Abstract
We herein describe the cases of two young Japanese adults who presented with excessive
daytime sleepiness (EDS). Based on their history, the postprandial nature of the sleepiness
was suspected, although the patients themselves were not aware of the association.
Oral glucose tolerance tests (OGTTs) reproduced the sleepiness and showed the patterns
of insulin resistance (IR) compatible with type-2 diabetes mellitus (T2DM) in one
patient and glucose intolerance in the other. There was no evidence of chronic hyperglycemia
in either patient. Antidiabetic medications resulted in the disappearance of EDS in
both patients; in one, a repeat OGTT revealed improved IR. We suggest that postprandial
somnolence can present with EDS, and it can be effectively treated with antidiabetic
medications, and that the OGTT can be useful in identifying IR, which may be the underliyng
cause of the excessive postprandial somnolence.
Keywords
postprandial period - disorder of excessive somnolence - oral glucose tolerance test
- insulin resistance
