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).

Inclusion criteria: 

18 - 60 years of age
Aim 1: Healthy lean men and women, BMI<24 kg/m2, with normal fasting glucose (blood glucose
between 60 and 100mg/dl and normal glucose tolerance on OGTT (blood glucose <140 mg/dl at 2
hours post glucose challenge) at the screening visit.
Aim 2: Overweight and obese men and women, BMI 25 – 35 kg/m2

Exclusion criteria:
Type 1 and type 2 diabetes
Surgery in the past 90 days
Previous surgery of the spleen or splenectomy, esophagus, lungs, stomach, duodenum, or liver
Recent traumatic injury, including intracerebral hemorrhage and visceral injury
End stage renal disease and/or uremia
Active malignancy
Previous leukemia and/or lymphoma
Human immunodeficiency virus infection or AIDS
Rheumatoid arthritis or other immune-mediated diseases (e.g. inflammatory bowel disease)
Arrhythmias, including but not limited to, atrial fibrillation, atrial flutter, bradycardia, ventricular
arrhythmias, and A-V block
Implanted pacemaker or cardioverter/defibrillator (AICD)
History of stable or unstable angina, myocardial infarction, angioplasty or coronary arterial by-pass
grafting surgery
History of stroke or TIA
History of deep venous thrombosis (DVT) and/or pulmonary embolism (PE)
Previous episodes of pancreatitis
Spinal disorders
Chronic pain syndromes
History of thrombosis or bleeding disorders
Stage III-IV pressure ulcers
Sickle cell anemia or other anemia syndromes
Monocytosis
Thrombocytopenia
Diagnosed with fever of unknown origin (FUO) Previously or currently implanted vagus nerve stimulator
Previously or currently implanted spinal cord stimulator
Other chronically-implanted electronic medical device
History of seizures
History of cancer
Individuals who have taken any of the following medications within two weeks of receiving
ultrasound delivery: anti-coagulant, anti-platelet, anti-inflammatory, immunosuppressive agents,
alpha and/or beta adrenoceptor blocking agents, anti-seizure medications, anti-diabetic medication
Individuals with a substance abuse problem
Pregnant women
Ascites detected in the abdomen that may effect delivery of shear wave elastroghapy pulse