First-Phase Insulin Secretion Restoration and Differential Response to Glucose Load Depending on the Route of Administration in Type 2 Diabetic Subjects After Bariatric Surgery

• Published in: Diabetes care Vol. 32; no. 3; pp. 375 - 380
• Main Authors: Salinari, Serenella, Bertuzzi, Alessandro, Asnaghi, Simone, Guidone, Caterina, Manco, Melania, Mingrone, Geltrude
• Format: Journal Article
• Language: English
• Published: Alexandria, VA American Diabetes Association 01.03.2009
• Subjects: Adult; Bariatric Surgery; Biological and medical sciences; Care and treatment; Changes; Clinical Care/Education/Nutrition/Psychosocial Research; Complications and side effects; Development and progression; Diabetes; Diabetes Mellitus, Type 2 - metabolism; Diabetes Mellitus, Type 2 - surgery; Diabetes. Impaired glucose tolerance; Drug Administration Routes; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Female; Gastric Inhibitory Polypeptide - metabolism; Gastrointestinal surgery; glucagon-like peptide 1; Glucagon-Like Peptide 1 - metabolism; glucose; Glucose - metabolism; glucose tolerance; Glucose Tolerance Test; Humans; Insulin; Insulin - metabolism; Insulin resistance; Insulin Secretion; intravenous injection; Male; Medical sciences; Metabolic diseases; Middle Aged; Miscellaneous; Models, Theoretical; noninsulin-dependent diabetes mellitus; Obesity; Parenteral nutrition; Plasma; polypeptides; Public health. Hygiene; Public health. Hygiene-occupational medicine; Risk factors; Surgery; Type 2 diabetes; Veins & arteries; Italy; Endocrinopathy; Type 2 diabetes; Human; Pancreatic hormone; Phase; Nutrition; Secretion; Bariatric surgery; Metabolic diseases; Glucose tolerance test; Route of administration; Insulin; Restoration; Endocrinology
• ISSN: 0149-5992; 1935-5548; 1935-5548
• DOI: 10.2337/dc08-1314

OBJECTIVE:--The purpose of this study was to elucidate the mechanisms of diabetes reversibility after malabsorptive bariatric surgery. RESEARCH DESIGN AND METHODS--Peripheral insulin sensitivity and β-cell function after either intravenous (IVGTT) or oral glucose tolerance (OGTT) tests and minimal model analysis were assessed in nine obese, type 2 diabetic subjects before and 1 month after biliopancreatic diversion and compared with those in six normal-weight control subjects. Insulin-dependent whole-body glucose disposal was measured by the euglycemic clamp, and glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) were also measured. RESULTS:--The first phase of insulin secretion after the IVGTT was fully normalized after the operation. The disposition index from OGTT data was increased about 10-fold and became similar to the values found in control subjects, and the disposition index from IVGTT data increased about 3.5-fold, similarly to what happened after the euglycemic clamp. The area under the curve (AUC) for GIP decreased about four times (from 3,000 ± 816 to 577 ± 155 pmol · l⁻¹ · min, P < 0.05). On the contrary, the AUC for GLP1 almost tripled (from 150.4 ± 24.4 to 424.4 ± 64.3 pmol · l⁻¹ · min, P < 0.001). No significant correlation was found between GIP or GLP1 percent changes and modification of the sensitivity indexes independently of the route of glucose administration. CONCLUSIONS:--Restoration of the first-phase insulin secretion and normalization of insulin sensitivity in type 2 diabetic subjects after malabsorptive bariatric surgery seem to be related to the reduction of the effect of some intestinal factor(s) resulting from intestinal bypass.