c-peptide and Factitious-Disorders

Topics: Biomarkers; C-Peptide; Chromatography, Gel; Diabetes Mellitus, Type 2; Diagnostic Techniques, Endocrine; Factitious Disorders; Humans; Hypoglycemia; Immunoassay; Insulin Resistance; Insulin-Secreting Cells; Insulinoma; Kidney Diseases; Pancreatic Function Tests; Pancreatic Neoplasms; Proinsulin; Reference Values; Specimen Handling

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

Factitious hypoglycemia (FH) in a diabetic patient represents a difficult diagnostic and costly management problem. An adolescent diabetic with FH is reported. A literature search revealed 10 adolescent and 45 adult diabetic patients with FH. Tests currently available for diagnosis are evaluated. The role of psychiatric therapy in relation to overall management and prognosis is stressed.

Topics: Adolescent; Blood Glucose; C-Peptide; Child; Diabetes Mellitus, Type 1; Factitious Disorders; Humans; Hypoglycemia; Insulin; Male

Artifactual hypoglycemia results from either improper collection of blood samples or interfering substances in the blood. Such artifacts should be easily detected and avoided. Factitious hypoglycemia, on the other hand, results from deliberate subterfuge by the patient and may thus elude proper diagnosis for some time. The most common cause of factitious hypoglycemia is surreptitious injection of insulin, and this is best diagnosed by the triad of hypoglycemia, inappropriately high insulin levels, and low C-peptide levels. Persons with diabetes may also intentionally misuse blood glucose strips to create the impression of hypoglycemia.

Topics: Adolescent; Adult; Blood Glucose; Blood Preservation; Blood Specimen Collection; C-Peptide; Diabetes Mellitus; Factitious Disorders; False Positive Reactions; Female; Glycolysis; Humans; Hypoglycemia; Insulin; Middle Aged; Sulfonylurea Compounds

Factitious hypoglycemia is a factitious disorder according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), referring to intentionally covertly induced hypoglycemia, with potentially severe consequences. Knowledge of factitious hypoglycemia relies on case reports, and evidence-based information and guidelines are lacking. Diagnosing factitious hypoglycemia in insulin-treated diabetic persons is therefore challenging and often requires a long and costly process. Moreover, the typical metrics proposed to differentiate insulin-induced factitious hypoglycemia from insulinoma (i.e., high insulin and low C-peptide versus high insulin and high C-peptide, respectively) are not always applicable, depending on whether the insulin quantification method can detect the insulin analog. When factitious hypoglycemia is suspected, an emerging trend from recent publications advocates a combination of two insulin quantification methods with different cross-reactivity for insulin analogs, early on in the diagnostic process.

Topics: C-Peptide; Diabetes Mellitus; Factitious Disorders; Humans; Hypoglycemia; Insulin; Pancreatic Neoplasms

Topics: Adult; Biomarkers; C-Peptide; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Factitious Disorders; Female; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Kidney Transplantation; Pancreas Transplantation; Predictive Value of Tests; Recurrence; Self Medication; Treatment Outcome

Topics: Autoimmune Diseases; C-Peptide; Diabetes Mellitus, Type 1; Factitious Disorders; Humans; Hypoglycemia; Insulin Antibodies; Insulin Resistance; Insulin-Secreting Cells

A 36-year-old woman without significant medical history complained of "spells" of diplopia, fatigue, and dizziness. On formal fasting, her glucose dropped to 40 mg/dL, with simultaneous insulin levels of 15 microU/mL (normal <6 microU/mL) and C-peptide of 2.5 ng/ml (normal <2 ng/mL). An isolated plasma sulfonylurea screen done during the fast was positive for tolbutamide, suggesting the diagnosis of factitious hypoglycemia, but further workup revealed multiple pancreatic masses resulting in an eventual diagnosis of multiple insulinomas that was confirmed surgically. We discuss the approach to hypoglycemia caused by insulin excess and distinguishing clinical and biochemical features.

Topics: Adult; Blood Glucose; C-Peptide; Diagnosis, Differential; Factitious Disorders; Female; Humans; Hypoglycemia; Insulin; Insulinoma; Pancreatic Neoplasms; Sick Role

3 patients with recurrent, symptomatic hypoglycemia associated with increased insulin and C-peptide blood levels are described. 2 men aged 37 and 21-years had mental and social problems and although they had access to sulfonylurea drugs, both denied intake. 1 was scheduled for pancreatectomy, but as a result of the vigilance of the surgeon, the operation was canceled. By demonstrating sulfonylurea in their urine, a definitive diagnosis of factitious hypoglycemia was established, and further invasive procedures were avoided. The third was a woman aged 40-years had malignant insulinoma with liver metastases, proven by cytology. The common and differentiating clinical and laboratory characteristics of hypoglycemia due to insulinoma and factitious hypoglycemia secondary to sulfonylurea intake are discussed, and the importance of urine analysis demonstrating the presence of sulfonylurea is emphasized.

