Type 1 Diabetes Mellitus — UKMLA MCQ

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MediumEndocrinologyType 1 Diabetes MellitusUKMLA MRCGP AKT PARA MRCEM SBA MRCP Part 1 PSA

A 29-year-old woman presents with a 2-week history of fatigue, polyuria, and polydipsia. Her random plasma glucose is 18.5 mmol/L. Urine dipstick shows 4+ glucose and 2+ ketones. Her BMI is 24 kg/m². What is the most likely diagnosis?

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Correct answer: B — Type 1 Diabetes Mellitus

The presentation with osmotic symptoms (polyuria, polydipsia), fatigue, significant hyperglycaemia, and ketonuria in a young adult (under 30-40) with normal BMI strongly suggests Type 1 Diabetes Mellitus (T1DM), likely presenting in diabetic ketoacidosis (DKA) or impending DKA. While Type 2 diabetes can occur in younger people, significant ketonuria is much more characteristic of T1DM due to absolute insulin deficiency. Diabetes insipidus causes polyuria/polydipsia but without hyperglycaemia. Gestational diabetes occurs during pregnancy. MODY is possible but classic T1DM presentation is more likely given the ketones. Urgent assessment and management for potential DKA are required.

Reference: CKS: Diabetes - type 1