Effects of Hepatic Ultrasound on Metabolic Homeostasis

The general hypothesis is that ultrasound elastography directed towards hepatic portal sensory nerves can modulate glucose metabolism in humans. Aim #1: Determine whether ultrasound exposure at the porta hepatis will affect plasma glucose levels in lean, healthy control subjects. Aim #2: Determine whether three episodes of porta hepatic ultrasound exposure will affect plasma glucose levels as well as insulin sensitivity amongst overweight/obese individuals who have normal glucose tolerance or impaired glucose tolerance (as defined by OGTT).