This study is designed to test the hypothesis that a low-dose of fatty acid infusion (Intralipid/heparin) will cause mild insulin resistance. This dose-finding study is critical for future studies on free-fatty acid induced insulin resistance.~Healthy male and healthy female volunteers will undergo a 6 hour hyperinsulinemic-euglycemic clamp, in order to establish insulin sensitivity parameters in the presence of fatty acid co-infusion. The subjects will then return 1-3 weeks later, and undergo another 6 hour HIE clamp, this time in the presence of low-dose fatty acid co-infusion (30ml/hr). If this dose does not achieve ~25% reduction in the rate of glucose disposal, then the dose-confirmation study will be repeated 1-3 weeks later with a medium-dose fatty acid co-infusion (60ml/hr).~A dose-response effect of fatty acids on insulin resistance has been demonstrated before, but not in the precise conditions of our study. This dose-finding study is critical because future studies require a reliable dose of fatty acid infusion, and the exact dose of fatty acid infusion that causes mild insulin resistance may be different in the conditions of our study.
The primary goal of this study is to determine the dose of fatty acids that acutely induces mild insulin resistance in healthy volunteers. We hypothesize that a low-dose of fatty acid infusion (Intralipid/heparin) will cause a mild insulin resistance. The dose of fatty acid infusion that reliably causes mild insulin resistance will be selected for use in future studies.