[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Endocrine system](https://durgical.com/en/general-pathology/areas/endocrine/) › Type 2 diabetes # Type 2 diabetes - Mechanism In type 2 diabetes the body's cells stop listening to insulin, and over time the pancreas cannot keep up. Extra weight is the main driver. Updated Nov 12, 2026 ## Key points - Insulin resistance: reduced glucose uptake in muscle and fat, failure to suppress hepatic glucose output, increased lipolysis. - Obesity links: free fatty acids and lipid metabolites inhibit insulin signalling (serine phosphorylation of IRS); adipokines shift (less adiponectin); inflammation (IL-1, TNF). - Beta-cell failure: glucotoxicity, lipotoxicity, islet amyloid (amylin, IAPP), impaired incretin effect. - Genetics: polygenic; TCF7L2 is the strongest common locus; identical twin concordance is higher than in type 1. - PPAR-gamma agonists (thiazolidinediones) improve insulin sensitivity, illustrating the adipose link. - Acanthosis nigricans and PCOS are clinical markers of insulin resistance. ## What it is Type 2 diabetes results from two defects: insulin resistance, mostly from central obesity, and beta-cell dysfunction that fails to compensate. Genetics matter, as shown by high concordance in identical twins and many risk loci, but environmental factors, mainly excess calories and inactivity, decide who gets it. It accounts for the great majority of diabetes worldwide and in Latin America. ## Structure - Islets: deposition of amyloid (from islet amyloid polypeptide) in the islet capillaries and between cells. - Modest reduction of beta-cell mass, less than in type 1. - Liver: steatosis (MASLD) is common. ## Step by step - Central adipose tissue expands and releases more free fatty acids and pro-inflammatory cytokines, less adiponectin. - In muscle and liver, lipid metabolites and inflammatory kinases impair insulin receptor signalling (IRS serine phosphorylation). - Muscle takes up less glucose; the liver keeps making glucose: blood glucose rises. - Beta cells compensate with hyperinsulinaemia for years. - Under chronic glucose and fat excess, with amyloid deposition and genetic weakness, beta cells fail: overt diabetes. ## Clinical notes - Often asymptomatic for years; found by screening or by complications. - Rising in adolescents with obesity. - Weight loss and exercise improve insulin sensitivity; metabolic surgery can induce remission. ## Memory aid Type 2 is a tug of war: fat pulls against insulin for years while the beta cell pulls harder, until amyloid ties its hands. ## Test yourself Think of the answer, then tap the question to see it. ## How do free fatty acids cause insulin resistance? Their metabolites activate kinases that phosphorylate IRS proteins on serine residues, weakening insulin receptor signalling. ## What is deposited in the islets in type 2 diabetes? Amyloid derived from islet amyloid polypeptide (amylin). ## Which adipokine improves insulin sensitivity and falls in obesity? Adiponectin. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/general-pathology/type-2-diabetes/) [More Pathology questions →](https://durgical.com/en/practice/?f=pathology) ## Elsewhere in DurgiPedia - [Obesity: leptin, adipokines and its consequences](https://durgical.com/en/general-pathology/obesity-leptin-adipokines-and-its-consequences/) - [Insulin signalling](https://durgical.com/en/biochemistry/topics/insulin-signalling/) - [Insulin receptor](https://durgical.com/en/biochemistry/enzymes/insulin-receptor/) - [Islets and insulin: secretion and actions](https://durgical.com/en/physiology/islets-and-insulin-secretion-and-actions/) ## Connections ## Related 6 - [Diabetes mellitus: diagnosis and classification](https://durgical.com/en/general-pathology/diabetes-mellitus-diagnosis-and-classification/) - [Type 1 diabetes](https://durgical.com/en/general-pathology/type-1-diabetes/) - [Diabetes: how hyperglycaemia damages tissue](https://durgical.com/en/general-pathology/diabetes-how-hyperglycaemia-damages-tissue/) - [Metabolic steatotic liver disease (MASLD, MASH)](https://durgical.com/en/general-pathology/metabolic-steatotic-liver-disease/) - [Obesity: leptin, adipokines and its consequences](https://durgical.com/en/general-pathology/obesity-leptin-adipokines-and-its-consequences/) - [Benign epidermal growths](https://durgical.com/en/general-pathology/benign-epidermal-growths/) ## Related conditions 7 - [Type 2 diabetes mellitus](https://durgical.com/en/conditions/type-2-diabetes-mellitus/) - [Obesity](https://durgical.com/en/conditions/obesity/) - [Metabolic syndrome](https://durgical.com/en/conditions/metabolic-syndrome/) - [Metabolic dysfunction-associated steatotic liver disease (MASLD/NAFLD)](https://durgical.com/en/conditions/metabolic-dysfunction-associated-steatotic-liver-disease/) - [Polycystic ovary syndrome](https://durgical.com/en/conditions/polycystic-ovary-syndrome/) - [Acanthosis nigricans](https://durgical.com/en/conditions/acanthosis-nigricans/) - [Gestational diabetes mellitus](https://durgical.com/en/conditions/gestational-diabetes-mellitus/) [← All of general pathology](https://durgical.com/en/general-pathology/) Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given. Sources: [Diabetes Type 2](https://medlineplus.gov/diabetestype2.html) (MedlinePlus, US National Library of Medicine, 2025); [Type 2 diabetes](https://medlineplus.gov/genetics/condition/type-2-diabetes/) (MedlinePlus, US National Library of Medicine, 2025). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/general-pathology/type-2-diabetes/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/type-2-diabetes/