Detection of synthetic insulin in doping and forensic analyses

Background Insulin is essential for the regulation of glucose metabolism and exhibits anabolic/anticatabolic characteristics. Oversupply and undersupply pose acute health risks for the human organism. Objective Recombinantly produced insulins are classified as doping agents in sports and prohibited for individuals who do not suffer from insulin-dependent diabetes mellitus. In addition, the administration of insulins has been suspected and proven in a series of (attempted) suicides and homicides. The required analytical approaches necessitate particular sensitivity and specificity, applied to a variety of different available biological matrices. Methods By means of scientific articles published over the past 10 years on the development of analytical approaches for insulins in doping control samples and in forensic contexts as well as case reports, the progress in insulin detection concerning instrumentation, sample type and preparation is presented. Results and conclusion Similar approaches concerning the analysis of insulins have been established in doping controls and forensics; however, the available test matrices can be significantly different. While sports drug testing almost exclusively relies on blood and urine samples, matrices collected postmortem are considerably more variable and can include, e.g. vitreous humor and skin tissue. Depending on different case-related factors, such as prevailing medical conditions or postmortem intervals, specific matrices and sample collection strategies are advantageous. Especially the immediate preservation of dried blood spots as well as the collection of (suspected) injection sites appear warranted in order to facilitate subsequent insulin analyses