Insulin-like growth factor-binding protein-1 is correlated with low density lipoprotein cholesterol in normal subjects.
Insulin-like growth factor-I (IGF-I) has been inversely associated with low-density lipoprotein (LDL) cholesterol in normal women with slightly elevated cholesterol levels and hypothyroid women. More than 95% of IGF-I circulates bound to binding proteins (IGFBPs); of these IGFBP-1 is of particular interest as it is inversely regulated by insulin and is thought to inhibit the action of IGF-I and IGF-II. We examined the relationship between IGFBP-1 and LDL cholesterol in 41 healthy adult subjects. LDL cholesterol correlated with the body mass index (r = 0.40, P < 0.01), sex (r = 0.51, P < 0.001) and IGFBP-1 levels (r = 0.36, P < 0.02). LDL cholesterol did not correlate with age (r = 0.25, P = not significant) or IGF-I (r = 0.06, P = not significant). Upon multivariate regression analysis, sex, body mass index and IGFBP-1 were all independent predictors of LDL cholesterol (all P < 0.05). Elevated IGFBP-1 levels have been associated with an inhibition of serum IGF-I bioactivity in children with insulin-dependent diabetes. IGFBP-1 also appears to inhibit IGF-I hexose-stimulated uptake. IGFBP-1 may also be inhibiting the effect of IGFs on the cellular metabolism of LDL cholesterol.
Hopkins
K D
KD
Department of Endocrinology and Chemical Pathology, United Medical and Dental Schools, St Thomas' Hospital, London, UK.
Lehmann
E D
ED
Parker
J R
JR
Gosling
R G
RG
D000328:Adult; D015992:Body Mass Index; D002352:Carrier Proteins / Q000378:metabolism*; D008078:Cholesterol, LDL / Q000097:blood*; D005260:Female; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007335:Insulin-Like Growth Factor II / Q000378:metabolism; D008297:Male; D012044:Regression Analysis; D012737:Sex Factors; D013002:Somatomedins / Q000378:metabolism*
D002352:Carrier Proteins; D008078:Cholesterol, LDL; D018970:Insulin-Like Growth Factor Binding Protein 1; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II