Long-term safety and disease-modifying potential of metabolic and bariatric surgery in patients with systemic lupus erythematosus

Background: Obesity commonly coexists with systemic lupus erythematosus (SLE), exacerbating metabolic, cardiovascular, and renal complications. Metabolic and bariatric surgery (MBS) achieves durable weight loss and improves metabolic health, but its long-term safety and potential disease-modifying effects in SLE remain unclear. Methods: A multicenter, retrospective cohort study was conducted using the TriNetX global federated research network, comprising data from over 140 healthcare organizations between 2009 and 2024. Adults with SLE who underwent sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) were compared with propensity score-matched cohorts of non-SLE patients undergoing MBS and patients with SLE who do not undergo MBS. Primary outcomes included long-term nutritional and metabolic safety. Secondary outcomes evaluated changes in immunosuppressive medication use, inflammatory markers, renal function, and mortality over a five-year follow-up. Results: Among 123,219 MBS patients, 713 (0.6%) had SLE. After matching, patients with SLE had higher risks of vitamin D deficiency (53.8% vs 45.1%, p = 0.002) and hypoalbuminemia (9.7% vs 4.7%, p = 0.001), while mortality was comparable to patients without SLE. Within the SLE cohort, RYGB was associated with higher rates of ulcer, osteoporosis, and hypoalbuminemia compared with SG. Compared with matched patients with SLE who do not undergo MBS, MBS cohort was associated with reduced use of corticosteroids (32.9% vs 47.5%), immunosuppressants (9.1% vs 22.0%), and antimalarials (11.2% vs 28.1%), lower CRP and ESR levels, improved eGFR, and lower mortality (1.4% vs 4.4%, p = 0.001). Conclusions: In this large real-world study, MBS was associated with improved disease control, renal preservation, and reduced mortality in patients with SLE, though at the expense of greater nutritional risks—particularly after RYGB. Careful patient selection and long-term multidisciplinary follow-up are essential to optimize outcomes in this complex population.