To determine the effect of corticosteroids on lipoprotein metabolism in healthy subjects, we measured lipoprotein lipid and apoprotein levels in eight normolipidemic healthy men before, during, and after administration of oral prednisone 0.35 mg/kg/d. After 14 days of prednisone, there was a significant increase in levels (mg/dL) of very low density lipoprotein-triglyceride (VLDL-TG) (51 +/- 9 v 92 +/- 11, P less than .01), very low density lipoprotein-cholesterol (VLDL-C) (19 +/- 2 v 28 +/- 3, P less than .01), high density lipoprotein-cholesterol (HDL-C) (39 +/- 1 v 50 +/- 4, P less than .05), apolipoprotein (apo) AI (124 +/- 7 v 147 +/- 8, P less than .01), and apo E (3.1 +/- 0.4 v 4.1 +/- 0.4, P less than .01). In addition, the activity of lipoprotein lipase but not hepatic lipase in postheparin plasma also was higher after prednisone treatment. All values returned to baseline within 2 weeks after discontinuation of prednisone. Short-term administration of corticosteroids has a consistent effect on the metabolism of both VLDL and HDL.