The Effect of Surgically Induced Weight Loss on Endocrine Function, Cardiovascular Function and Body Composition

The Effect of Surgically Induced Weight Loss on Endocrine Function, Cardiovascular Function and Body Composition

This study is being conducted to evaluate changes in sugar, metabolism, heart function and changes in body composition as patients lose weight following bariatric surgery. The investigators will compare improvements of the above changes as a function of the four different types of bariatric surgery. The investigators believe the most beneficial and safest procedure will be the Roux-en-Y.

The study will also examine the response of the pancreas (the insulin-producing organ) to a sugar load, as well as to a hormone called Glucagon Like Peptide 1 (GLP-1), which is released from your gut to maximally stimulate your pancreas. The release of this hormone increases when you eat food and it causes the pancreas to release more insulin than does sugar alone. Volunteers will have 22 visits over a two year period. Only people having Roux-en-Y gastric bypass surgery, gastric sleeve surgery, duodenal switch gastric surgery or lap-band/gastric banding surgery may join. Seventy volunteers will be recruited to take part in this study.

Inclusion Criteria:

• Male and female volunteers 21-65 years.
• BMI > 40.
• Preoperative hematocrit level of at least 34% for women and 38% for men.
• Postoperative hematocrit level of at least 34% for women and 36% for men.

Exclusion Criteria:

• Volunteers whose hematocrit level does not meet the above criteria.
• Pregnant and or lactating females.