Bariatric Surgery and Its Metabolic Effects in Obese Patients with Type 2 Diabetes

Nyakairu Doreen G.

 

Faculty of Science and Technology Kampala International University Uganda

ABSTRACT

Bariatric/metabolic surgery is the most effective intervention for achieving substantial and durable weight loss in people with obesity and has profound, often rapid, effects on glycemic control in type 2 diabetes (T2D). Beyond calorie restriction and weight loss, procedures such as Roux‑en‑Y gastric bypass (RYGB), sleeve gastrectomy (SG), biliopancreatic diversion with duodenal switch (BPD‑DS), and one‑anastomosis gastric bypass (OAGB) remodel entero‑insular signaling, bile‑acid–FXR/TGR5 pathways, gut–brain–liver circuits, and the microbiome. These weight‑independent mechanisms amplify insulin sensitivity, enhance β‑cell function, and promote diabetes remission in a sizable subset of patients. Surgery also improves comorbidities—non‑alcoholic fatty liver disease, obstructive sleep apnea, hypertension, dyslipidemia—and reduces incident cardiovascular events and mortality. However, benefits vary with procedure type, baseline β‑cell reserve, diabetes duration, and adherence to postoperative nutrition and follow‑up. Risks include peri‑operative complications, micronutrient deficiencies, hypoglycemia, nephrolithiasis, alcohol use disorder, bone loss, and weight regain in a minority; careful selection, team‑based peri‑operative care, and long‑term surveillance mitigate these. As potent anti‑obesity/anti‑diabetic pharmacotherapies (e.g., GLP‑1 receptor agonists and multi‑agonists) expand options, surgery retains a unique role when severe obesity, refractory hyperglycemia, or complications necessitate rapid, durable metabolic change. This review synthesizes mechanisms of glucose improvement after surgery; compares procedures and outcomes; summarizes effects on end organs; details peri‑operative management; and proposes an integrated, precision framework that aligns surgical choice with phenotypes and uses adjunct lifestyle and pharmacotherapy to extend remission while minimizing risks.

Keywords: metabolic surgery; Roux‑en‑Y gastric bypass; sleeve gastrectomy; bile acids/incretins; diabetes remission

 

CITE AS: Nyakairu Doreen G. (2026). Bariatric Surgery and Its Metabolic Effects in Obese Patients with Type 2 Diabetes. IDOSR JOURNAL OF BIOLOGY, CHEMISTRY AND PHARMACY 11(1):78-84. https://doi.org/10.59298/IDOSR/JBCP/26/102.7884