Insulin overdose with fatal outcome?: Two forensic cases

Intentional overdose with insulin preparations is rare. However, fatal consequences due to severe hypoglycemia could occur. Postmortem toxicology screening of insulin is a challenge, given the chemical characteristics of this protein and the difficulty of distinguishing between endogenous and exogenous insulin in blood. Here, we describe two cases of patients with diabetes using insulin and oral anti-diabetics. The main question in both cases was whether or not disturbance in glucose metabolism contributed to death. In case A, there was strong evidence that self-poisoning with insulin and subsequent hypoglycemia caused the death. However, this could not be confirmed due to lack of adequate forensic toxicology tests. In case B, no hypoglycemia was observed. Though, compared with case A, additional forensic examination was performed to investigate whether glycemic disturbances could have contributed to the death. In this report, we focus on the most appropriate analytical methods for the detection of exogenous insulin in the human body and give recommendations for toxicology testing of glucose levels and insulin in postmortem specimens.