Type 1 Diabetes Insulin Regimen
A 19-year-old man is newly diagnosed with type 1 diabetes after presenting with weight loss and ketonuria. He has recovered from diabetic ketoacidosis, is eating normally, and glutamic acid decarboxylase antibodies are positive. C-peptide is low and his body mass index is 21 kg/m². He wants flexible meal timing at university. Which insulin regimen is most appropriate?
- A.Glargine once daily plus mealtime insulin aspartCorrect
- B.NPH insulin twice daily as the only insulin
- C.Glargine and detemir once daily each
- D.Premixed 70/30 insulin once daily before breakfast
Explanation
Type 1 diabetes is absolute insulin deficiency, so replacement must reproduce both the continuous basal secretion that restrains hepatic glucose output overnight and between meals and the sharp prandial peaks that dispose of ingested carbohydrate. A basal-bolus regimen with a long-acting analogue such as glargine or degludec once daily plus a rapid-acting analogue such as aspart, lispro, or glulisine before each meal achieves this and is the recommended standard, with continuous subcutaneous insulin infusion as the alternative. Roughly half the total daily dose is given as basal and half distributed as prandial boluses matched to carbohydrate intake, which is precisely what allows a student to skip, delay, or enlarge meals without hypoglycaemia. Twice-daily NPH alone provides no meal coverage and its pronounced 4 to 8 hour peak causes mid-morning and nocturnal hypoglycaemia while leaving postprandial excursions untreated. Giving two different long-acting analogues together is pharmacologically illogical, duplicates basal action, and provides no bolus component. Premixed 70/30 insulin once daily locks the patient into fixed meal sizes and times, cannot be adjusted independently for basal and prandial needs, and is inadequate in type 1 diabetes. All patients need structured education in carbohydrate counting, dose adjustment, hypoglycaemia recognition, sick day rules, and glucose monitoring, ideally with continuous glucose monitoring, targeting an HbA1c below 7 percent with time in range above 70 percent.
Why each option
- A.
- Correct. A basal-bolus regimen of once-daily long-acting analogue plus rapid-acting analogue at meals physiologically replaces insulin and permits flexible eating.
- B.
- NPH twice daily alone gives no prandial coverage and its pronounced peak causes hypoglycaemia between meals and overnight.
- C.
- Two long-acting analogues duplicate basal coverage and supply no mealtime insulin, so postprandial glucose remains uncontrolled.
- D.
- Once-daily premixed insulin forces rigid meal timing and content and cannot cover a full day in type 1 diabetes.
Reference: American Diabetes Association Standards of Care in Diabetes, 2025
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