OGT Glucose Values and Reference Ranges

Question 1

According to ADA criteria, what is the 2-hour plasma glucose value that confirms diabetes during an OGTT?

Accepted Answer

≥200 mg/dL

Answer

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)?

Accepted Answer

140–199 mg/dL

Answer

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?

Accepted Answer

<100 mg/dL

Answer

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)?

Accepted Answer

100–125 mg/dL

Answer

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?

Accepted Answer

mg/dL

Answer

In the United States, plasma glucose is standardly reported in milligrams per deciliter (mg/dL).

OGT - Oral Glucose Tolerance Practice Test