June 27, 2003
Diagnosis and Symptoms
Question from a dietitian in Brooklyn, New York, USA:
I currently seeing a 35 year old healthy black woman who was recently diagnosed with type 2 diabetes by her primary care physician. She complained of fatigue but no other symptoms, and the family history shows only a maternal grandmother with diabetes. She exercises avidly and has had two sets of labs (six weeks apart) with dietary intervention between the two:
TEST
FIRST SET
SECOND SET
Fasting Blood Glucose
190 mg/dl [10.6 mmol/L]
163 mg/dl [9.1 mmol/L]
A1c
6.8%
6.3%
GAD-65 antibody
—
<1.0
C-peptide
---
1.0
The doctor's recommendation is to start oral medications, but I am wondering if she really has type 2 diabetes as he suspects. Are there other tests she should have? Are there certain medications that might work better than others?
Answer:
The American Diabetes Association defines diabetes as two venous fasting glucose levels greater than 126 mg/dl [7 mmol/L], so. on the basis of the described fasting glucose levels, she has diabetes. The hemoglobin A1c is elevated, but this is not a sensitive test for diabetes. The labs are also consistent with type 2 diabetes. Her anti-GAD 65 antibody is negative and the C-peptide is not unmeasurable.
My usual recommendation would be to start with metformin because of its ability to normalize the glucose at this level of hyperglycemia without hypoglycemia. In addition, this medication is not associated with weight gain, unlike the other oral hypoglycemic agents.
JTL
