Glucose tolerance test performed in the afternoon.

The availability of afternoon glucose tolerance test for the diagnosis of diabetes mellitus was investigated. Fifty grams glucose tolerance test was performed twice in 52 patients of various diseases, i.e., one test was made in the morning and another was done in the afternoon after taking an ordinary break fast alone. No significant difference was seen between the two tests. Hence, we can use the glucose tolerance test for the diagnosis of mild diabetes in the afternoon instead of the test in the early morning without any change of criteria. There was also no significant difference in the plasma insulin response to glucose ingestion when it was given in the morning or in the afternoon.