Distinguishing between type 1 and type 2 diabetes
Alexandra E. Butler, David Misselbrook
Abstract
### What you need to know A 33 year old man with no notable medical history attends his general practitioner reporting two months of fatigue, with no other symptoms. His mother has hypothyroidism. His body mass index is 25 kg/m2 and he has a pulse rate of 72 beats/min and blood pressure 135/88 mmHg with no postural drop. Examination is unremarkable. A random blood glucose test shows 14 mmol/L (250 mg/dL). Urinalysis is normal. The next day the patient returns, and a repeat fasting glucose test finds 14 mmol/L . This article is intended to help primary care doctors to differentiate between type 1 and type 2 diabetes when first diagnosing diabetes in a patient where the distinction is unclear. For people who fit the classic pattern of type 2 diabetes (table 1), and where two glucose test results are in the diabetic range (box 1), no further testing is required for diagnosis, and management should follow current guidelines.1 Follow-up testing of glycated haemoglobin (HbA1c) is useful to assess glycaemia over time and to tailor treatment.1 View this table: Table 1 Clinical features at presentation that help to distinguish type 1 and type 2 diabetes Box 1 ### Criteria for the diagnosis of diabetes (all types) as determined by the World Health Organization and the American Diabetes Association17RETURN TO TEXT