Bariatric Conversion Surgery Impact on LDL Cholesterol in Patients Previously Treated with Sleeve Gastrectomy

Background/Objectives: Many patients with obesity require conversion bariatric surgery (CBS) after sleeve gastrectomy (SG). The objective of this study was to assess the evolution of LDL cholesterol and other cardiometabolic parameters in patients who have undergone an SG and require a CBS, as the metabolic effects of such conversion procedures remain insufficiently understood. Methods: A retrospective analysis was conducted in a non-randomized prospective cohort of patients with severe obesity who were previously treated with SG and undergoing CBS. Changes in LDL cholesterol levels after SG were compared to those following CBS using repeated-measures ANOVA. Results: Twenty-eight patients were included (mean age 44.5 ± 7.2 years; 68% female; mean BMI 47.3 ± 7.2 kg/m²). Of these, 57% underwent Roux-en-Y gastric bypass (RYGB), and 43% underwent single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) as conversion procedures. The mean time between SG and CBS was 93.5 ± 45.3 months for RYGB and 31.0 ± 45.2 months for SADI-S. The change in LDL cholesterol pre- vs. post-SG was 3.3 mg/dL (95% CI: -13.6 to 20.1), whereas the change pre- vs. post-CBS was -25.7 mg/dL (95% CI: -37.5 to -13.9) (p < 0.001). Remission of high LDL-C was 18.8% after SG and 73.3% after CBS (p = 0.023). The cardiometabolic profile showed a marked improvement profile during the SG period, followed by maintenance of these improvements during the CBS period. Conclusions: CBS (with either RYGB or SADI-S) results in a reduction in LDL-C, in contrast to the initial surgery with SG. However, CBS does not appear to provide additional benefits over SG in terms of other cardiometabolic parameters.