SERPINE1 and diabetes mellitus: In the present study, the multiplex biometric immunoassay technique was applied in order to determine the amounts of 10 diabetes-related protein biomarkers known to be involved in the regulation of glucose metabolism, namely: C-peptide, ghrelin, gastric inhibitory polypeptide (GIP), glucagon-like peptide-1 (GLP-1), glucagon, insulin, leptin, plasminogen activator inhibitor-1 (PAI-1), resistin and visfatin.