IGF-binding protein-1 levels are related to insulin-mediated glucose disposal and are a potential serum marker of insulin resistance.
OBJECTIVE
IGF-binding protein (IGFBP)-1 is negatively regulated by insulin. We determined whether the measurement of IGFBP-1 in serum is a useful marker of insulin resistance.


METHODS
Twenty-three subjects underwent a euglycemic insulin clamp. Glucose disposal rates (M) were then correlated with measurements of IGFBP-1, fasting insulin levels, homeostasis model assessment (HOMA), and BMI.


RESULTS
IGFBP-1 levels more strongly correlated with M (R = 0.73) than the other parameters such as BMI or HOMA. The level of this protein decreased in individuals who became more insulin sensitive by exercise training.


CONCLUSIONS
These studies show a strong correlation between insulin sensitivity and the serum levels of IGFBP-1. These studies suggest, therefore, that measurement of this protein may be valuable in identifying those individuals with insulin resistance and those individuals who respond to interventional strategies.
Maddux
Betty A
BA
Department of Medicine, Diabetes Center, University of California, San Francisco, 2200 Post, C415, 94143-1616, USA. bmaddux@itsa.ucsf.edu
Chan
Adelene
A
De Filippis
Elena A
EA
Mandarino
Lawrence J
LJ
Goldfine
Ira D
ID
D000328:Adult; D015415:Biomarkers / Q000097:blood*; D001786:Blood Glucose / Q000378:metabolism*; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000502:physiology*; D007333:Insulin Resistance / Q000502:physiology*; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood*; D008297:Male; D008875:Middle Aged
D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D018970:Insulin-Like Growth Factor Binding Protein 1