c-peptide and Drug-Overdose

After beta-cell stimulation by carbohydrate or other secretagogues, insulin and C-peptide are secreted into the portal vein in a 1:1 molar ratio. A large fraction of endogenous insulin is cleared by the liver, whereas C-peptide, which is cleared primarily by the kidney and has a lower metabolic clearance rate than insulin, traverses the liver with essentially no extraction by hepatocytes. Hence, the molar ratio of insulin to C-peptide in peripheral venous blood (ICPR) should be less than 1.0 during fasting and feeding, unless exogenous insulin is introduced into the systemic circulation. Consequently, an ICPR in excess of 1.0 in a hypoglycemic patient argues persuasively for surreptitious or inadvertent insulin administration and against insulinoma (or sulfonylurea ingestion) as the cause of the hypoglycemia. This conclusion is supported by personal experience and by the literature.

Topics: Adult; Aged; C-Peptide; Diagnosis, Differential; Drug Overdose; Factitious Disorders; Female; Humans; Hypoglycemia; Infant; Insulin; Insulinoma; Male; Middle Aged; Osmolar Concentration; Pancreatic Neoplasms

Topics: Adult; Antidepressive Agents, Second-Generation; Blood Glucose; C-Peptide; Cyclohexanols; Drug Overdose; Female; Glucose; Humans; Hypoglycemia; Insulin; Venlafaxine Hydrochloride

In continuation to part I, a literature review is presented concerning biochemical problems of forensic post mortem cases of unclear hyperglycaemia or hypoglycaemia. Clinical parameters for this purpose were recently reviewed. Particular attention was paid to the detection of diabetic ketoacidosis, of hyperosmolar coma, insulinoma, insulin-induced or oral diabetic-induced hypoglycaemia. The second part of the review discusses the analytes ketone bodies, synthetic insulins, human insulin, C-peptide, proinsulin and insulin antibodies. Special interest is given to post mortem matrices for those analytes to reference concentrations, stability data, analytic interferences and analytical procedures which should be used in toxicological laboratories willing to detect diabetic metabolism disorders after death.

Topics: C-Peptide; Diabetic Ketoacidosis; Drug Overdose; Forensic Pathology; Glucose Metabolism Disorders; Humans; Insulin; Ketone Bodies; Postmortem Changes; Proinsulin

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

Topics: Aged; Aged, 80 and over; C-Peptide; Cross-Sectional Studies; Drug Overdose; Female; Glipizide; Glyburide; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Male; Middle Aged; Prospective Studies; Sulfonylurea Compounds

We report a case of an 82 year-old woman who had two episodes of documented hypoglycemia. Initial laboratory testing revealed hyperinsulinemia and a negative serum sulfonylurea screen. While these data suggested the presence of an insulinoma, further evaluation of the case revealed inadvertent ingestion of glimepiride, a sulfonylurea not included in the standard serum sulfonylurea screen.

Topics: Aged; Aged, 80 and over; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Drug Overdose; Female; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Sulfonylurea Compounds

Four cases of self-injected insulin overdose in nondiabetic individuals are presented. Included are two cases of presumed insulin overdose (no autopsy), one case with elevated vitreous insulin (autopsy), and one case with elevated postmortem blood insulin and low blood C peptide (autopsy). These cases demonstrate the need for a thorough scene investigation, complete autopsy, and proper collection and storage of specimens to certify a death caused by insulin intoxication as well as to determine the manner of death. Appropriate collection and preservation of postmortem blood samples are discussed.

Topics: Adult; Autopsy; C-Peptide; Drug Overdose; Female; Humans; Hypoglycemic Agents; Injections; Insulin; Male; Middle Aged; New Mexico; Suicide