GLP-1 receptor agonist treatment improved fasting and postprandial lipidomic profile independently of diabetes and weight loss.

Treatment with glucagon-like peptide-1 receptor agonists (GLP-1RAs) reduces liver steatosis and cardiometabolic risk (CMR). Only few data are available on lipid metabolism and no information on the postprandial lipidomic profile. Thus, we investigated how exenatide treatment changes lipid metabolism and composition during fasting and after a meal tolerance test (MTT) in adults with severe obesity without diabetes. Thirty individuals (26F/4M, 30-60 years old, BMI>40 kg/m2, HbA1c=5.76%) were assigned (1:1) to diet with exenatide treatment (EXE, n=15, 10 µg twice-daily) or without treatment as control (CT, n=15) for 3 months. Fasting and postprandial lipidomic profile (by LC/MS-QTOF) and fatty acid metabolism (following a 6-hour MTT/tracer study) and composition (by GC/MS) were evaluated before and after treatment. Both groups had slight weight loss (EXE: -5.5% vs CT: -1.9%, p=0.052). During fasting, exenatide, compared to CT, reduced some ceramides (CER) and lysophosphocholines (LPC) previously associated with CMR, while relatively increasing unsaturated phospholipid species (PC, LPC) with protective effects on CMR, although concentrations of total lipid species were unchanged. During MTT, both groups suppressed lipolysis equally to baseline, but EXE exenatide significantly lowered free fatty acid clearance and postprandial triacyclglycerols (TAG) concentrations, particularly saturated TAGs with 44-54 carbons. Exenatide also reduced some postprandial CERs, PCs, LPCs previously linked to cardiometabolic risk. These changes in lipidomic profile remained statistically significant after adjusting for weight loss. Exenatide improved fasting and postprandial lipidomic profile associated with CMR mainly by reducing saturated postprandial TAGs and CERs, independently of weight loss and diabetes.

Dysglycemia Shapes Visceral Adipose Tissue's Response to GIP, GLP-1 and Glucagon in Individuals with Obesity.

Visceral adipose tissue (VAT) metabolic fingerprints differ according to body mass index (BMI) and glycemic status. Glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and glucagon are gut-associated hormones that play an important role in regulating energy and glucose homeostasis, although their metabolic actions in VAT are still poorly characterized. Our aim was to assess whether GLP-1, GIP and glucagon influence the VAT metabolite profile. To achieve this goal, VAT harvested during elective surgical procedures from individuals (N = 19) with different BMIs and glycemic statuses was stimulated with GLP-1, GIP or glucagon, and culture media was analyzed using proton nuclear magnetic resonance. In the VAT of individuals with obesity and prediabetes, GLP-1 shifted its metabolic profile by increasing alanine and lactate production while also decreasing isoleucine consumption, whereas GIP and glucagon decreased lactate and alanine production and increased pyruvate consumption. In summary, GLP-1, GIP and glucagon were shown to distinctively modulate the VAT metabolic profile depending on the subject's BMI and glycemic status. In VAT from patients with obesity and prediabetes, these hormones induced metabolic shifts toward gluconeogenesis suppression and oxidative phosphorylation enhancement, suggesting an overall improvement in AT mitochondrial function.

Visceral Adipose Tissue Displays Unique Metabolomic Fingerprints in Obesity, Pre-Diabetes and Type 2 Diabetes.

Visceral adipose tissue (VAT) metabolic profiling harbors the potential to disentangle molecular changes underlying obesity-related dysglycemia. In this study, the VAT exometabolome of subjects with obesity and different glycemic statuses are analyzed. The subjects (n = 19) are divided into groups according to body mass index and glycemic status: subjects with obesity and euglycemia (Ob+NGT, n = 5), subjects with obesity and pre-diabetes (Ob+Pre-T2D, n = 5), subjects with obesity and type 2 diabetes under metformin treatment (Ob+T2D, n = 5) and subjects without obesity and with euglycemia (Non-Ob, n = 4), used as controls. VATs are incubated in culture media and extracellular metabolite content is determined by proton nuclear magnetic resonance (1H-NMR). Glucose consumption is not different between the groups. Pyruvate and pyroglutamate consumption are significantly lower in all groups of subjects with obesity compared to Non-Ob, and significantly lower in Ob+Pre-T2D as compared to Ob+NGT. In contrast, isoleucine consumption is significantly higher in all groups of subjects with obesity, particularly in Ob+Pre-T2D, compared to Non-Ob. Acetate production is also significantly lower in Ob+Pre-T2D compared to Non-Ob. In sum, the VAT metabolic fingerprint is associated with pre-diabetes and characterized by higher isoleucine consumption, accompanied by lower acetate production and pyruvate and pyroglutamate consumption. We propose that glucose metabolism follows different fates within the VAT, depending on the individuals' health status.

Gut hormone release after gastric bypass depends on the length of the biliopancreatic limb.

BACKGROUND/OBJECTIVES: Changes in gut hormone secretion are important for the anti-diabetic effects of bariatric surgery. Roux-en-Y gastric bypass (RYGB) with extended biliopancreatic limb (BPL) length may improve the metabolic outcomes when compared to the classical procedure. The purpose of this study was to compare the gut hormone responses to a liquid mixed meal after RYGB with one of two different BPL lengths. SUBJECTS/METHODS: Non-diabetic weight-stable individuals previously submitted to classical RYGB (n = 9; BPL length: 87.8 ± 20.5 cm) or long BPL RYGB (n = 11; BPL length: 200 cm) underwent a liquid mixed-meal tolerance test (MMTT). Blood was sampled at baseline and 15, 30, 45, 60, 90 and 120 min later for measurement of plasma glucose, enteropancreatic hormones and total bile acids (TBA). RESULTS: Plasma glucose excursion curves were similar in the two groups. The long BPL RYGB group displayed significantly higher fasting and post-prandial GLP-1 (t = 0 min, p = 0.01 and t = 45 min, p < 0.05; tAUC: 11,205 ± 3399 vs 7889 ± 1686 pmol/L × min, p = 0.02) and neurotensin (t = 0 min, p = 0.02; t = 45 min, p < 0.05 and t = 60 min, p < 0.01; tAUC: 18,392 ± 7066 vs 11,437 ± 3658 pmol/L × min, p = 0.02) levels, while responses of GIP (t = 15 min, p < 0.01), insulin and C-peptide (t = 30 min, p < 0.001) were lower as compared to classical RYGB. There were no differences in glucagon, PP, PYY and TBA between the groups. CONCLUSIONS: RYGB with a longer BPL results in a distinctive post-prandial hormone profile with augmented GLP-1 and neurotensin responses that could be beneficial for the metabolic outcomes of the surgery.