title: Hyposomatotropism blunts lipolysis in abdominally obese women.
abstract: Abdominal obesity is associated with reduced 24-h plasma GH concentrations. It is unclear whether hyposomatotropism in abdominally obese humans is compensated by up-regulation of GH receptor sensitivity or causes less biological effect in target tissues. We, therefore, determined the responsiveness of adipose tissue to the lipolytic action of GH in abdominally obese (OB) and normal weight (NW) postmenopausal women. An iv bolus of recombinant human GH or placebo was randomly administered to eight NW [body mass index (BMI): 22.2 +/- 1.6 kg/m(2)] and eight abdominally OB (BMI: 32.1 +/- 2.6 kg/m(2)) women. Lipolysis was measured by infusion of D5-glycerol and modeled as a function of plasma GH concentrations to describe adipose tissue responsiveness. Similar plasma GH concentration peaks ( approximately 20 mU/liter) were achieved by GH injection in both groups. During placebo conditions, the average plasma GH level was significantly lower in OB compared with NW women (0.74 +/- 0.52 vs. 2.08 +/- 1.18 mU/liter, P = 0.023). Adipose tissue responsiveness, expressed as glycerol rate of appearance per kilogram of fat mass per unit plasma GH concentration was not different in both groups (NW: 1.06, OB: 0.68, P > 0.05). These results suggest that hyposomatotropism in abdominally obese individuals is not compensated by increased adipose tissue responsiveness to GH bio-action and, therefore, blunts lipolysis in these individuals.
authors.affiliation: Department of General Internal Medicine, Leiden University Medical Centre, Leiden 2300 RC, The Netherlands. m.m.buijs@lumc.nl
authors.forename: Madelon M
authors.initials: MM
authors.lastname: Buijs
authors.forename: Jacobus
authors.initials: J
authors.lastname: Burggraaf
authors.forename: Janneke G
authors.initials: JG
authors.lastname: Langendonk
authors.forename: Rik C
authors.initials: RC
authors.lastname: Schoemaker
authors.forename: Marijke
authors.initials: M
authors.lastname: Frölich
authors.forename: Jan-Willem
authors.initials: JW
authors.lastname: Arndt
authors.forename: Adam F
authors.initials: AF
authors.lastname: Cohen
authors.forename: Johannes A
authors.initials: JA
authors.lastname: Romijn
authors.forename: Mariette T
authors.initials: MT
authors.lastname: Ackermans
authors.forename: Hans P
authors.initials: HP
authors.lastname: Sauerwein
authors.forename: A Edo
authors.initials: AE
authors.lastname: Meinders
authors.forename: Hanno
authors.initials: H
authors.lastname: Pijl
mesh_terms: D000005:Abdomen; D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism; D015992:Body Mass Index; D005260:Female; D005990:Glycerol / Q000097:blood; D019382:Human Growth Hormone / Q000008:administration & dosage* / Q000097:blood; D006801:Humans; D007018:Hypopituitarism / Q000097:blood / Q000378:metabolism*; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008066:Lipolysis / Q000187:drug effects*; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000378:metabolism*
chemical_list: D018972:Insulin-Like Growth Factor Binding Protein 3; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; D005990:Glycerol