Diabetes Education Certification Blood Glucose Monitoring & Targets 2 — Questions and Answers
Question 1: A patient with type 2 diabetes on metformin only reports consistent fasting glucose values of 95–105 mg/dL but an A1C of 8.2%. What is the most likely explanation?
- The glucometer is calibrated incorrectly
- Postprandial glucose excursions are elevating the A1C (Correct answer)
- Fasting values alone are unreliable in type 2 diabetes
- Metformin artificially lowers fasting readings
Correct answer: Postprandial glucose excursions are elevating the A1C
A1C reflects average glucose over ~3 months, so high postprandial spikes can raise A1C even when fasting values appear normal.
Question 2: According to ADA standards, what is the recommended preprandial blood glucose target range for most non-pregnant adults with diabetes?
- 60–100 mg/dL
- 80–130 mg/dL (Correct answer)
- 100–150 mg/dL
- 70–120 mg/dL
Correct answer: 80–130 mg/dL
The ADA recommends a preprandial (before meal) plasma glucose target of 80–130 mg/dL for most non-pregnant adults.
Question 3: A continuous glucose monitor (CGM) displays a double-arrow trending downward. What action should a patient taking insulin be advised to take?
- Administer a correction dose of insulin
- Consume 15–20 g of fast-acting carbohydrate preemptively if below 90 mg/dL (Correct answer)
- Recalibrate the sensor immediately
- Wait 30 minutes and recheck
Correct answer: Consume 15–20 g of fast-acting carbohydrate preemptively if below 90 mg/dL
A rapid downward trend arrow indicates falling glucose; ADA guidance supports treating impending hypoglycemia with carbohydrates when trending down rapidly and approaching the low threshold.
Question 4: Which of the following factors can cause falsely LOW blood glucose readings on most home glucometers?
- High altitude
- Hematocrit below 30% (anemia)
- Hematocrit above 55% (polycythemia) (Correct answer)
- Vitamin C ingestion
Correct answer: Hematocrit above 55% (polycythemia)
High hematocrit (polycythemia) causes falsely low glucometer readings because red blood cells compete with the glucose reaction on the test strip.
Question 5: For a patient wearing a CGM, what is the minimum recommended 'Time in Range' (70–180 mg/dL) for most adults with type 1 or type 2 diabetes?
- 50%
- 60%
- 70% (Correct answer)
- 80%
Correct answer: 70%
International consensus recommends that most adults with diabetes achieve at least 70% time in range (70–180 mg/dL).
Question 6: A patient uses a flash glucose monitoring system and notices the sensor reading is 220 mg/dL but she feels fine. She checks a fingerstick and gets 178 mg/dL. Which value should guide her insulin dosing decision?
- The flash sensor value, as it is more recent
- The fingerstick value, as capillary blood is the reference standard (Correct answer)
- Average the two values
- Neither; recheck both in 15 minutes
Correct answer: The fingerstick value, as capillary blood is the reference standard
When sensor and fingerstick readings diverge significantly, the fingerstick capillary blood glucose is the reference standard for dosing decisions.
Question 7: Which postprandial blood glucose target does the ADA recommend for most non-pregnant adults, measured 1–2 hours after the start of a meal?
- Less than 140 mg/dL
- Less than 160 mg/dL
- Less than 180 mg/dL (Correct answer)
- Less than 200 mg/dL
Correct answer: Less than 180 mg/dL
The ADA recommends postprandial glucose less than 180 mg/dL (peak) for most non-pregnant adults with diabetes.
Diabetes Education Certification Blood Glucose Monitoring & Targets 2
A patient with type 2 diabetes on metformin only reports consistent fasting glucose values of 95–105 mg/dL but an A1C of 8.2%.
What is the most likely explanation?