Ethylene glycol poisoning may be associated with elevated post-mortem vitreous glucose level

Ethylene glycol (EG) is a toxic chemical that is sometimes used as ethanol substitute. Besides the desired intoxicating effects, the intake of EG may often lead to death unless timely treatment measures are provided by medical professionals. We examined 17 fatal EG poisonings between 2016 and March 2022 in Finland in terms of forensic toxicology and biochemistry results and demographic information. Most of the deceased were male and the median (range) age was 47 (20-77) years. Of the cases, 6 were suicides, 5 accidents and in 7 cases the intent remained undetermined. In all cases, vitreous humour (VH) glucose was above the limit of quantitation 0.35 mmol/L (mean: 5.2 mmol/L; range 0.52-19.5 mmol/L). Other markers of the glycaemic balance were within the normal range in all except one case. As EG is not routinely screened for in most laboratories but only analysed in cases where the intake of EG is suspected, some fatal EG poisonings may remain unrecognised in post-mortem (PM) investigations. Although various conditions may induce hyperglycaemia, it is worthwhile keeping in mind that elevated PM VH glucose levels that cannot be otherwise explained may suggest intake of ethanol substitutes.

Characteristics of post-mortem beta-hydroxybutyrate-positivet cases - A retrospective study on age, sex and BMI in 1407 forensic autopsies

BACKGROUND

Post-mortem biochemistry, including the analysis of beta-hydroxybutyrate (BHB), is increasingly employed in forensic medicine, especially in conditions such as diabetes and chronic alcoholism. However, not much is known about the associations between age, body mass index (BMI), and sex and BHB concentrations in ketoacidotic conditions.

AIM

To retrospectively study the association between age, BMI and sex in several conditions, such as diabetic ketoacidosis (DKA), alcoholic ketoacidosis (AKA), and elevated post-mortem BHB concentrations.

METHODS

1407 forensic autopsy cases analysed for BHB were grouped by diagnosis: DKA, AKA, HHS [hyperosmolar hyperglycaemic state], acidosis NOS [not otherwise specified], or hypothermia. Age, sex, BMI and the concentrations of blood alcohol, vitreous glucose and blood BHB were recorded.

RESULTS

Cases of AKA and DKA were most numerous (184 and 156, respectively). In DKA and in its male subgroup, cases with severe ketosis (BHB>1000 µg/g) were younger and had a lower BMI than those with moderate ketosis (BHB 250-1000 µg/g) and controls (P<0.001). In DKA and in its female subgroup, cases with moderate ketosis cases were older (P = 0.0218 and P = 0.0083) than controls. In AKA and in its male subgroup, cases with severe ketosis had a lower BMI than those with moderate ketosis (P = 0.0391 and P = 0.0469) and controls (P<0.001). Cases with moderate ketosis had a lower BMI than controls (P<0.001).

CONCLUSIONS

BHB concentration is associated with BMI in DKA and AKA, and with both BMI and age in DKA. Constitutional factors should, therefore, be considered in potential AKA and DKA cases.

Lactate determination in human vitreous humour by capillary electrophoresis and time of death investigation

Forensic inquests, particularly, in assessing time since death currently recognize the importance of the analysis of vitreous humour (VH) biomarkers. Present research, studies, and validates the determination of lactate (La) in VH by CZE with indirect UV detection. The BGE (pH 8.9) consisted of Tris buffer (37 mM) containing 4-methoxybenzoic acid (4 mM) and alkyl-trimethyl-ammonium bromide (1.2 mM). Each VH specimen was diluted with a butyric acid solution (internal standard 0.057 mM) and La and butyrate were separated within 3-5 min (30 kV). The La LOQ and LOD were 4 and 2 mM, respectively. The calibration curve linearity ranged from 4 to 80 mM; intra- and interruns precisions were less than 10% for standard as well as for VH specimen, respectively. To investigate postmortem interval (PMI) and VH lactate level correlation, human VH specimens were collected during autopsy (n = 40) and stored at -20°C until assay. La levels ranged from 16 to 42 mM; PMI values ranged from 10 to 141 h. La (mM) and PMI (h) correlation was statistically significant (r² = 0.527; p < 0.05). In conclusion, the present CZE analysis is efficacious to determine VH La as a biomarker for PMI investigation.