Topics: Adult; C-Peptide; Diagnosis, Differential; Factitious Disorders; Female; Humans; Hypoglycemia; Insulin; Insulinoma; Male; Mental Disorders; Pancreatic Neoplasms; Sulfonylurea Compounds

In this paper the Authors describe a case of factitious hypoglycemia in a 30-year-old nurse who came to the practitioner saying she was drug-addict. A careful history and the clinical examinations showed that the symptoms were due to hypoglycemic episodes. The finding of high plasma insulin levels together with low plasma C-peptide concentrations enabled us to exclude organic causes of hypoglycemia, suggesting the diagnosis of factitious hypoglycemia. After the patient was told we suspected a case of factitious hypoglycemia, the symptoms disappeared.

Topics: Adult; Blood Glucose; C-Peptide; Factitious Disorders; Female; Humans; Hypoglycemia; Insulin; Nursing Assistants

Ten patients had factitious hypoglycemia due to surreptitious insulin injections diagnosed and were followed for up to 15 years (median, 5 years; range, 2 months to 15 years). When available, demonstration of anti-insulin antibodies was the most helpful diagnostic test. Decreased plasma C-peptide levels corroborated the diagnosis. Young women (nine of ten) with knowledge of the medical profession or relatives with diabetes mellitus predominated in the sample. Five of the patients had a history of insulin-requiring diabetes mellitus. Two patients eventually committed suicide despite the best efforts at therapy. Only three of ten patients made a successful transition into productive life after the diagnosis of factitious hypoglycemia was established. Factitious hypoglycemia remains a difficult diagnosis to make, and the long-term outcome after the diagnosis is established is unpredictable. All efforts have to be made to confirm the diagnosis before the patients are approached. The confrontation is to be made by an experienced team of health care professionals who have gained the patient's confidence through an understanding but firm manner. Long-term therapy must be planned and initiated before the patient's discharge.

Topics: Adult; C-Peptide; Factitious Disorders; Female; Follow-Up Studies; Humans; Hypoglycemia; Insulin; Insulin Antibodies; Male

Surreptitious self-administration of insulin is an important cause of hypoglycemia. A 28-year-old female hospital ward clerk presented with hypoglycemia associated with an elevated plasma insulin level and a low plasma C-peptide concentration. Factitious illness was denied by the patient until it was definitively proven by using a species-specific insulin radioimmunoassay that the type of insulin circulating at the time of hypoglycemia was of animal rather than of human origin. The differential diagnosis of hypoglycemia associated with hyperinsulinemia and the current laboratory methods which may be employed to distinguish between factitious hypoglycemia and endogenous hyperinsulinism are discussed.

Topics: Adult; Animals; Blood Glucose; C-Peptide; Diagnosis, Differential; Factitious Disorders; Female; Humans; Hyperinsulinism; Hypoglycemia; Insulin; Radioimmunoassay; Species Specificity; Sulfonylurea Compounds

Factitious hypoglycemia is similar in presentation to insulinoma and occurs most commonly in persons with ready access to insulin. Diagnosis previously was based on circumstantial evidence but now can be confirmed by demonstration of high insulin levels and low C-peptide levels in the presence of hypoglycemia. Treatment is primarily psychiatric, and success so far is limited.

Topics: Adult; Blood Glucose; C-Peptide; Factitious Disorders; Female; Humans; Hypoglycemia; Insulin; Middle Aged; Self Administration; Substance-Related Disorders

An unusual case of factitious hypoglycaemia is described. The distinction between exogenous and endogenous hyperinsulinism is illustrated.

Topics: Adult; C-Peptide; Diabetic Ketoacidosis; Factitious Disorders; Humans; Hypoglycemia; Insulin; Male; Rural Population; South Africa

Two cases of hyperinsulinism from insulin self-administration are described, both patients being admitted to hospital with a diagnosis of insulinoma. In the first case, the diagnosis was clarified after a left pancreatectomy elsewhere, thanks to the discovery of a bottle of insulin. In the second case, the diagnosis was confirmed by the measurement of C-peptide during a hypoglycemic attack. The simultaneous sharp decrease in glucose levels, an exceptional increase in insulinaemia and a reduction or disappearance of serum C-peptide is indicative of this particular type of hyperinsulinism. The two cases described here were remarkably similar. Apart from the most common features, both reported a severe hypoglycemic syndrome of recent onset; negative tolbutamide and calcium tests; a frequent relapse shortly after glucose administration.

Topics: Adult; Blood Glucose; C-Peptide; Diagnosis, Differential; Factitious Disorders; Female; Humans; Hyperinsulinism; Hypoglycemia; Insulinoma; Munchausen Syndrome; Pancreatic Neoplasms; Recurrence; Self Administration

Topics: Adult; C-Peptide; Diagnosis, Differential; Factitious Disorders; Glyburide; Humans; Hypoglycemia; Insulin; Insulinoma; Male; Pancreatic Neoplasms; Peptides