The primary objective of this study is to determine the influence of insulin resistance on drug metabolism and response in obese subjects. The investigators hypothesize that expression of adiponectin (a hormone secreted by fat tissue), and specific variants in the adiponectin gene can predict the insulin resistance and drug response among obese subjects.

The following study will hypothesizes that insulin resistance causes changes in drug metabolism, elimination, and effect. We will differentiate the insulin resistant phenotype amongst obese individuals on the basis of both laboratory (fasting insulin, triglycerides, fasting glucose) analysis, and quantitative and qualitative adiponectin expression. We will determine the effect of insulin resistance on the pharmacokinetics and pharmacodynamics of anesthetic induction agents and opioids, using propofol and fentanyl as examples.

Inclusion Criteria:

• Inclusion criteria include patients of adult age
• American Society of Anesthesiologists Class I, II, or III, and undergoing elective surgical procedures requiring general anesthesia
• Body mass index greater than 35

Exclusion Criteria:

• Patients with evidence of hepatic, renal, or cardiovascular dysfunction
• History of difficult tracheal intubation, or adverse reaction to anesthesia shall be excluded from the study
• Patients taking prescribed or over-the-counter anxiolytics, narcotics, or sleeping aids, will also be excluded

pharmacokinetic models will be published after data analysis and study completion