The impact of obesity, fat distribution, and energy restriction on insulin-like growth factor-1 (IGF-1), IGF-binding protein-3, insulin, and growth hormone.
The aim of this study was to characterize the association between serum insulin-like growth factor-1 (IGF-1) and obesity, as well as fat distribution, before and during moderate energy restriction (1,200 kcal/d). In 51 females and nine males having a body mass index (BMI) between 27 and 39 kg/m2, relationships between serum IGF-1, IGF-binding protein-3 (IGFBP-3), insulin, growth hormone (GH), blood glucose, and anthropometric measurements of body fat were examined. The patients were studied before treatment and again after 8 and 16 weeks of dieting. Visceral adipose tissue (AT) was estimated by anthropometric computed tomography (CT)-calibrated equations. In females, IGF-1 was inversely associated with the abdominal sagittal diameter (SagD) and with the visceral AT (r = -.41, P = .006). No significant correlations were found between IGF-1 and BMI or other indices of adiposity. Weight loss caused a temporary increase in IGF-1 concentrations (P = .03) and continued decrements in blood glucose levels (P = .0004 at 16 weeks). A statistically significant inverse correlation between IGF-1 and blood glucose levels was present before (r = -.30, P = .02) and after 8 (r = -.37, P = .007) and 16 (r = .02, P = .02) weeks of dietary treatment. Both serum IGF-1 and insulin levels were positively correlated with serum IGFBP-3 levels (r = .34, P = .009 and r = .34, P = .008, respectively). We conclude that IGF-1 levels in obese females reflect the intraabdominal fat mass rather than obesity per se. IGF-1 and blood glucose levels are inversely correlated in obesity before and during energy restriction.
Rasmussen
M H
MH
Department of Endocrinology, Hvidovre Hospital, University of Copenhagen, Denmark.
Frystyk
J
J
Andersen
T
T
Breum
L
L
Christiansen
J S
JS
Hilsted
J
J
D000273:Adipose Tissue / Q000473:pathology / Q000502:physiology*; D000328:Adult; D000375:Aging / Q000097:blood / Q000502:physiology; D000886:Anthropometry; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D002352:Carrier Proteins / Q000097:blood*; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D013006:Growth Hormone / Q000097:blood*; D006801:Humans; D007328:Insulin / Q000097:blood*; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000178:diet therapy / Q000503:physiopathology*; D011863:Radioimmunoassay
D001786:Blood Glucose; D002352:Carrier Proteins; D007328:Insulin; D018969:Insulin-Like Growth Factor Binding Proteins; D008055:Lipids; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone