associated interstitial lung disease JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP jrheum.200863 DO 10.3899/jrheum.200863 A1 Vanessa L. Kronzer A1 Weixing Huang A1 Paul F. Dellaripa A1 Sicong Huang A1 Vivi Feathers A1 Bing Lu A1 Christine K. Iannaccone A1 Ritu R. Gill A1 Hiroto Hatabu A1 Mizuki Nishino A1 Cynthia S. Crowson A1 John M. Davis III A1 Michael E. Weinblatt A1 Nancy A. Shadick A1 Tracy J. Doyle A1 Jeffrey A. Sparks YR 2020 UL http://www.jrheum.org/content/early/2020/11/10/jrheum.200863.abstract AB Objective To determine the association between novel lifestyle factors on risk of rheumatoid arthritis-associated interstitial lung disease (RA-ILD), define the threshold at which smoking increases RA-ILD risk, and calculate the degree to which known lifestyle and clinical factors predict RA-ILD. Methods This nested case-control study matched incident RA-ILD cases to RA non-ILD controls on age, sex, RA duration, rheumatoid factor, and time from exposure assessment to RA-ILD. Exposures included education, body mass index (BMI), smoking, anti-cyclic citrullinated peptide, race, joint erosions, rheumatoid nodules, C-reactive protein (CRP), disease activity score, functional status, disease-modifying anti-rheumatic drug use, and glucocorticoid use. Odds ratios (OR) for each exposure on risk of RA-ILD were obtained from logistic regression models. Area under the curve (AUC) was calculated based all lifestyle and clinical exposures. Results We identified 84 incident RA-ILD cases and 233 matched controls. After adjustment, obesity, high-positive CRP (≥10 mg/L), and poor functional status (MDHAQ ≥1) were associated with increased risk of RA-ILD (OR 2.42, 95% confidence interval [CI] 1.11-5.24 vs. normal BMI; OR 2.61, 95% CI 1.21-5.64 vs. CRP <3mg/L; OR 3.10, 95% CI 1.32-7.26 vs. MDHAQ <0.2). Smoking 30 pack-years or more was strongly associated with risk of RA-ILD compared to nonsmokers (OR 6.06, 95% CI 2.72-13.5). Together, lifestyle and clinical risk factors for RA-ILD had an AUC of 0.79 (95% CI 0.73-0.85). Conclusion Obesity, CRP, functional status, and extensive smoking may be novel risk factors for RA-ILD, useful for RA-ILD risk assessment and prevention. The overall ability to predict RA-ILD remains modest.