Evaluation of an Enzyme Immunometric Assay to Measure Serum Adiponectin Concentrations

Abstract

Adiponectin (also named apM1, Arcp-30, AdipoQ, or GBP-28), an abundant protein produced by adipose tissue, is regarded as one of the adipokines, which include leptin, resistin, interleukin-6, tumor necrosis factor-α, and plasminogen activator inhibitor-1, and other constituents necessary for endocrinologically active adipose tissue (1)(2)(3)(4). Decreased adiponectin concentrations have been associated with the fundamental components of the metabolic syndrome (3)(4), i.e., insulin resistance and type 2 diabetes (2)(5)(6)(7)(8)(9)(10), hypertension, endothelial dysfunction (11)(12), and increased susceptibility to atherosclerosis (13)(14). Despite its intriguing associations with the metabolic syndrome, the clinical use of adiponectin as an analyte remains to be defined. In addition to early in-house methods, most recent studies have been performed with ELISA-based methods or a RIA-based commercial method by Linco Research (8). However, reports comparing the separate methods have not been published, and the introduction of a commercially available ELISA-based method could enable even wider implementation of adiponectin measurements in the implicated fields of research. This study was undertaken to evaluate the analytical properties of an adiponectin assay based on a standard ELISA platform and to compare the results with the commercially available RIA-based assay. A total of 59 individuals from the personnel of the Turku University Central Hospital Laboratories (TUCH Laboratories) and their family members volunteered for this study. A brief questionnaire providing information about age (mean, 42.9 years; range, 18–65 years), sex (18 males and 41 females), height and weight (mean body mass index, 25.2 kg/m2; range, 18.8–36.3 kg/m2), chronic illnesses, regular medications, family history of diabetes and/or known cardiovascular disease, smoking, and menstrual status of the female participants was obtained. Only three of the participants had type 2 diabetes, and none …