Background/Purpose: Obesity causes a chronic inflammatory state. Increased body mass index (BMI) is associated with incident rheumatoid arthritis (RA) and may impact RA disease activity. We hypothesized that bariatric surgery, which results in substantial weight loss and decreased inflammatory markers, may improve RA disease activity.

Methods: We conducted a retrospective cohort study of RA patients who underwent bariatric surgery at two large academic centers. We identified subjects who met the 1987 ACR RA criteria and had undergone Roux-en-Y gastric bypass (RYGB), laparoscopic adjustable gastric banding (LAGB), or sleeve gastrectomy (SG). We reviewed medical records to obtain anthropometrics, laboratory values, validated or clinical measures of RA disease activity, and medication use at baseline (prior to surgery), at 6 and 12 months post-surgery, and at most recent follow-up visit. RA disease activity was categorized as remission, low, moderate, or high based on clinical, laboratory, and validated measures as available. RA-related medications were disease-modifying antirheumatic drugs, non-steroidal anti-inflammatory drugs, and glucocorticoids. At each post-surgical visit, variables were compared to baseline using paired T-tests, Wilcoxon signed-rank tests, or Fisher’s exact tests.

Results: We identified 53 RA patients who underwent bariatric surgery (43 RYGB, 7 LAGB, and 3 SG). Mean age at surgery was 47.9 years (SD 10.5), 95% were female, and 81% were white. Mean RA duration at surgery was 8.6 years (SD 8.1), 51% were seropositive, and 40% had erosions. At baseline, mean BMI was 47.8 kg/m² (SD 7.7) and mean weight was 282.7 lbs (SD 53.2, Table). Twelve months post-surgery, subjects lost a mean of 90.4 lbs (SD 38.2), which corresponded to a loss of 70% (SD 24) of excess weight above normal BMI (P<0.0001). RA disease activity was significantly improved at all subsequent points compared to baseline (P<0.0001). At 12 months, only 6% had moderate or high RA disease activity, compared to 57% at baseline (P<0.0001). At most recent follow-up (mean 5.8 years [SD 3.2] after surgery), 74% were in remission compared to 26% at baseline (P<0.0001). At last follow-up, 28% were in remission and off all RA-related medications compared to only 2% at baseline (P=0.28). At 12 months, only 66% were on any RA-related medication, compared to 98% at baseline (P=0.33). Subjects had significantly lower erythrocyte sedimentation rate and C-reactive protein measures at all follow-up points compared to baseline (P<0.05).

Conclusion: This observational study is the first to report that RA disease activity, RA-related medication use, and inflammatory markers are significantly improved after substantial weight loss from bariatric surgery. Our study was limited by including chart review classification of disease activity and was retrospective. These results suggest that weight loss may be an important non-pharmacologic strategy to reduce RA disease activity.