Correlation of serum IGF-I and IGFBP-1 and -3 to cardiovascular risk indicators and early carotid atherosclerosis in healthy middle-aged men.
OBJECTIVE
IGF-I, IGFBP-1 and IGFBP-3 are putative mediators in cardiovascular disease. The present study examined (i) the correlations of circulating IGF-I, IGFBP-1 and IGFBP-3 to established cardiovascular risk factors and signs of early atherosclerosis as reflected by ultrasound measurement of common carotid intima-media thickness (IMT), and (ii) whether serum concentrations of these analytes are modulated during alimentary lipaemia.


METHODS
Cross-sectional clinical study.


METHODS
A biobank and clinical database based on 96 healthy Caucasian men, aged 50 years, with an apolipoprotein (apo) E3/E3 genotype, who had originally undergone investigations of postprandial lipoprotein metabolism was used for the study.


METHODS
Total IGF-I, IGFBP-1 and IGFBP-3 were determined in serum by radioimmunoassay (RIA). Free IGF-I was measured by a commercial two-site immunoradiometric assay (IRMA).


RESULTS
In multivariate analyses, fasting serum free IGF-I correlated inversely with IMT and accounted for 5% of the variation in multiple R(2). When fasting serum IGFBP-1 was entered in the models instead of IGF-I, IGFBP-1 correlated positively with IMT and accounted for 6% of the variation in IMT. IGFBP-3 and total IGF-I were unrelated to IMT. There were no associations between free IGF-I and cardiovascular risk factors, whereas IGFBP-1 behaved like a component of the insulin resistance syndrome. Serum free IGF-I increased and IGFBP-1 decreased postprandially.


CONCLUSIONS
The data indicate that serum free IGF-I and IGFBP-1 are implicated in early atherosclerosis.
Boquist
S
S
Atherosclerosis Research Unit, King Gustaf V Research Institute, Department of Medicine, Karolinska Institute, Karolinska University Hospital, Stockholm, Sweden. susanna.boquist@karolinska.se
Ruotolo
G
G
Skoglund-Andersson
C
C
Tang
R
R
Björkegren
J
J
Bond
M G
MG
de Faire
U
U
Brismar
K
K
Hamsten
A
A
D002318:Cardiovascular Diseases / Q000097:blood*; D002340:Carotid Artery Diseases / Q000097:blood*; D059168:Carotid Intima-Media Thickness; D005215:Fasting / Q000097:blood; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood*; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period; D012307:Risk Factors