Essentially, there is very little difference between an OGTT and a GTT, as the terms are often used interchangeably. According to the reference, the oral glucose tolerance test (OGTT) is sometimes called a glucose tolerance test (GTT).
This means that in most cases, when someone refers to a GTT, they are likely referring to the OGTT.
However, it is worth noting the existence of related tests:
- Glucose Challenge Test: The reference also mentions that a shorter, 1-hour version of the test is called the glucose challenge test. This is different from a full OGTT/GTT and is typically used for gestational diabetes screening.
| Test Name | Abbreviation | Duration | Primary Use |
|---|---|---|---|
| Oral Glucose Tolerance Test | OGTT | Usually 2 hours | Diagnosing diabetes and insulin resistance |
| Glucose Tolerance Test | GTT | Usually 2 hours | Diagnosing diabetes and insulin resistance |
| Glucose Challenge Test | N/A | 1 hour | Gestational diabetes screening |
In summary, while GTT and OGTT are essentially the same thing, context is important. If clarification is needed, specifically asking for the "oral" glucose tolerance test can avoid any ambiguity.
