Ambulatory glucose profile in a patient with type 1 diabetes and deferred insulin treatment

In August 2020 a 27-year-old male was admitted to an outpatient diabetes clinic with newonset diabetes mellitus.Before the visit, the patient was on 1500 mg of metformin for several days.His random blood glucose was 18.3 mmol/l, fasting glucose 17.0 mmol/l (reference range, 3.9-5.6mmol/l), HbA1c 10.8% (94.5 mmol/mol).The patient presented with polyuria and polydipsia, but no significant weight loss or ketoacidosis.The patient received education and was prescribed mealtime glulisine and glargine U300 once daily with an appropriate dosage guide.A two-week follow-up visit was scheduled, with laboratory tests and further educational sessions.The patient missed the appointment.In April 2024 he made a new appointment in the diabetes clinic.For almost 4 years he did not take insulin or any other diabetes medications.He intermittently used a continuous glucose monitoring device (CGM, FreeStyle Libre 2) and observed an average glucose of