Vitreous humor endogenous compounds analysis for post-mortem forensic investigation

The chemical and biochemical analysis of bodily fluids after death is an important thanatochemical approach to assess the cause and time since death. Vitreous humor (VH) has been used as a biofluid for forensic purposes since the 1960s. Due to its established relevance in toxicology, a literature review highlighting the use of VH with an emphasis on endogenous compounds has not yet been undertaken. VH is a chemically complex aqueous solution of carbohydrates, proteins, electrolytes and other small molecules present in living organisms; this biofluid is useful tool for its isolated environment, preserved from bacterial contamination, decomposition, autolysis, and metabolic reactions. The post-mortem analysis of VH provides an important tool for the estimation of the post-mortem interval (PMI), which can be helpful in determining the cause of death. Consequently, the present review evaluates the recent chemical and biochemical advances with particular importance on the endogenous compounds present at the time of death and their modification over time, which are valuable for the PMI prediction and to identify the cause of death.

Glycated haemoglobin (HbA1c) for postmortem diagnosis of diabetes

The study was conducted at the Estonian Forensic Science Institute in 2008–2014 as continuous part of our previous study of alcohol and premature death in Estonian men. Autopsy data from 504 cases of male deaths (ages 19–79) were collected and blood and urine samples for glycated haemoglobin (HbA_1c), liver enzymes and alcohol concentration were analysed. The aim of our research was to find undiagnosed diabetes and diabetes risk cases postmortem on the basis of increased values of HbA_1c. HbA_1c was within the reference value 4.8%–5.9% (29–42 mmol/mol), in 88.1% (n = 444) of cases, below reference value in 2.4% (n = 12), in the risk group of diabetes, HbA_1c 6.0%–6.4% (42–46 mmol/mol) was within 5.8% (n = 29), and HbA_1c result of ≥6.5% (48 mmol/mol) manifested in 3.8% (n = 19) of cases. The higher the age, the more cases with HbA_1c value ≥6.0% (42 mmol/mol) occurred. In the group of external causes of death (n = 348), the HbA_1c value of ≥6.5% (48 mmol/mol) HbA_1c occurred in four cases. The HbA_1c value was ≥6.5% (48 mmol/mol) in 78.9% of 156 cases when the cause of death was disease, of which 58% were cardiovascular diseases. The prevalence of diabetes and diabetes risk was found lower compared to population-based study, as majority of the deceased were young and middle-aged males and no females were included. In the case of poisoning with narcotic substances, HbA_1c was within the reference range. A negative correlation occurred between alcohol intoxication and HbA_1c value. A positive correlation between ALT and HbA_1c was found – the higher stage of liver damage correlated with the higher HbA_1c level.

Challenges in investigation of diabetes-related aviation fatalities-an analysis of 1491 subsequent aviation fatalities in USA during 2011-2016

Diabetes mellitus (DM) could cause pilot incapacitation and result in aviation fatalities. The mechanisms could be directly as a consequence of acute hypoglycemia/subacute diabetic ketoacidosis (DKA) or indirectly as an acute cardiovascular event by contributing to the development of atherosclerosis in coronary or carotid and cerebral arteries. In this study, DM-related fatal flight accidents in the US National Transport Bureau's database between years 2011-2016 were analyzed with special emphasis on postmortem (PM) glucose levels and correlation of toxicological reports with anamnestic information on DM. Additionally, autopsy results on coronary arteries were reviewed. In 43 out of 1491 (~ 3%) fatal accidents pilots had DM. Postmortem glucose or glycated hemoglobin percentage (Hb1Ac) was measured in 12 of the 43 cases; while antidiabetic medication was found in 14 of the cases (only two of the cases had both glucose measurements and medication). With the increasing prevalence of DM, a possibility of pilot incapacitation due to DM or complications of DM should be actively studied, even if no anamnestic information of DM was available. While PM hypoglycemia is difficult to assess, we propose a systematic investigation based on measurement of glucose, Hb1Ac%, and ketone bodies, and documentation of atherosclerotic lesions in major arteries to identify or rule out DM as a cause of pilot incapacitation.

Risk Factors for Fatal Hyperglycaemia Confirmed by Forensic Postmortem Examination - A Nationwide Cohort in Sweden

AIMS/HYPOTHESIS

The aim of this study was to identify risk factors associated with confirmed fatal hyperglycaemia, which could predispose potentially preventable deaths in individuals on glucose lowering drugs.

