Age- and gender-specific reference ranges for serum insulin-like growth factor I (IGF-I) and IGF-binding protein-3 concentrations on the Immulite 2500: results of the Study of Health in Pomerania (SHIP).
BACKGROUND
The objective of the present study was to calculate age- and gender-specific reference ranges for serum insulin-like growth factor I (IGF-I) and insulin-like growth factor binding protein 3 (IGFBP-3) concentrations using quantile regression.


METHODS
From the Study of Health in Pomerania (SHIP), 1798 men and women aged 25-85 years were recruited. Serum IGF-I and IGFBP-3 concentrations were determined using a chemiluminescent immunometric assay on an Immulite 2500 analyzer. Quantile regressions were performed to calculate the 2.5th and 97.5th percentiles.


RESULTS
The reference ranges identified 43 (4.6%) women and 41 (4.8%) men with serum IGF-I concentrations, and 47 (5.0%) women and 42 (5.0%) men with serum IGFBP-3 concentrations outside the reference range.


CONCLUSIONS
The use of quantile regression results in accurate calculation of age- and gender-specific reference ranges for serum IGF-I and IGFBP-3.
Friedrich
Nele
N
Institute of Clinical Chemistry and Laboratory Medicine, Ernst Moritz Arndt University Greifswald, Greifswald, Germany. nele.friedrich@uni-greifswald.de
Krebs
Alexander
A
Nauck
Matthias
M
Wallaschofski
Henri
H
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008163:Luminescent Measurements / Q000295:instrumentation / Q000379:methods; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012737:Sex Factors
D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I