Changes in use and hospital outcomes of bariatric surgery in Spain (2016-2022): analysis of the role of type 2 diabetes using propensity score matching.

Introduction: The objectives of this study were to examine temporal trends in the incidence of bariatric surgery (Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG)) in patients with and without type 2 diabetes mellitus (T2DM). Outcomes of hospitalization and the impact of T2DM on these outcomes were also analyzed.

Research design and methods: We performed an observational study with the Spanish national hospital discharge database. Obese patients with and without T2DM who underwent RYGB and SG between 2016 and 2022 were identified. Propensity score matching (PSM) and logistic regression were used to compare patients with and without T2DM and to evaluate the effect of T2DM and other variables on outcomes of surgery. A variable "severity" was created to cover patients who died in hospital or were admitted to the intensive care unit (ICU).

Results: A total of 32,176 bariatric surgery interventions were performed (28.86% with T2DM). 31.57% of RYGBs and 25.53% of SG patients had T2DM. The incidence of RYGB and SG increased significantly between 2016 and 2022 (p<0.001), with a higher incidence in those with T2DM than in those without (incidence rate ratio 4.07 (95% CI 3.95 to 4.20) for RYGB and 3.02 (95% CI 2.92 to 3.14) for SG). In patients who underwent SG, admission to the ICU and severity were significantly more frequent in patients with T2DM than in those without (both p<0.001). In the multivariate analysis, having T2DM was associated with more frequent severity in those who received SG (OR 1.23; 95% CI 1.07 to 1.42).

Conclusions: Between 2016 and 2022, bariatric surgery procedures performed in Spain increased in patients with and without T2DM. More interventions were performed on patients with T2DM than on patients without T2DM. RYGB was the most common procedure in patients with T2DM. The presence of T2DM was associated with more severity after SG.