Quantitative insulin and C-peptide levels among ED patients with sulfonylurea-induced hypoglycemia-a prospective case series.

Objective: The objective of this study was to measure the serum insulin and C-peptide concentrations among diabetic patients known to be taking sulfonylurea agents who presented to the emergency department with hypoglycemia thought to be due to therapeutic usage as opposed to overdose. A recently published systematic review of 22 articles involving 76 patients with sulfonylurea-induced hypoglycemia (glucose <49 mg/dL) resulting from accidental ingestion or intentional overdose found that patients had an average serum insulin concentration of 3.9 μIU/mL or higher and an average serum C-peptide concentration of 1.4 ng/mL or higher.

Methods: This is a prospective cross-sectional descriptive case series.

Results: Thirteen of 14 study subjects had initial insulin and C-peptide levels consistent with the diagnosis of sulfonylurea-induced hypoglycemia as previously defined among patients presenting after overdose.

Conclusion: Patients presenting with hypoglycemia resulting from therapeutic sulfonylurea use demonstrate similar insulin and C-peptide levels as has previously been published among patients who presented with presumed overdose.