Growth hormone assays: early to latest test generations compared.
We compared the data from four growth hormone (GH) immunoassays for analyzing 24-h GH profiles in four apparently normal subjects and four obese subjects (508 serum samples). The detection limit was 0.02 microgram/L for one immunochemiluminometric assay (ICMA), 0.1 microgram/L for two IRMAs, and 0.4 microgram/L for one RIA. All GH pulses with a peak ICMA value > 1 microgram/L were detected by each of the other methods. Overall, the correlation coefficient between the values obtained with all four assays exceeded 0.90. However, for GH concentrations < or = 0.25 microgram/L, acceptable concordance (r2 > or = 0.80) was reached only between the ICMA and one IRMA; between the ICMA and the RIA, concordance was acceptable only for GH concentrations > or = 10 micrograms/L. In the normal subjects, the percentage of undetectable values was 0% with the ICMA but 29% with one of the IRMAs; in obese subjects, the corresponding values were 12% and 38%.
Center for the Study of Biological Rhythms (CERB), School of Medicine, Université Libre de Bruxelles, Belgium. mbaleria@med.ulb.ac.be
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M
L'Hermite-Balériaux
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G
Copinschi
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E
Van Cauter
D000328:Adult; D000375:Aging; D005260:Female; D019382:Human Growth Hormone / Q000097:blood* / Q000378:metabolism; D006801:Humans; D007118:Immunoassay / Q000379:methods* / Q000706:statistics & numerical data; D015592:Immunoradiometric Assay / Q000706:statistics & numerical data; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood; D011863:Radioimmunoassay / Q000706:statistics & numerical data
D019382:Human Growth Hormone