Dipeptidyl peptidase-4 activity, lipopolysaccharide, C-reactive protein, glucose metabolism, and gut peptides 3 months after bariatric surgery

BACKGROUND: Bariatric surgery induces weight loss, but changes in glucose metabolism, gut peptides, and inflammatory biomarkers still have conflicting results. SETTINGS: University hospital. OBJECTIVES: We investigated glucose metabolism, gut hormones, and inflammatory profile after bariatric surgery and medical treatment. METHODS: Forty patients with obesity were recruited and were subjected to Roux-en-Y gastric bypass (n = 15; Bariatric Surgery Group - BSG) or received medical care (n = 20; MG). Sleeve gastrectomy was performed in five patients who were excluded from analysis. Glucose, insulin, homeostatic model for the assessment of insulin resistance (HOMA-IR), glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), glucagon, ghrelin, dipeptidyl peptidase-4 (DPP-4) activity, circulating lipopolysaccharide (LPS), LPS-binding protein (LPB) and high-sensitivity C-reactive protein (hs-CRP) were evaluated before and three months after each treatment. Except for HOMA-IR, hs-CRP, and LBP, all variables were assessed at fasting and 30- and 60-minutes after a standard meal. RESULTS: After 3 months, both groups lost weight. However, BSG had a more extensive reduction than MG (respectively, 17.6% vs. 4.25%; P < 0.01). Except for LPS levels, higher on BSG than MG (1.38 ± 0.96 vs. 0.83 ± 0.60 EU/ml, P < 0.01), groups were similar before treatment. In respect to metabolic/hormonal changes, the BSG showed higher glucose, insulin, GLP-1, and GIP levels at 30-min and also GLP-1 at 30- and 60-minutes. DPP-4 activity, HOMA-IR, and fasting LBP did not change. LPS levels at 60-minutes decreased after surgery in the BSG. hs-CRP decreased on BSG compared to MG. CONCLUSIONS: Bariatric surgery resulted in more extensive effects on glucose metabolism, gut hormones, and inflammation.