Diabetes mellitus (DM) is a group of metabolic disorders, that have become a
major cause of death worldwide. This study aimed to determine the usefulness
of diabetes-related laboratory tests for diagnosis of postmortem DM. From
March to August 2018, among the autopsy cases investigated by the National
Forensic Service, heart blood and vitreous humor samples from 253 cases
that had not been decomposed were collected, and the data from 208 cases
except 45 cases that were incapable of testing were analyzed for statistical
significance and compared with the causes of death on autopsy reports. The
levels of C-peptide, insulin, acetoacetate, β-hydroxybutyrate (β-HA), total
ketone, and HbA1c were measured in the heart blood, and the levels of glucose,
blood urea nitrogen, creatinine, and potassium were measured in the vitreous
humor. The levels of glucose in the vitreous humor and HbA1c, β-HA, and total
ketone in the heart blood were significantly correlated. C-peptide and insulin
levels were lower than normal levels in most cases (C-peptide 92.3%, P=0.480,
insulin 97.6%, P=0.589), and were not useful measures indicating diabetic
complications. In the group with DM history, the average levels of HbA1c from
the heart blood and glucose from the vitreous humor were higher than in those
with no or unknown history of DM, indicating their usefulness as diagnostic
tools. The results of this study suggest a postmortem DM diagnosis model.
Therefore, postmortem DM-related tests can help diagnose the cause of death
in forensic medicine.