Postmortem Analysis of Vitreous Humor For Detection of Antemortem Disorders in Glucose Metabolism. An Old Method Revisited

It has been estimated that 15% up to one third of cases of deaths due to diabetic ketoacidosis occur in individuals with so far unknown diabetes. Moreover, cardiac arrhythmias that occur during nocturnal hypoglycaemia include bradycardia and ectopics that may provoke lethal arrhythmias. As postmortem capillary glucose concentrations have no diagnostic value, the postmortem forensic proof of hyperglycaemia or hypoglycaemia remains a challenge. The established but rarely applied method of postmortem determination of glucose and lactate in vitreous humor with or without calculation of the sum formula of Traub could provide reliable exclusion or proof of severe antemortem disorders in glucose metabolism. To date, diagnostic puncture of vitreous humor is more established for the postmortem detection of diabetic ketoacidosis than for the exclusion or proof of lethal hypoglycaemia. Vitreous humor is protected from postmortem degradation and contamination due to its isolated localization. The autolytic process in vitreous humor is considerably delayed compared to blood or liquor. In vitreous humor also the triggering agent of hypoglycaemia (insulin, insulin analogues) is easier to be detected than in blood since insulins are very unstable in postmortem blood. Furthermore, parameters of long term glycaemic control such as 1,5-anhydroglucitol, HbA1c and fructosamine can be determined in vitreous humor. However, limitations and interference factors of this method should be carefully considered. So far, clinical diabetology has taken no broad notice of this useful forensic procedure.