Adiponectin Polymorphisms, Insulin Resistance, and Pharmacokinetics in Obesity
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.
|Study Design:||Endpoint Classification: Pharmacokinetics/Dynamics Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Diagnostic
|Official Title:||Adiponectin Polymorphisms, Insulin Resistance, and Pharmacokinetics in Obesity|
- plasma concentration of drugs fentanyl and propofol [ Time Frame: measured for 12 hours (beginning of anesthesia to 12 hours after) ] [ Designated as safety issue: Yes ]
Plasma concentration over time will be measured and modeled in order to calculate drug clearance, volume of distribution, area under the curve, and micro rate constants.
Knowledge of these variables will allow safer administration of anesthetic drug administration in the obese population.
- time to loss of conciousness [ Time Frame: measured once per study (at the time of induction of anesthesia) ] [ Designated as safety issue: Yes ]The time from propofol and fentanyl administration (time 0) until loss of consciousness will be measured in order to measure a component of drug response.
- partial pressure of carbon dioxide in blood [ Time Frame: measured once immediately before the operation and approximately every 30 minutes for 3 hours after the operation ] [ Designated as safety issue: Yes ]The investigators will measure arterial blood gases to obtain blood carbon dioxide partial pressures as a measure of respiratory depression caused by fentanyl.
- Adiponectin plasma protein levels [ Time Frame: measured once (immediately before the operation) ] [ Designated as safety issue: No ]The investigators will measure specific levels of the protein adiponectin in the blood, to determine if quantitative expression of adiponectin can predict insulin resistance in obesity and drug metabolism and response.
- Adiponectin gene polymorphisms [ Time Frame: measured once per study (immediately before the operation) ] [ Designated as safety issue: No ]The investigators will look at specific genetic variants of the adiponectin gene to determine if expression of specific variants can predict insulin resistance and changed in drug response and metabolism.
|Study Start Date:||November 2011|
|Estimated Study Completion Date:||September 2016|
|Estimated Primary Completion Date:||September 2016 (Final data collection date for primary outcome measure)|
Experimental: Propofol and Fentanyl administration
Propofol and Fentanyl will be administered to each subject. Each subject will have blood drawn to determine pharmacokinetic variables. Processed EEG will be used to determine pharmacodynamics. Plasma samples will be used to ascertain adiponectin levels and for DNA sampling for analysis of adiponectin single nucleotide polymorphisms.
Drug: Propofol, Fentanyl
Propofol will be administered to all patients via infusion at a dose of 2 mg/kg lean body weight/minute. The infusion will stop once loss of consciousness is reached. Fentanyl will be administered via target controlled infusion to achieve a plasma concentration of 2 ng/ml.
|Contact: Jerry Ingrande, M.D., M.S.||email@example.com|
|United States, California|
|Stanford University School of Medicine, Department of Anesthesia||Recruiting|
|Stanford, California, United States, 94305|
|Contact: Jerry Ingrande, M.D., M.S. 650-723-7377 firstname.lastname@example.org|