Question

what lab marker is used to monitor diabetic patients who may be secretly taking insulin?
a) fasting glucose
b) c - peptide
c) hgba1c
d) fructosamine

Explanation:

• Fasting glucose: Measures glucose at a single time point, not specific to insulin use detection.
• C - peptide: When insulin is secreted endogenously (by the body's own pancreas), C - peptide is co - secreted. If a patient is taking exogenous (secretly taken) insulin, which does not contain C - peptide, low C - peptide levels would indicate lack of endogenous insulin production (since they are taking external insulin).
• HgbA1c: Reflects average blood glucose over 2 - 3 months, not specific to insulin source (endogenous or exogenous).
• Fructosamine: Reflects short - term (2 - 3 weeks) glycemic control, not specific to insulin source.

Answer:

B. C - peptide