Influence of Central Nervous Insulin Action on Insulin Sensitivity of Peripheral Organs in Lean Versus Overweight Humans
Status:
Completed
Trial end date:
2015-12-01
Target enrollment:
Participant gender:
Summary
Research in animals and first experiments in humans indicate that insulin action in the brain
regulates peripheral insulin sensitivity. One major organ might be the liver. Previous
studies in humans showed that the human brain is an insulin sensitive organ in lean but not
in overweight/obese persons. Therefore, this study will include lean versus overweight/obese
persons.
In this study, insulin action will be introduced by intranasal insulin administration in lean
and overweight humans. As a control, placebo spray will be administered. To mimick the known
spill over of small amounts of intranasal insulin into circulation, a small bolus of insulin
will be administered over 15 minutes following placebo spray application.
Peripheral insulin sensitivity will be assessed by hyperinsulinemic-euglycemic glucose clamp
and glucose uptake and endogenous glucose production will be assessed by tracer dilution
technique. Autonomous nervous system activity will be addressed by heart rate variability.
Involved brain areas will be addressed by fMRI before and after nasal insulin application.