Impact of prior bariatric surgery on outcomes of hospitalized patients with systemic lupus erythematosus: a propensity score-matched analysis of the U.S. nationwide inpatient sample.

Background: Systemic lupus erythematosus (SLE) is an autoimmune disease that primarily affects young women, has many different manifestations, and the disease severity can wax and wane.

Objectives: This study aims to determine the association between prior bariatric surgery and SLE outcomes.

Setting: A population-based, retrospective study using data from the U.S. Nationwide Inpatient Sample (NIS) database between 2005 and 2018.

Methods: Data of hospitalized patients with SLE and morbid obesity were extracted. Exclusion criteria were age <18 years and missing information on mortality. Patients were separated into 2 groups: with or without prior bariatric surgery. One: 4 propensity score matching (PSM) were performed to balance the characteristics between the groups. Associations between prior bariatric surgery and inpatient outcomes were determined by logistic regressions.

Results: A total of 38,286 hospitalized patients with SLE and morbid obesity were identified. After exclusions and PSM, there remained 9050 subjects in the study sample (with prior bariatric surgery: 1810; without prior bariatric surgery: 7240), representing 44,952 U.S. inpatients. After adjusting for confounders in multivariable analysis, prior bariatric surgery was significantly associated with lower odds for prolonged length of stay (LOS), unfavorable discharge, and SLE-related complications. Specifically, prior bariatric surgery was significantly associated with lower risks of acute myocardial infarction (AMI)/stroke (aOR = .44, 95% CI: .30-.65), venous thromboembolism (VTE) (aOR = .74, 95% CI: .57-.96), pneumonia (aOR = .60, 95% CI: .47-.76), sepsis (aOR = .62, 95% CI: .51-.75), acute and chronic glomerulonephritis (aOR = .53, 95% CI: .38-.76), acute kidney injury (AKI) (aOR = .64, 95% CI: .52-.77), and anemia (aOR = .77, 95% CI: .68-.87).

Conclusions: Prior bariatric surgery is associated with favorable in-hospital outcomes in hospitalized patients with SLE and decreased likelihood for several SLE-related complications.