title: Comparison of two methods for measurement of equine insulin.
abstract: Diagnosis of equine hyperinsulinemia requires an accurate method for quantification of equine insulin concentrations. The objectives of the current study were to compare 2 commercially available techniques for measurement of equine insulin, the radioimmunoassay (RIA) and chemiluminescent immunoassay (CIA). Recovery was poor for both assays, but worse for the CIA. Serial dilution of a high endogenous insulin sample yielded better linearity for the RIA ( r2= 0.99, P < 0.001) than the CIA ( r2= 0.92, P = 0.009). Bland-Altman analysis indicated that the CIA was, on average, 91 pmol/l higher than the RIA, with wide limits of agreement (95% limits of agreement: -508 to 691 pmol/l). These findings suggest that results between the assays should not be considered interchangeable.
authors.affiliation: Department of Physiological Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK (Banse, McCann, Yang, McFarlane).|Department of Veterinary Clinical and Diagnostic Sciences, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada (Wagg).
authors.forename: Heidi E
authors.initials: HE
authors.lastname: Banse
authors.affiliation: Department of Physiological Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK (Banse, McCann, Yang, McFarlane).|Department of Veterinary Clinical and Diagnostic Sciences, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada (Wagg).
authors.forename: Joseph
authors.initials: J
authors.lastname: McCann
authors.affiliation: Department of Physiological Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK (Banse, McCann, Yang, McFarlane).|Department of Veterinary Clinical and Diagnostic Sciences, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada (Wagg).
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.affiliation: Department of Physiological Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK (Banse, McCann, Yang, McFarlane).|Department of Veterinary Clinical and Diagnostic Sciences, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada (Wagg).
authors.forename: Catherine
authors.initials: C
authors.lastname: Wagg
authors.affiliation: Department of Physiological Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK (Banse, McCann, Yang, McFarlane).|Department of Veterinary Clinical and Diagnostic Sciences, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada (Wagg).
authors.forename: Dianne
authors.initials: D
authors.lastname: McFarlane
mesh_terms: D000818:Animals; D006736:Horses / Q000378:metabolism*; D007328:Insulin / Q000378:metabolism*; D008163:Luminescent Measurements / Q000379:methods / Q000662:veterinary*; D011863:Radioimmunoassay / Q000379:methods / Q000662:veterinary*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D007328:Insulin
keywords: Bias; chemiluminescent immunoassay; insulin; linearity; radioimmunoassay; recovery