Significance of the Flat Oral Glucose Tolerance Test

A flat blood sugar response to the oral glucose tolerance test has long been accepted as an implication of impaired intestinal absorption of carbohydrate. However, this study indicates that the flat response is a normal variant and depends on how the test is performed and when the blood is sampled. It also is conjectured that the carbohydrate challenge may trigger a burst of insulin that modifies the blood sugar response.