Omentectomy for the Treatment of Diabetes Mellitus Type 2
Condition: Diabetes Mellitus Type 2; Dyslipidemia; Hypercholesterolemia; Obesity
MeSH terms: Diabetes Mellitus; Hypercholesterolemia; Dyslipidemias; Diabetes Mellitus, Type 2
Study type: Interventional
Phase: Phase 1

Summary: 
      The purpose of this study is to determine whether laparoscopic removal of the omentum (thin
      layer of fat inside the abdomen) will significantly improve insulin resistance in patients
      with non-insulin dependent type 2 diabetes mellitus.
    

Detailed description: 
      Clinical studies have shown that central obesity is one of the strongest associations with
      Type II diabetes. Measurement of waist circumference at Vanderbilt was one of the most
      effective clinical measures of presence of type II diabetes and response to gastric bypass in
      a recent study. This central obesity points to the omentum as one of the major culprits for
      development and perpetuation of type II diabetes in humans. [1]

      Animal studies at Vanderbilt have shown in normal size dogs that surgical removal of the
      visceral fat (Omentectomy):

        -  Decreases basal hepatic glucose production by nearly 40%

        -  Results in decreased FFA delivery to the liver

        -  Increases glucose utilization by peripheral insulin dependent tissues, predominantly
           skeletal muscle. [2] The animal studies were started to pursue the positive results seen
           by Swedish investigators who randomized 50 patients to either gastric banding or to
           gastric banding with omentectomy. At 2 years both groups had statistically similar
           weight loss but the patients in the omentectomy group had 2 to 3 times the improvements
           in oral glucose tolerance, insulin sensitivity and fasting plasma glucose as compared to
           control subjects. [3] They concluded that omentectomy, when combined with gastric
           banding in morbidly obese patients had a significant positive effects on the glucose and
           insulin metabolism.

      Why does the removal of visceral fat (a very small percentage of the animal's weight) cause a
      40% increase in peripheral glucose metabolism? The omentum is known to be a repository for
      macrophages and the increase in macrophage numbers is proportional to the increase in
      adiposity in humans. Both macrophages and adipocytes produce adipokines and cytokines that
      are known to influence glucose and insulin metabolism. The omentum is also known to be the
      major contributor of Free Fatty Acids into the portal circulation which adversely affects the
      hepatic insulin resistance.

      Resection of the visceral fat which holds more numbers of the macrophages which in turn
      release the cytokines that preferentially disturb glucose metabolism should in theory then
      result in a marked improvement in glucose and fat metabolism.

      Hypothesis Removal of visceral fat (omentectomy) will significantly improve type II Diabetes
      and dyslipidemia.

      Specific Aim 1: Determine the improvement in glucose metabolism in patients with type II
      diabetes using Minimal model study at baseline and at 3 months post surgery Specific Aim 2:
      Determine the improvement in control of type II diabetes by measuring HgbA1c levels and the
      amount of oral medications taken to control their diabetes 3, 6 and 12 months post surgery.

      Specific aim 3: Determine the improvement in lipids by measuring fasting serum total
      cholesterol, HDL, LDL and Triglycerides at 0, 3, 6, and 12 months post surgery.

      Specific Aim 4: Determine the effect of omentectomy on markers of inflammation (C- reactive
      protein, interleukin 6) at 3, 6, and 12 months post op. These labs will be drawn but not
      assayed until we see the effects on insulin resistance.
    

Intervention name(s): removal of omentum
Intervention type(s): Procedure
Intervention description(s): patients with type 2 diabetes had their omentum removed
Other intervention name(s): laparoscopic omentum removal
Allocation: Non-Randomized
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Obesity; Omentectomy; Diabetes Mellitus Type 2; Laparoscopic; Dyslipidemia