Growth Hormone Induces Low-Density Lipoprotein Clearance but not Bile Acid Synthesis in Humans

Abstract

Objective-Growth hormone (GH) induces hepatic low-density lipoprotein (LDL) receptors and lowers plasma cholesterol.We characterized the influence of GH treatment on plasma LDL clearance in normal humans and investigated the relative role of LDL receptor (LDLR) activity and stimulation of bile acid synthesis in subjects with different LDLR expression. Methods and Results-Plasma clearance of autologous 125 I-LDL was measured before and during 3 weeks of treatment with GH (0.1 IU/kg per day) in 9 healthy young males. Plasma LDL cholesterol was reduced by 13% and the fractional catabolic rate of LDL increased by 27%. More marked changes were seen in a patient with hypopituitarism substituted with GH (0.07 IU/kg per day) for 3 months. In a second study, GH dose-dependently reduced LDL cholesterol and increased Lp(a) levels in 3 groups of males: younger and elderly healthy subjects and heterozygous familial hypercholesterolemia (FH). No effect on bile acid synthesis measured by the plasma marker 7␣-hydroxy-4-cholesten-3-one was observed. In an LDLR-deficient FH homozygote, LDL cholesterol was not affected by GH. Conclusions-GH

Circulating Human Hepcidin-25 Concentrations Display a Diurnal Rhythm, Increase with Prolonged Fasting, and Are Reduced by Growth Hormone Administration

“…described (29 ). Because the mean baseline hepcidin-25 concentrations in the young participants [3.9 (0.8) g/L] and the older participants [5.9 (1.6) g/L] were similar, we analyzed the groups together.…”

“…During the other days, participants were sleep deprived. These individuals were treated daily with GH for 3 weeks, with the dosage increasing each week (0.1 IU ⅐ kg Ϫ1 ⅐ day Ϫ1 administered during the final week), as previously described (29 ). All participants gave informed consent, and all studies were approved by the Ethics Committee of Karolinska Institute.…”

Circulating Proprotein Convertase Subtilisin Kexin Type 9 Has a Diurnal Rhythm Synchronous With Cholesterol Synthesis and Is Reduced by Fasting in Humans

“…The effects of GH treatment ( Figure 5A-5C) were evaluated by analyses of samples from 15 healthy men treated with increasing doses of GH for 1 week per dose; the last week, 0.1 IU/kg per day was taken. 28 Atorvastatin, 80 mg/d, was given to 19 subjects (14 women and 5 men) for 4 weeks in a double-blind crossover design with a 4-week washout; fasting morning samples were drawn ( Figure 5D-5F).…”

“…28 Atorvastatin, 80 mg/d, was given to 19 subjects (14 women and 5 men) for 4 weeks in a double-blind crossover design with a 4-week washout; fasting morning samples were drawn ( Figure 5D-5F).…”

“…Fifteen healthy men received increasing doses of GH for 3 weeks, with a final dose of 0.1 IU/kg per day. 28 Individual levels before and after 3 weeks of GH therapy are given. P values were calculated using the paired Student t test.…”