Which of the following laboratory findings is characteristic of type 1 diabetes mellitus
Question : Which of the following laboratory findings is characteristic of type 1 diabetes mellitus?
A. Elevated fasting blood glucose >7.0 mmol/L
B. Positive islet autoantibodies (e.g., GADAb, ICA)
C. Elevated glycated hemoglobin (HbA1c) >6.5%
D. Impaired glucose tolerance in oral glucose tolerance test (OGTT)
Answer: B
Explanation: Type 1 diabetes is an autoimmune disease characterized by the destruction of pancreatic β-cells, so islet autoantibodies (such as glutamic acid decarboxylase antibody GADAb, islet cell antibody ICA) are positive, which is a characteristic finding. Elevated fasting blood glucose, elevated HbA1c, and impaired glucose tolerance are common diagnostic criteria for diabetes but are not specific to type 1 diabetes and can also be seen in type 2 diabetes. Hence, the correct answer is B.
