Abstract | CONTEXT: The very low GH concentration in obesity is commonly attributed to high body fat mass; however, the influence of overeating on GH secretion is not clear. OBJECTIVE: The aim of the study was to examine the effects of 2 wk of overeating on changes in GH secretion. SETTING: Subjects were admitted to the hospital and stayed within the Michigan Clinical Research Unit throughout the entire 2-wk overeating period. PARTICIPANTS: We studied seven healthy, nonobese men (body mass index, 24 ± 1 kg/m(2); age, 25 ± 1 yr). INTERVENTION: Subjects ate standardized meals containing 70 kcal/kg fat free mass/d (∼4000 kcal/d) for 2 wk. MAIN OUTCOME MEASURES: Twenty-four-hour plasma concentrations of GH (every 20 min) and insulin (every 2 h) were measured before overeating (baseline), on d 3, and after 2 wk of overeating. RESULTS: Compared with baseline, average 24-h plasma GH concentration declined nearly 80% by d 3 of overeating (1.30 ± 0.18 vs. 0.36 ± 0.09 ng/ml; P = 0.01). This marked suppression of GH secretion occurred in the absence of an increase in body weight (77.0 ± 2.2 vs. 76.4 ± 2.4 kg). At the same time, average 24-h insulin concentration doubled (16.6 ± 2.1 vs. 31.7 ± 5.8 μU/ml; P = 0.009). After 2 wk, body weight significantly increased (79.0 ± 2.1 kg; P < 0.001), and body fat increased by more than 10% (P = 0.002). However, this did not induce a further suppression in plasma GH concentration (0.33 ± 0.08 ng/ml). CONCLUSION:
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Authors | Andrea S Cornford, Ariel L Barkan, Jeffrey F Horowitz |
Journal | The Journal of clinical endocrinology and metabolism
(J Clin Endocrinol Metab)
Vol. 96
Issue 3
Pg. 824-30
(Mar 2011)
ISSN: 1945-7197 [Electronic] United States |
PMID | 21209037
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
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Chemical References |
- Blood Glucose
- Fatty Acids, Nonesterified
- Insulin
- Insulin-Like Growth Factor Binding Protein 3
- Triglycerides
- Human Growth Hormone
- Insulin-Like Growth Factor I
- Hydrocortisone
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Topics |
- Adiposity
(physiology)
- Adult
- Blood Glucose
(metabolism)
- Body Composition
(physiology)
- Body Mass Index
- Circadian Rhythm
- Fatty Acids, Nonesterified
(blood)
- Human Growth Hormone
(blood)
- Humans
- Hydrocortisone
(blood)
- Hyperinsulinism
(blood, etiology)
- Hyperphagia
(blood)
- Insulin
(blood)
- Insulin-Like Growth Factor Binding Protein 3
(blood)
- Insulin-Like Growth Factor I
(metabolism)
- Male
- Triglycerides
(blood)
- Young Adult
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