Effect of Increased Free Fatty Acids on Leptin Function

We propose to test our hypotheses by conducting a non-blinded, interventional study
evaluating the effects of acute leptin administration on intracellular leptin signaling
pathways after a 6 hour infusion period comparing an oral high fat meal, high fat lipid
infusion, low fat lipid infusion, or placebo infusion (saline)iv lipid infusion, placebo
(saline) and oral high fat meal. After a screening visit, study participation involves 1 meal
pick-up visit, 1 overnight visit, and one 1 follow-up visit. Subjects will be randomized to
one of 4 groups: an oral high fat meal, fat emulsion 20% infusion , fat emulsion 10%
infusion, and a placebo (saline) infusion infusion and an oral high fat meal.

We plan to screen 100 male and postmenopausal female subjects, with BMI greater than 18
kg/m2, to consent 60 in order to have 32-48 evaluable subjects, 8-12 subjects per group,
completing all parts of the study.

The primary study outcome to be evaluated will be the changes in serum concentrations of
glucose, hormones influencing metabolism such as insulin, fat-cell-secreted proteins such as
leptin, molecules involved in metabolism such as free fatty acids (FFAs), and markers of
inflammation such as interleukin (IL)-2 and interferon (IFN)-gamma.

The secondary outcome will be to examine the impacts of increased FFAs on intracellular
leptin signaling by phosphorylation of STAT3.

Inclusion Criteria:

- Age 18-65

Exclusion Criteria:

1. Subjects with a history of any illness, other than obesity, that may affect insulin
sensitivity (anemia, infectious diseases, renal or hepatic failure, uncontrolled
hypertension, cancer, lymphoma, chronic inflammatory conditions such as inflammatory
bowel disease and rheumatoid arthritis, states of cortisol or growth hormone excess,
alcoholism or drug abuse, and eating disorders).

2. History of diabetes mellitus.

3. Subjects taking any medications that are known to influence glucose metabolism such as
glucocorticoids will also be excluded. We will screen for these conditions by means of
a detailed history and review of systems and physical examination (see below).

4. Subjects taking any medications known to affect lipids such as statins will also be
excluded. We will screen for these similar to above.

5. Cholesterol greater or equal to 250 mg/dL and/or triglyceride levels greater than 500
mg/dL at the time of screening, as determined by laboratory testing.

6. Subjects who have a known history of anaphylaxis or anaphylactoid-like reactions or
who have a known hypersensitivity to anesthetic agents such as Lidocaine or Marcaine
will be excluded from the study.

7. Hypersensitivity to fat emulsion or any component of the formulation; severe egg or
legume (soybean) allergies; pathologic hyperlipidemia, lipoid nephrosis, acute
pancreatitis associated with hyperlipemia.

8. Hypersensitivity to heparin or any component of the formulation

9. Severe thrombocytopenia, uncontrolled active bleeding, disseminated intravascular
coagulation (DIC); suspected intracranial hemorrhage.

10. Subjects with a history of bleeding dyscrasia, poor wound healing or any medical
condition precluding supine position will be excluded from the study.

11. Unable to follow study protocol or any condition that in the opinion of the
investigator makes the subject unsuitable for the study.

12. Pregnancy

13. Prior history of gastrectomy, gastric bypass surgery, or other weight loss surgery.