%0 Journal Article %T Classification of Patients With GH Disorders May Vary According to the IGF-I Assay %+ AP-HP Hôpital Bicêtre (Le Kremlin-Bicêtre) %+ Signalisation Hormonale, Physiopathologie Endocrinienne et Métabolique %+ Service de génétique moléculaire, pharmacogénétique et hormonologie %+ Centre d'Investigation Clinique [Rennes] (CIC) %+ CHU Pontchaillou [Rennes] %+ CHU Necker - Enfants Malades [AP-HP] %+ Unité de Recherche Clinique des hôpitaux Pitié-Salpêtrière – Charles Foix [CHU Pitié Salpêtrière] (URC PSL-CFX) %+ Service d'endocrinologie %+ Service d’explorations fonctionnelles [CHU Necker] %A Mavromati, Maria %A Kuhn, Emmanuelle %A Agostini, Hélène %A Brailly-Tabard, Sylvie %A Massart, Catherine %A Piketty, Marie-Liesse %A Arnoux, Armelle %A Young, Jacques %A Souberbielle, Jean-Claude %A Chanson, Philippe %Z This work was supported by Programme Hospitalier de Recherche Clinique, French Ministry of Health Grant P081216/IDRCB 2009-A00892-55. M.M. received a grant from Fond National Suisse (Grant P1GEP3_155694) for her contribution to this work. %< avec comité de lecture %@ 0021-972X %J Journal of Clinical Endocrinology and Metabolism %I Endocrine Society %V 102 %N 8 %P 2844-2852 %8 2017-08-01 %D 2017 %R 10.1210/jc.2017-00202 %M 28505364 %K IGF-I %K Z-score %K SD score %K normative data %K reference range %K normal healthy population %K acromegaly %K growth hormone deficiency %Z Life Sciences [q-bio]Journal articles %X Context: Insulinlike growth factor I (IGF-I) measurement is essential for the diagnosis and management of growth hormone (GH) disorders. However, patient classification may vary substantially according to the assay technique. Objective: We compared individual patient data and classifications obtained with six different IGF-I assay kits in a group of patients with various GH disorders. Design: In this cross-sectional study, we measured IGF-I with six immunoassays in 102 patients with active or treated acromegaly or GH deficiency. IGF-I normative data previously established for the same six assay kits were used to classify the patients (high, low, or normal IGF-I levels), using both raw data and standard deviation scores (SDSs). Pairwise concordance between assays was assessed with Bland-Altman plots and with the percentage of observed agreement and the weighted κ coefficient for categorized IGF-I SDS. Results: We observed marked variability both across each individual's IGF-I raw data and across IGF-I SDS values obtained with each of the six immunoassays. Pairwise concordance between assay values, as assessed with the weighted κ coefficient, ranged from 0.50 (moderate) to 0.81 (excellent). Conclusion: Even when using normative data obtained in the same large population of healthy subjects and when using calculated IGF-I SDSs, agreement among IGF-I assay methods is only moderate to good. Differences in assay performance must be taken into account when evaluating and monitoring patients with GH disorders. This argues for the use of the same IGF-I assay for a given patient throughout follow-up. %G English %2 https://univ-rennes.hal.science/hal-01579404/document %2 https://univ-rennes.hal.science/hal-01579404/file/Classification%20of%20patients%20with%20GH%20disorders_accepted.pdf %L hal-01579404 %U https://univ-rennes.hal.science/hal-01579404 %~ INSERM %~ UNIV-RENNES1 %~ UNIV-PSUD %~ APHP %~ HL %~ CIC %~ CIC203 %~ STATS-UR1 %~ UR1-UFR-SVE %~ UR1-HAL %~ UR1-SDV %~ INSERM-SACLAY %~ UNIV-PARIS-SACLAY %~ UNIV-PSUD-SACLAY %~ TEST-UNIV-RENNES %~ TEST-UR-CSS %~ UNIV-RENNES %~ CHU-UNIV-PARIS5 %~ SORBONNE-UNIVERSITE %~ SU-INF-2018 %~ SU-MEDECINE %~ SU-MED %~ SU-TI %~ UR1-BIO-SA %~ PHYSENDO %~ ALLIANCE-SU %~ TEST3-HALCNRS