Hyperinsulinemic-Euglycemic Clamp

The hyperinsulinemic-euglycemic clamp was performed as previously described (8,13). Briefly, the hyperinsulinemic-euglycemic clamp was initiated with the 90-min basal period (t = –90 to 0 min) followed by a 115-min clamp period (t = 0 to 115 min). The clamp period was initiated at t = 0 min by primed and continuous infusion of human insulin (2.5–1.25 mU ⋅ kg^–1 ⋅ min^–1, Humulin R; Eli Lilly). A priming dose of [3-³H]glucose (5 μCi) (Perkin Elmer) was administered at t = –90 min and was followed by infusion of the tracer at a rate of 0.05 μCi/min for 1.5 h. Glucose (30%) was infused at a variable rate to maintain blood glucose levels at 110–130 mg/dL. Tissue 2-[¹⁴C]-deoxy-d-glucose uptake was also measured as previously described (8,13).