Experimental protocol: All subjects were admitted to the hospital at 0700 h after an overnight fast and had the radial artery (A) and a forearm deep vein (V) catheterized. A meal (730kcal, 50%carbohydrate, of which 38% was starch, 40% fat, and 10% protein) was given at least 1 h after catheter insertion and was consumed within 20 min. Blood samples were drawn from both sites before the meal (at -30 and 0 min) and at 30- to 60-min intervals for 300 min thereafter for measurements of thyroid hormones,glucose, total cholesterol, LDL Cholesterol, HDL Cholesterol, triglycerides, Apolipoprotein A1, Apolipoprotein BII and Lp(a).Forearm blood flow was measured with strain-gauge plethysmography. After the first meal tolerance test, treatment with 50μg of thyroxine or placebo, once daily, was initiated for a 2-month period. Then a second identical test was repeated. Special care was taken in order to avoid the induction of subclinical hyperthyroidism, that is suppression of TSH below 0.27 μU/ml, as it has recently been shown that the latter is also an insulin-resistant condition.