Comprehensive Assessment of the Effects of Sleeve Gastrectomy on Glucose, Lipid, and Amino Acid Metabolism in Asian Individuals with Morbid Obesity

Obesity-induced insulin resistance leads to abnormalities in glucose, lipid, and amino acid metabolism. Our study examined the differences in insulin-mediated glucose, amino acid, and lipid metabolism between morbidly obese subjects with non-obese controls and the associated changes following sleeve gastrectomy (SG). Non-obese controls and individuals with morbid obesity and scheduled for SG were recruited. Metabolic assessments were performed for all subjects at baseline and at 6 months after SG for eight subjects. The hyperinsulinemic-euglycemic clamp technique together with comprehensive metabolomic profiling was used to quantify insulin-mediated glucose, amino acid, and lipid metabolism. Eleven morbidly obese non-diabetic subjects scheduled for SG and nine non-obese controls were recruited. Compared to controls, obese subjects had significantly lower glucose uptake (4.4 ± 0.6 vs. 17.3 ± 2.4 mg/kg FFM/min per μU/mL·100) and higher concentration of branched-chain amino acids (BCAAs, 332.5 ± 26.8 vs. 235.3 ± 11.0 μM), non-esterified fatty acid (52.9 ± 9.9 vs. 25.6 ± 6.7 μM), and lipid-related acylcarnitines (intermediate chain 389.8 ± 32.5 vs. 285.9 ± 20.5; long chain 301.7 ± 22.1 vs. 236.0 ± 13.3 nM) during insulin clamp. Body weight significantly reduced at 6 months after bariatric surgery (92.5 ± 6.3 vs. 115.2 ± 6.9 kg), together with improvements in insulin-mediated glucose uptake, and suppression of BCAAs, non-esterified fatty acids, and lipid-related metabolites. Morbid obesity in Asian individuals was associated with impairment in the regulatory actions of insulin on glucose, amino acid, and lipid metabolism, and these obesity-induced regulatory dysfunctions improved significantly 6 months after SG.