Reference intervals for Insulin-like Growth Factor-1 (IGF-1) from birth to senescence: Results from a multicenter study using a new automated chemiluminescence IGF-1 immunoassay conforming to recent international recommendations

Autor: Bidlingmaier, M., Friedrich, N., Emeny, R.T., Spranger, J., Wolthers, O.D., Roswall, J., Koerner, A., Obermayer-Pietsch, B., Hübener, C., Dahlgren, J., Frystyk, J., Pfeiffer, A.F., Döring, A., Bielohuby, M., Wallaschofski, H., Arafat, A.M.
Jazyk: angličtina
Rok vydání: 2014
Zdroj: J. Clin. Endocrinol. Metab. 9, 1712-1721 (2014)
Popis: Context: Measurement of IGF-1 is a cornerstone in diagnosis and monitoring of GH-related diseases, but considerable discrepancies exist between analytical methods. A recent consensus conference defined criteria for validation of IGF-1 assays and for establishment of normative data. Objectives: Our objectives were development and validation of a novel automated IGF-1 immunoassay (iSYS; Immunodiagnostic Systems) according to international guidelines and establishment of method-specific age- and sex-adjusted reference intervals and analysis of their robustness. Setting and Participants: We conducted a multicenter study with samples from 12 cohorts from the United States, Canada, and Europe including 15ü014 subjects (6697 males and 8317 females, 0-94 years of age). Main Outcome Measures: We measured concentrations of IGF-1 as determined by the IDS iSYS IGF-1 assay. Results: A new IGF-1 assay calibrated against the recommended standard (02/254) and insensitive to the 6 high-affinity IGF binding proteins was developed and rigorously validated. Age- and sex-adjusted reference intervals derived from a uniquely large cohort reflect the age-related pattern of IGF-1 secretion: a decline immediately after birth followed by an increase until a pubertal peak (at 15 years of age). Later in life, values decrease continuously. The impact of gender is small, although across the lifespan, women have lower mean IGF-1 concentrations. Geographical region, sampling setting (community or hospital based), and rigor of exclusion criteria in our large cohort did not affect the reference intervals. Conclusions: Using large cohorts of well-characterized subjects from different centers allowed construction of robust reference ranges for a new automated IGF-1 assay. The strict adherence to recent consensus criteria for IGF-1 assays might facilitate clinical application of the results.
Databáze: OpenAIRE