Using stable isotope techniques to establish turnover rates for very low density lipoprotein (VLDL), a group of eight adult patients with growth hormone deficiency (GHD) exhibited an increased VLDL apoprotein B (apo B) secretion and decreased VLDL apoB metabolic clearance rate compared to controls. Such increased secretion is seen in some dyslipidemic states, including GHD, which are associated with atherosclerosis. The study of VLDL metabolism may provide a clue to the lipid metabolism disorder associated with GHD.