OGT Glucose Values and Reference Ranges 1 — Questions and Answers
Question 1: According to ADA criteria, what is the 2-hour plasma glucose value that confirms diabetes during an OGTT?
- ≥140 mg/dL
- ≥180 mg/dL
- ≥200 mg/dL (Correct answer)
- ≥250 mg/dL
Correct answer: ≥200 mg/dL
A 2-hour plasma glucose of ≥200 mg/dL during a 75 g OGTT confirms a diagnosis of diabetes mellitus per ADA guidelines.
Question 2: What 2-hour OGTT value indicates impaired glucose tolerance (prediabetes)?
- <100 mg/dL
- 100–125 mg/dL
- 140–199 mg/dL (Correct answer)
- ≥200 mg/dL
Correct answer: 140–199 mg/dL
A 2-hour glucose of 140–199 mg/dL is classified as impaired glucose tolerance, a prediabetes category.
Question 3: A fasting plasma glucose below which value is considered normal on an OGTT?
- <70 mg/dL
- <100 mg/dL (Correct answer)
- <110 mg/dL
- <126 mg/dL
Correct answer: <100 mg/dL
A fasting plasma glucose below 100 mg/dL is considered normal according to current ADA diagnostic criteria.
Question 4: What fasting glucose level at the start of an OGTT indicates impaired fasting glucose (IFG)?
- 70–99 mg/dL
- 100–125 mg/dL (Correct answer)
- 126–139 mg/dL
- ≥140 mg/dL
Correct answer: 100–125 mg/dL
Impaired fasting glucose is defined as a fasting plasma glucose of 100–125 mg/dL, indicating prediabetes.
Question 5: Which unit is standardly used to report plasma glucose in US OGTT results?
- mmol/L
- mg/dL (Correct answer)
- mEq/L
- g/dL
Correct answer: mg/dL
In the United States, plasma glucose is standardly reported in milligrams per deciliter (mg/dL).
Question 6: A 2-hour glucose of 138 mg/dL on a standard OGTT would be categorized as:
- Normal (Correct answer)
- Impaired glucose tolerance
- Diabetes
- Hypoglycemia
Correct answer: Normal
A 2-hour glucose below 140 mg/dL is considered a normal OGTT result, ruling out impaired glucose tolerance and diabetes.
OGT Glucose Values and Reference Ranges 1
According to ADA criteria, what is the 2-hour plasma glucose value that confirms diabetes during an OGTT?