The ghrelin response to exercise before and after growth hormone administration

TY - JOUR

T1 - The ghrelin response to exercise before and after growth hormone administration

AU - Vestergaard, E T

AU - Dall, R

AU - Lange, K H W

AU - Kjaer, M

AU - Christiansen, J S

AU - Jorgensen, J O L

PY - 2007/1

Y1 - 2007/1

N2 - CONTEXT: We have previously shown that exercise-induced GH release is not mediated by ghrelin, but it remains to be studied whether the increase in GH may suppress postexercise ghrelin levels.OBJECTIVE: The objective of this study was to characterize systemic ghrelin levels after exercise with and without concomitant GH administration.DESIGN, PARTICIPANTS, AND INTERVENTION: Group A: Twenty-nine elite athletes (age, 18-37 yr) were studied after a maximal exercise test. Group B: In a double blind, placebo-controlled, parallel study, 32 healthy subjects (age, 18-33 yr) were randomized to placebo, GH 0.1 IU/kg per day, or GH 0.2 IU/kg per day for 4 wk. These subjects performed a multistage fitness test to assess maximum oxygen uptake at baseline and after 4 wk. We measured total circulating ghrelin levels before and immediately after exercise and at 15, 30, 60, 90, and 120 min after exercise.RESULTS: Group A: Serum ghrelin levels after exercise decreased significantly (P < 0.01). Group B: Exercise at baseline was associated with a significant lowering of ghrelin levels after exercise (P < 0.0001). In addition, 4 wk of high-dose GH were followed by a further approximately 20% reduction in basal and after exercise serum ghrelin (micrograms per liter): 0.78 (range 0.52-1.17) vs. 0.63 (range 0.50-0.91), P < 0.05.CONCLUSIONS: 1) Ghrelin levels decrease significantly after exercise in elite athletes and healthy subjects. 2) High-dose GH suppresses ghrelin levels. 3) These data support the hypothesis that GH feedback inhibits ghrelin secretion.

AB - CONTEXT: We have previously shown that exercise-induced GH release is not mediated by ghrelin, but it remains to be studied whether the increase in GH may suppress postexercise ghrelin levels.OBJECTIVE: The objective of this study was to characterize systemic ghrelin levels after exercise with and without concomitant GH administration.DESIGN, PARTICIPANTS, AND INTERVENTION: Group A: Twenty-nine elite athletes (age, 18-37 yr) were studied after a maximal exercise test. Group B: In a double blind, placebo-controlled, parallel study, 32 healthy subjects (age, 18-33 yr) were randomized to placebo, GH 0.1 IU/kg per day, or GH 0.2 IU/kg per day for 4 wk. These subjects performed a multistage fitness test to assess maximum oxygen uptake at baseline and after 4 wk. We measured total circulating ghrelin levels before and immediately after exercise and at 15, 30, 60, 90, and 120 min after exercise.RESULTS: Group A: Serum ghrelin levels after exercise decreased significantly (P < 0.01). Group B: Exercise at baseline was associated with a significant lowering of ghrelin levels after exercise (P < 0.0001). In addition, 4 wk of high-dose GH were followed by a further approximately 20% reduction in basal and after exercise serum ghrelin (micrograms per liter): 0.78 (range 0.52-1.17) vs. 0.63 (range 0.50-0.91), P < 0.05.CONCLUSIONS: 1) Ghrelin levels decrease significantly after exercise in elite athletes and healthy subjects. 2) High-dose GH suppresses ghrelin levels. 3) These data support the hypothesis that GH feedback inhibits ghrelin secretion.

KW - Adolescent

KW - Adult

KW - Double-Blind Method

KW - Exercise

KW - Female

KW - Ghrelin

KW - Growth Hormone/pharmacology

KW - Human Growth Hormone/blood

KW - Humans

KW - Insulin-Like Growth Factor I/analysis

KW - Male

KW - Peptide Hormones/blood

U2 - 10.1210/jc.2006-1435

DO - 10.1210/jc.2006-1435

M3 - Journal article

C2 - 17032714

SN - 0021-972X

VL - 92

SP - 297

EP - 303

JO - Journal of Clinical Endocrinology and Metabolism

JF - Journal of Clinical Endocrinology and Metabolism

IS - 1

ER -