Disorders of glucose metabolism: post mortem analyses in forensic cases–part II

Abstract

In continuation to part I, a literature review is presented concerning biochemical problems of forensic post mortem cases of unclear hyperglycaemia or hypoglycaemia. Clinical parameters for this purpose were recently reviewed. Particular attention was paid to the detection of diabetic ketoacidosis, of hyperosmolar coma, insulinoma, insulin-induced or oral diabetic-induced hypoglycaemia. The second part of the review discusses the analytes ketone bodies, synthetic insulins, human insulin, C-peptide, proinsulin and insulin antibodies. Special interest is given to post mortem matrices for those analytes to reference concentrations, stability data, analytic interferences and analytical procedures which should be used in toxicological laboratories willing to detect diabetic metabolism disorders after death.

Postmortem chemistry update part I

“…KernbachWighton and Püschel [82] proposed the lower limit of 100 μUI/ml for lethal insulin dosage. Musshoff et al [13] reported that clearly elevated serum insulin levels could be caused by intentional insulin overdose, because levels of 1,000 μUI/ml are rarely seen in patients with insulinsecreting tumours. Karlovsek [37,38] proposed a summary of the biochemical indicators which would support the hypothesis of hypoglycaemia at the time of death, including low or indeterminate glucose concentration in vitreous immediately after death; extremely low glycated haemoglobin in treated diabetics as a consequence of repeated hypoglycaemic states and biochemical and toxicological findings indicating insulin or anti-diabetic overdose.…”

“…This results in further mobilisation of liver glycogen and the release of glucose into blood circulation as a counterbalancing phenomenon. Considering the difficulty in interpreting postmortem blood glucose levels, other biological fluids, such as vitreous humor and cerebrospinal fluid, have been proposed in order to estimate the antemortem blood glucose concentrations [1,[12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29].…”

“…C peptide is more stable than insulin in postmortem blood. However, collection and storage of specimens for C peptide analyses require special handling: collection in heparinised tubes, separation of postmortem serum and, without delay, storage of the sample in a freezer [13,[69][70][71][72].…”

“…The number of substances that may be used for diagnostic purposes in forensic routine has increased significantly, though some studies have put back into question the usefulness of other molecules that are no longer systematically used. Postmortem determinations of a wide variety of substances are now technically possible in many biological fluids, including blood, vitreous humor, urine, cerebrospinal, pericardial and synovial fluids [2][3][4][5][6][7][8][9][10][11][12][13][14][15].…”

Iatrogenic injury and unexpected hospital death in the newborn

“…23,24 However, insulin levels can be measured in postmortem serum or urine if there is suspected insulin overdose. 25 Toxicological testing of premortem or postmortem serum can detect some drugs, including theophylline, narcotics, and digoxin. If a medication dilution or mixing error is suspected, or a wrong-drug administration is possible, save all syringes, intravenous fluid bags, and bottles in the patient's room for possible testing.…”