title: Diurnal variations in twenty-four-hour energy expenditure during growth hormone treatment of adults with pituitary deficiency.
abstract: The effects of growth hormone (GH) treatment on 24-h energy expenditure (EE) were studied in a open trial over a period of 4 weeks. Five subjects, four men and one woman, with a history of complete GH deficiency were included. All the subjects were examined on 2 consecutive days on baseline and, thereafter, at six occasions during a period of 1 month (days 1, 2, 5, 8, 15, and 30). The dose of GH was 0.25 U/kg.week, administered sc once a day in the evening. EE was determined in a chamber for indirect calorimetry. Body composition was determined with dual-energy x-ray absorptiometry and computed tomography using a four-scan technique. Blood samples were examined using well-established RIAs. During the first 2 weeks, 24-h EE increased by 6 +/- 3% (range 1-8%) from 40.9 +/- 4.8 to 42.9 +/- 4.8 kcal/24 h.kg (P < 0.05), sleeping metabolic rate by 14 +/- 3% (range 10-18%) from 28.4 +/- 1.9 to 32.9 +/- 2.2 kcal/24h.kg (P < 0.001), and basal metabolic rate by 11 +/- 7% (range 0-18%) from 29.6 +/- 2.4 to 33.3 +/- 2.6 kcal/24h.kg (P < 0.05). No change was found in daytime EE. The increase in EE covaried with changes in insulin-like growth factor 1, the free T3/free T4 ratio, insulin-like growth factor-binding protein-3, and the aminoterminal procollagen III peptide but not with changes in body composition. It is suggested that the stimulating effect of GH on EE occurs gradually during a 2-week period and is only detectable during night and morning hours, when significant levels of GH occur.
authors.affiliation: Department of Medicine, Sahlgrenska University Hospital, Göteborg, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Stenlöf
authors.forename: J O
authors.initials: JO
authors.lastname: Johansson
authors.forename: L
authors.initials: L
authors.lastname: Lönn
authors.forename: L
authors.initials: L
authors.lastname: Sjöström
authors.forename: B A
authors.initials: BA
authors.lastname: Bengtsson
mesh_terms: D000328:Adult; D015415:Biomarkers; D001823:Body Composition; D002940:Circadian Rhythm; D004734:Energy Metabolism; D005260:Female; D019382:Human Growth Hormone / Q000172:deficiency* / Q000627:therapeutic use*; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood; D010900:Pituitary Diseases / Q000188:drug therapy* / Q000473:pathology; D011347:Procollagen / Q000097:blood; D013963:Thyroid Hormones / Q000097:blood
chemical_list: D015415:Biomarkers; D018972:Insulin-Like Growth Factor Binding Protein 3; D010446:Peptide Fragments; D011347:Procollagen; D013963:Thyroid Hormones; C041876:procollagen Type III-N-terminal peptide; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I