Growth hormone (GH) therapy in GH-deficient adults influences the responseto a dietary load of cholesterol and saturated fat in terms of cholesterolsynthesis, but not serum low density lipoprotein cholesterol levels

An increased dietary load of cholesterol (ch and saturated fat increases se rum low density lipoprotein ch (LDL-ch) levels. GH therapy in GH-deficient adults decreases serum LDL-ch levels. In the rat, GH is important for resis tance to dietary cholesterol in terms of serum cholesterol levels. The aim of this study was to investigate the influence of GH on the effects of an i ncrease in the intake of cholesterol and saturated fat on serum lipoprotein s and markers for cholesterol synthesis in man. Six GH-deficient adults wer e given an isocaloric diet enriched in cholesterol and saturated fat for 17 days with and without GH therapy (1-1.5 U/day). Serum cholesterol, LDL-ch, apolipoprotein B (apoB, and apoA1 levels increased during the diet period with GH therapy and tended to increase during the diet period without GH. H owever, GH therapy did not influence the dietary effect on serum cholestero l, LDL-ch, apoA1, or apoB levels. Serum levels of triglycerides, very low d ensity lipoprotein ch, high density lipoprotein ch, and apoE were not affec ted by diet or GH therapy. GH therapy increased serum lipoprotein(a) levels , but did not affect the response to diet. The serum total Delta(7)-lathost erol/cholesterol ratio increased less during the diet period with GH therap y than during the diet period without GH. Serum 7 alpha-hydroxy-4-cholesten -3-one levels tended to increase during both diet periods, but were not inf luenced by GH treatment. Serum plant sterol levels did not change. These re sults indicate that GH counteracts an increase in cholesterol synthesis ind uced by a high fat diet without affecting bile acid synthesis or sterol abs orption, GI-I therapy did not have any major influence on the dietary effec ts on serum lipoprotein levels.