Glycated hemoglobin: a useful post-mortem reference marker in determining diabetes

Glycated hemoglobin (HbA(1c)) has been demonstrated to be a useful marker for long-term glucose control in diabetes. This parameter characterizes each non-enzymatic fixation of glucose on hemoglobin. It is a useful test in addition to periodic glycemia controls since it reflects the mean glycemia of the past 60 days. We studied the conservation of HbA(1c) at 4 degrees C as a function of time with different anti-coagulants and preservatives (3, 6 months, 1 year). A total of 106 tests were performed using the high performance liquid chromatography (HPLC) method dedicated to the semi-automatic analysis of HbA(1c) (Bio-Rad) and we applied the method in forensic cases. Conservation at 4 degrees C was good for as long as 3 months in blood samples collected with fluoride and 6 months in samples collected in a dry or in a heparinized tube. In non-diabetic subjects, HbA(1c) reference values obtained from forensic samples were identical to those of living controls (3.5-6.25% of total hemoglobin). All positive HbA(1c) results were confirmed by a medical evaluation. This method was successfully applied to five forensic cases. In cases of increased acetonemia, acetone or isopropanol are easily measured. However, in some unexplained post-mortem circumstances, increased HbA(1c) permits to differentiate alcoholic or starvation ketoacidosis from the diabetic cases. Glycated hemoglobin should, therefore, be considered the forensic marker of choice in the post-mortem diagnosis of a diabetic disorder and demonstrates its usefulness in post-mortem validation.