THU0107 BARIATRIC SURGERY DOES NOT PREVENT THE DEVELOPMENT OF RHEUMATOID ARTHRITIS IN OBESE SUBJECTS
Authors: Yuan Zhang, Anna Rudin, Cristina Maglio, Lena Carlsson
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background:</h3> Obesity is among the risk factors for rheumatoid arthritis (RA)<sup>1,2</sup>. In subjects with RA, bariatric surgery-induced weight loss has been associated with a lower disease activity, a decrease in inflammatory markers and a lower use of disease-modifying antirheumatic drugs<sup>3</sup>. However, the effect of bariatric surgery on the prevention of RA is not known. We have previously shown that bariatric surgery reduces the risk of gouty arthritis and psoriasis in obese subjects<sup>4,5</sup>. <h3>Objectives:</h3> By exploiting a longitudinal study enrolling more than 4000 obese subjects, we aim to determine if bariatric surgery prevents the incidence of RA. <h3>Methods:</h3> The Swedish Obese Subjects (SOS) study is a longitudinal controlled trial on the effect of bariatric surgery on the incidence of obesity-related diseases. It includes 4047 obese subjects: 2010 underwent bariatric surgery and 2037 constituted the matched control group<sup>6</sup>. Seven Swedish local ethics review boards approved the study protocol. SOS study participants who developed RA were identified by searching the Swedish National Patient Register. Eleven subjects with prevalent RA at baseline are excluded by the analyses. Patients were followed up until diagnosis of RA, death, migration or end of follow-up (December 2016). <h3>Results:</h3> During a follow-up for up to 29 years, 92 subjects developed RA. Fifty-one individuals (55%) had a seropositive RA (serostatus was unknown for 17 subjects). Forty-seven subjects (2.3%) developed RA in the surgery group compared to 45 subjects (2.2%) in the control group. Bariatric surgery was not associated with the incidence of RA during follow up (log-rank P=0.88; unadjusted Hazard Ratio-HR 1.03, 95% Confidence Interval-CI 0.69-1.55, P=0.88, Figure 1). Similar results were obtained if only subjects with seropositive RA were included in the analysis. Adjustment for confounding factors did not affect the results (HR for bariatric surgery after adjustment for confounding factors 0.92, 95% CI 0.58-1.45, P=0.72). <h3>Conclusion:</h3> In a large cohort of obese subjects followed up for up to 29 years, bariatric surgery did not affect the incidence of RA years. <h3>References:</h3> [1] Qin B, Yang M, Fu H, et al. Body mass index and the risk of rheumatoid arthritis: a systematic review and dose-response meta-analysis. Arthritis Res Ther 2015;17:86. [2] Lu B, Hiraki LT, Sparks JA, et al. Being overweight or obese and risk of developing rheumatoid arthritis among women: a prospective cohort study. Ann Rheum Dis 2014;73:1914-22. [3] Sparks JA, Halperin F, Karlson JC, Karlson EW, Bermas BL. Impact of Bariatric Surgery on Patients With Rheumatoid Arthritis. Arthritis Care Res (Hoboken) 2015;67:1619-26. [4] Maglio C, Peltonen M, Neovius M, et al. Effects of bariatric surgery on gout incidence in the Swedish Obese Subjects study: a non-randomised, prospective, controlled intervention trial. Ann Rheum Dis 2016. [5] Maglio C, Peltonen M, Rudin A, Carlsson LMS. Bariatric Surgery and the Incidence of Psoriasis and Psoriatic Arthritis in the Swedish Obese Subjects Study. Obesity (Silver Spring) 2017;25:2068-73. [6] Sjöström L, Narbro K, Sjöström CD, et al. Effects of bariatric surgery on mortality in Swedish obese subjects. N Engl J Med 2007;357:741-52. <h3>Abbreviations:</h3> HR, hazard ratio; C.I., confidence interval. <h3>Disclosure of Interests:</h3> Yuan Zhang: None declared, Anna Rudin Grant/research support from: I have received research grants från AstraZeneca (2017-2018), Consultant for: I was paid consultant för AstraZeneca (2015-2018), Cristina Maglio: None declared, Lena Carlsson Consultant for: I have received lecture fees from AstraZeneca, MSD and Johnson&amp;Johnson