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Nocturnal hypoglycaemia — SCE Endocrinology MCQ

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ModerateDiabetesNocturnal hypoglycaemiaSCE Endocrinology

A 46-year-old man with type 1 diabetes has early-morning hyperglycaemia. Continuous glucose monitoring shows glucose falling to 3.2 mmol/L at 03:00, then rising to 13 mmol/L by breakfast. What is the most likely explanation?

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Correct answer: A — Nocturnal hypoglycaemia with rebound hyperglycaemia

The CGM pattern shows nocturnal hypoglycaemia followed by rebound hyperglycaemia, classically described as a Somogyi-type pattern. Dawn phenomenon causes early-morning rise without preceding hypoglycaemia. The practical point is that increasing basal insulin would worsen the overnight nadir.

Reference: https://www.nice.org.uk/guidance/conditions-and-diseases/diabetes-and-other-endocrinal-nutritional-and-metabolic-conditions