GP · metabolic-and-endocrine-health
Type 2 diabetes
Also known as Type 2 diabetes mellitus · Non-insulin-dependent diabetes · Adult-onset diabetes
GP-fellowship guide to type 2 diabetes: the diagnostic thresholds and screening intervals, metformin-first stepwise escalation driven by comorbidity before HbA1c, the cardiovascular and renal outcome trials that reshaped drug selection (EMPA-REG, LEADER, CREDENCE, DAPA-HF, FLOW), insulin initiation, the annual complications screen, hyperglycaemic emergencies, hypoglycaemia and driving, and the DiRECT remission evidence.
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Red flags
- Hyperosmolar hyperglycemic state: plasma glucose above 600 mg/dL (33 mmol/L) with effective osmolality above 320 mOsm/kg and no ketosis carries a mortality of 10–20% — about ten times DKA — and kills older adults through dehydration and thrombosis, not acidosis
- Any patient on an SGLT2 inhibitor with nausea, vomiting or abdominal pain can have euglycaemic ketoacidosis with glucose below 14 mmol/L — check ketones regardless of the glucose reading and stop the drug
- A driver on insulin or a sulfonylurea reporting severe hypoglycaemia, or hypoglycaemia while driving, must stop driving and notify the licensing authority — this is a legal duty, not advice
- New-onset weight loss with osmotic symptoms in a lean adult may be type 1 diabetes or LADA, not type 2 — check ketones and antibodies before labelling
Overview
Type 2 diabetes is a progressive disorder defined by the combination of insulin resistance and progressive beta-cell failure, producing chronic hyperglycaemia and its microvascular, macrovascular and neuropathic complications. It accounts for around 90% of all diabetes. An estimated 13% of US adults have diabetes and 34.5% meet criteria for prediabetes; prevalence rises with age.[4]
The disease is usually detected by screening or incidentally years after onset, because hyperglycaemia is silent until complications appear. Early detection matters: simulation modelling of the ADDITION-Europe trial showed the intensity of glucose, blood pressure and cholesterol treatment after diagnosis is less important than the time of its initiation — a 3-year diagnostic delay forfeits a 29% relative reduction in cardiovascular risk that prompt treatment would have delivered.[5]
Management is a lifelong cycle of lifestyle foundation, metformin-based pharmacotherapy escalated on individualised HbA1c targets, comorbidity-driven cardiorenal protection, and annual complication surveillance. The landmark trials of the last decade shifted the treatment goal from glucose alone to organ protection: empagliflozin reduced cardiovascular death by 38%, liraglutide reduced it by 22%, and canagliflozin cut kidney-failure progression by a third — benefits that are independent of the drugs' glucose-lowering effect.[12][14][20]
References37ShowHide
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- [4]US Preventive Services Task Force, Davidson KW, Barry MJ, et al. Screening for Prediabetes and Type 2 Diabetes: US Preventive Services Task Force Recommendation Statement JAMA, 2021.PMID 34427594
- [5]Sussman JB, Hayward RA, Choi H, et al. Early Detection and Treatment of Type 2 Diabetes Reduce Cardiovascular Morbidity and Mortality: A Simulation of the Results of the ADDITION-Europe Trial Diabetes Care, 2015.PMID 25986661
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- [7]UK Prospective Diabetes Study (UKPDS) Group Effect of intensive blood-glucose control with metformin on complications in overweight patients with type 2 diabetes (UKPDS 34) Lancet, 1998.PMID 9742977
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