MedicalResearch.com Interview with>
Katarina Borer, Ph.D. Professor
School of Kinesiology
The University of Michigan
Ann Arbor, MI
MedicalResearch.com: What is the background for this study?
Response: This study was part of the doctoral dissertation of Po-Ju Lin, who is now a post-doctoral fellow at the University of Rochester. With this study, we wanted to answer three questions:
(1) Is daily carbohydrate load responsible for evening glucose intolerance and post-meal insulin resistance. (Evening glucose intolerance represents well-documented higher glucose and insulin responses in the evening than in the morning when the same quantity of glucose is eaten or infused intravenously) To answer this question we offered two daily meals containing about 800 Kcal and either 30% or 60% of carbohydrates.
(2) Will exercise before the meals improve glucose tolerance (glucose clearance from the blood and insulin response) after eating? (Exercise is a well-known means of increasing glucose uptake by the muscle and of increasing muscle sensitivity to insulin action for a number of hours after exercise). To answer this question we had the subjects exercise for two hours walking on a treadmill at 45% of their maximal aerobic effort one hour before each meal.
(3) Is the upper-intestinal hormone GIP involved in any effects associated with variation in dietary carbohydrate? (GIP or glucose-dependent insulinotropic peptide, stimulates insulin secretion in advance of absorbed glucose).