OGT Glucose Values and Reference Ranges 2 — Questions and Answers
Question 1: Which fasting glucose level during OGTT confirms diabetes without further testing?
- ≥100 mg/dL
- ≥110 mg/dL
- ≥126 mg/dL (Correct answer)
- ≥140 mg/dL
Correct answer: ≥126 mg/dL
A fasting plasma glucose of ≥126 mg/dL, confirmed on a repeat test, meets ADA criteria for diabetes diagnosis.
Question 2: What plasma glucose value defines reactive hypoglycemia during an extended OGTT?
- <70 mg/dL within 4 hours of glucose load (Correct answer)
- <100 mg/dL at 2 hours
- <110 mg/dL at 3 hours
- <80 mg/dL at 1 hour
Correct answer: <70 mg/dL within 4 hours of glucose load
Reactive hypoglycemia is diagnosed when plasma glucose drops below 70 mg/dL within 4 hours of glucose ingestion during an extended OGTT.
Question 3: In which unit does the WHO express glucose values when reporting OGTT results internationally?
- mg/dL
- mmol/L (Correct answer)
- mg/L
- g/dL
Correct answer: mmol/L
The World Health Organization reports glucose in mmol/L, which is the standard in most countries outside the United States.
Question 4: A 1-hour plasma glucose of 209 mg/dL during a 75 g OGTT in a non-pregnant adult is:
- Diagnostic of diabetes on its own
- Consistent with normal glucose tolerance
- A standalone criterion for impaired glucose tolerance
- Used in combination with fasting and 2-hour values for diagnosis (Correct answer)
Correct answer: Used in combination with fasting and 2-hour values for diagnosis
For non-pregnant adults, the 1-hour glucose value alone is not a standalone diagnostic criterion; it is interpreted alongside fasting and 2-hour values.
Question 5: What is the normal 2-hour plasma glucose value during an OGTT?
- <100 mg/dL
- <120 mg/dL
- <140 mg/dL (Correct answer)
- <160 mg/dL
Correct answer: <140 mg/dL
A 2-hour plasma glucose below 140 mg/dL is considered a normal result on a standard OGTT.
Question 6: Which of the following best describes the term 'glucose tolerance'?
- The amount of glucose a patient can drink
- The body's ability to regulate blood glucose after a carbohydrate load (Correct answer)
- The rate at which glucose is absorbed by the intestine
- The kidney threshold for glucose excretion
Correct answer: The body's ability to regulate blood glucose after a carbohydrate load
Glucose tolerance refers to the body's capacity to metabolize and return blood glucose to normal levels following a glucose challenge.
OGT Glucose Values and Reference Ranges 2
Which fasting glucose level during OGTT confirms diabetes without further testing?