title: Serum insulin-like growth factor-1 measurements in dogs: performance characteristics of an automated assay and study of some sources of variation.
abstract: The aim of this study was to evaluate the performance characteristics of an automated immunoassay for canine insulin-like growth factor 1 (IGF-1) measurement and to investigate the possible effects of some sources of variation, such as diurnal variations, feeding/fasting cycles, and glucocorticoid administration, in dogs. The immunoassay evaluated had an adequate analytical performance with intra- and inter-assay coefficients of variation (CVs) lower than 10%, linear regression equations with correlation coefficients of 0.9993 and 0.9988 after serial dilutions, and a limit of quantification of 7.1 ng/mL that was even lower than that reported by the manufacturer. The assay was significantly affected by hemolysis and lipemia producing a significant decrease in IGF-1 concentrations, but not by bilirubinemia.Serum IGF-1 concentrations did not show significant diurnal changes in fed or fasted dogs and were not affected by glucocorticoid administration.
authors.affiliation: Department of Animal Medicine and Surgery, University of Murcia, Murcia, Spain.
authors.forename: Asta
authors.initials: A
authors.lastname: Tvarijonaviciute
authors.forename: Fernando
authors.initials: F
authors.lastname: Tecles
authors.forename: José M
authors.initials: JM
authors.lastname: Carrillo
authors.forename: José M
authors.initials: JM
authors.lastname: Carillo
authors.forename: Monica
authors.initials: M
authors.lastname: Rubio
authors.forename: José J
authors.initials: JJ
authors.lastname: Ceron
mesh_terms: D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology; D004285:Dogs / Q000097:blood*; D005260:Female; D007124:Immunoenzyme Techniques / Q000662:veterinary; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008163:Luminescent Measurements / Q000662:veterinary; D008297:Male; D008775:Methylprednisolone / Q000494:pharmacology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D007334:Insulin-Like Growth Factor I; D008775:Methylprednisolone