Contributions of betahydroxybutyrate (BHB) determination and thanatological biochemistry in postmortem diagnosis of ketoacidosis-related fatalities: two case reports

Postmortem biochemical analyses are increasingly recognized as valuable tools to complement traditional forensic investigations, particularly in cases where the cause of death remains unclear after autopsy and toxicological analyses. Among these, the quantification of β-hydroxybutyrate (BHB) in femoral blood (FB) and/or vitreous humor (VH) has proven crucial in identifying fatal ketoacidosis. The authors report two forensic cases in which targeted biochemical markers (including BHB, vitreous glucose, creatinine, and blood HbA1c) were evaluated to support the diagnosis of metabolic fatal metabolic disturbances. The first case involved a 57-year-old man with a known history of mellitus diabetes and chronic alcohol abuse, found deceased at home with postmortem genital mutilations. The second case concerned a 75-year-old diabetic man discovered in a neglected state after several weeks of insulin withdrawal. In both cases, toxicological findings were non-conclusive. However, markedly elevated BHB concentrations were observed in FB and VH, strongly supporting a diagnosis of ketoacidosis. In Case 1, the combination of chronic alcohol abuse together with elevated BHB concentrations in FB and VH suggested alcoholic ketoacidosis (AKA), with possible contribution from underlying diabetic condition. In Case 2, the history of prolonged insulin deprivation, abnormally high vitreous glucose concentration, and markedly increased BHB concentrations in FB and VH were consistent with diabetic ketoacidosis (DKA). Elevated vitreous creatinine and reduced estimated glomerular filtration rate (eGFR) further supported pre-existing renal dysfunction in both cases. These findings highlight the importance of integrating biochemical markers into routine postmortem protocols, as they may provide critical insights into otherwise unexplained deaths.