Baseline Abdominal Lipid Partitioning Is Associated with the Metabolic Response to Bariatric Surgery

Background: The purpose of this study was to compare the effects of two bariatric procedures on abdominal lipid partitioning and metabolic response. Methods: Fifty-one patients (RYGB 31(11 M/20 F); (SG) 20(8 M/12 F)) who met the criteria of metabolic syndrome before the operation were followed following Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG). Visceral and subcutaneous abdominal fat depots were assessed by CT before, 6 months, and 12 months following the operation. Results: Patients undergoing both procedures did not differ in baseline body mass index (BMI) (42.84 ± 4.65 vs. 41.70 ± 4.68 kg/m²) or abdominal lipid depots. BMI at 12 months post-op was similar (29.44 ± 3.35 vs 30.86 ± 4.31 kg/m² for RYGB and SG, respectively). Both procedures led to a significant reduction in visceral and subcutaneous fat at 6 months (p < 0.001 for both). The visceral-to-subcutaneous fat ratio was comparable at 6 months vs. baseline yet was lower at 12 months vs. baseline for both procedures (p < 0.01). In patients who lost the diagnosis of metabolic syndrome, baseline visceral/subcutaneous fat was the only predictor of recovery (p < 0.005). No difference was detected between procedures in dynamics of abdominal fat depots or remission of cardiovascular risk factors. Conclusions: RYGB and SG induce a similar effect on abdominal fat mobilization. The metabolic effects in individual patients are mostly determined by their baseline abdominal lipid partitioning.