METHODS

A retrospective register-based case-control study conducted on a nationwide cohort with individuals who died due to hyperglycaemia as determined by forensic postmortem examination, in Sweden August 2006 to December 2012. Vitreous glucose was used to diagnose hyperglycaemia postmortem. The forensic findings stored in the National Forensic Medicine Database were linked to nationwide registers. Cases that died due to confirmed hyperglycemia with dispensed glucose lowering drugs were identified and living controls with dispensed glucose lowering drugs were randomly selected in the Swedish prescribed drug register and matched on age and sex. Information on comorbidities, dispensed pharmaceuticals, clinical data and socioeconomic factors were obtained for cases and controls. Adjusted multiple logistic regression models were used to identify risk factors associated with fatal hyperglycaemia.

RESULTS

During the study period 322 individuals, mostly males (79%) with the mean age of 53.9 years (SD.± 14) died due to confirmed hyperglycaemia. Risk factors for fatal hyperglycaemia included; insulin treatment (OR = 4.40; 95%CI,1.96, 9.85), poor glycaemic control (OR = 2.00 95%CI,1.23, 3.27), inadequate refill-adherence before death (OR = 3.87; 95%CI,1.99, 7.53), microvascular disease (OR = 3.26; 95% CI, 1.84, 5.79), psychiatric illness (OR = 2.30; 95% CI,1.32, 4.01), substance abuse (OR = 8.85; 95%CI,2.34, 35.0) and/or living alone (OR = 2.25; 95%CI,1.21, 4.18).

CONCLUSIONS/INTERPRETATION

Our results demonstrate the importance of clinical attention to poor glycaemic control in subjects with psychosocial problems since it may indicate serious non-adherence, which consequently could lead to fatal hyperglycaemia.

The usefulness of point-of-care (POC) tests in screening elevated glucose and ketone body levels postmortem

The aim was to evaluate the performance of point-of-care (POC) tests in detecting glucose and ketone bodies in postmortem (PM) samples and to assess the usefulness of POC tests in sample screening for more precise analyses. Glucose and ketone body, β-hydroxybutyrate (BHB), were measured from vitreous humor (VH) in 52 autopsy cases with a POC blood glucose monitoring device (BGMD). In addition glucose and ketone bodies, acetone (Ac) and acetoacetate (AcAc), were measured from urine samples in another set of 59 cases with semi-quantitative stick tests. The results were compared to the concentration in VH measured with validated methods (values ≥ 7mmol/l indicate possible hyperglycemia and total ketone body levels ≥ 3mmol/l ketoacidosis). The sensitivity for glucose with the BGMD was 1.0 and specificity 0.94 when the threshold value for the meter to predict elevated glucose was set to ≥ 10mmol/l. The correlation between the BGMD and the validated method was strong (R(2)=0.89). For detecting ketoacidosis, the BGMD had a sensitivity of 1.0 and specificity of 0.73, when the threshold value was set to 2.5mmol/l. The urine stick test presented a sensitivity of 0.89 and specificity of 0.90 for detecting elevated VH glucose concentration. The sensitivity and specificity for the stick test to detect cases with possible ketoacidosis were 0.84 and 0.68, respectively. According to the results, BGMD can be reliably applied for sample screening, although more samples need to be analyzed for delineating the correct threshold values. In the case of glucose, the urine stick tests could be indicative in detecting cases with VH glucose ≥ 10mmol/l. For predicting possible ketoacidosis with elevated VH total ketone bodies, the stick test is not reliable as the test presented both false-positive and -negative results.

Postmortem diagnosis of diabetes mellitus and its complications

Diabetes mellitus has become a major cause of death worldwide and diabetic ketoacidosis is the most common cause of death in children and adolescents with type 1 diabetes. Acute complications of diabetes mellitus as causes of death may be difficult to diagnose due to missing characteristic macroscopic and microscopic findings. Biochemical analyses, including vitreous glucose, blood (or alternative specimen) beta-hydroxybutyrate, and blood glycated hemoglobin determination, may complement postmortem investigations and provide useful information for determining the cause of death even in corpses with advanced decompositional changes. In this article, we performed a review of the literature pertaining to the diagnostic performance of classical and novel biochemical parameters that may be used in the forensic casework to identify disorders in glucose metabolism. We also present a review focusing on the usefulness of traditional and alternative specimens that can be sampled and subsequently analyzed to diagnose acute complications of diabetes mellitus as causes of death.