Ghrelin and Insulin Resistance

Role of Ghrelin in the Improvement of Insulin Resistance After Roux-en-Y Gastric Bypass Surgery

Ghrelin, a hormone produced in the stomach that stimulates hunger and food intake, declines immediately after weight loss surgery. Some studies suggest that ghrelin may worsen an individual's ability to respond to insulin. The purpose of this study is to determine if the decline in ghrelin levels after weight loss surgery contributes to the improvement of insulin sensitivity.

Inclusion Criteria for RYGB group:

• Age 18-65
• BMI > 35 kg/m2
• Scheduled for bariatric surgery at Vanderbilt University Medical Center

Inclusion Criteria for Lean group:

• Age 18-65
• BMI < 30kg/m2

Exclusion Criteria:

• Prior bariatric surgery
• Serum creatinine > 1.5 mg/dl
• Hepatic enzyme elevations > 2x upper limits of normal
• Current use of warfarin or clopidogrel
• Intercurrent infections
• Females with positive pregnancy test
• Abnormal ECG