title: Diabetes resolution and hyperinsulinaemia after metabolic Roux-en-Y gastric bypass.
abstract: The global prevalence of type 2 diabetes mellitus and impaired glucose metabolism continues to rise in conjunction with the pandemic of obesity. The metabolic Roux-en-Y gastric bypass operation offers the successful resolution of diabetes in addition to sustained weight loss and excellent long-term outcomes in morbidly obese individuals. The procedure consists of the physiological BRAVE effects: (i) Bile flow alteration; (ii) Reduction of gastric size; (iii) Anatomical gut rearrangement and altered flow of nutrients; (iv) Vagal manipulation and (v) Enteric gut hormone modulation. This operation provides anti-diabetic effects through decreasing insulin resistance and increasing the efficiency of insulin secretion. These metabolic outcomes are achieved through weight-independent and weight-dependent mechanisms. These include the foregut, midgut and hindgut mechanisms, decreased inflammation, fat, adipokine and bile metabolism, metabolic modulation, shifts in gut microbial composition and intestinal gluconeogenesis. In a small minority of patients, gastric bypass results in hyperinsulinaemic hypoglycaemia that may lead to nesidioblastosis (pancreatic beta-cell hypertrophy with islet hyperplasia). Elucidating the precise metabolic mechanisms of diabetes resolution and hyperinsulinaemia after surgery can lead to improved operations and disease-specific procedures including 'diabetes surgery'. It can also improve our understanding of diabetes pathogenesis that may provide novel strategies for the management of metabolic syndrome and impaired glucose metabolism.
authors.affiliation: The Department of Surgery and Cancer, Imperial College London, London, UK. h.ashrafian@imperial.ac.uk
authors.forename: H
authors.initials: H
authors.lastname: Ashrafian
authors.forename: T
authors.initials: T
authors.lastname: Athanasiou
authors.forename: J V
authors.initials: JV
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Bueter
authors.forename: K
authors.initials: K
authors.lastname: Ahmed
authors.forename: K
authors.initials: K
authors.lastname: Nagpal
authors.forename: E
authors.initials: E
authors.lastname: Holmes
authors.forename: A
authors.initials: A
authors.lastname: Darzi
authors.forename: S R
authors.initials: SR
authors.lastname: Bloom
mesh_terms: D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism / Q000601:surgery; D015390:Gastric Bypass; D006801:Humans; D006946:Hyperinsulinism / Q000378:metabolism / Q000601:surgery; D007328:Insulin / Q000097:blood / Q000378:metabolism; D024821:Metabolic Syndrome / Q000378:metabolism / Q000601:surgery*; D009767:Obesity, Morbid / Q000378:metabolism* / Q000601:surgery*
chemical_list: D001786:Blood Glucose; D007328:Insulin