Fatal Insulin Overdoses: Case Report and Update on Testing Methodology

Area of Science:

• Forensic Pathology
• Toxicology
• Endocrinology

Background:

• Suicidal insulin overdose is an under-recognized cause of death.
• Diagnosis often relies on nonspecific autopsy findings and scene investigation.
• Patients with type 1 diabetes are at risk for exogenous insulin administration.

Observation:

• A fatal exogenous insulin overdose case in a type 1 diabetes patient is presented.
• Autopsy findings were non-contributory.
• Serum analog aspart insulin levels were significantly elevated (4000 uU/mL), approximately 10 times the upper therapeutic limit.

Findings:

• A novel immunocapture liquid chromatography-tandem mass spectrometry assay accurately quantified elevated aspart insulin levels.
• This assay could discriminate between various synthetic insulin analogs.
• Standard immunoassays showed variable sensitivity, with one platform detecting elevated levels while another did not.

Implications:

• Highlights the importance of specific assays for detecting synthetic insulin analogs in forensic toxicology.
• Provides guidance on sample collection and analytical options for insulin testing in overdose cases.
• Emphasizes the need for awareness of insulin overdose as a cause of death and relevant autopsy findings.