Hypoglycemia: factitious and felonious

Insulin murder and the case of Colin Norris

Although insulin is an essential medicine and a life-saving drug, it has also been incriminated in many poisoning deaths; accidental, suicidal and some with malicious intent. Overdosing with insulin precipitates a life-threatening state of hypoglycemia and if untreated leads to coma, irreversible brain damage and death. Normally, the pancreatic β-cells secrete equimolar amounts of insulin and C-peptide into the portal venous blood, although under physiological conditions the plasma concentration ratio (insulin/C-peptide) is less than unity, because insulin is more susceptible to hepatic first-pass metabolism. A high ratio of insulin/C-peptide in plasma from a poisoned patient is compelling evidence that pharmaceutical insulin was administered, which does not contain C-peptide. The analysis of insulin and C-peptide was traditionally done by immunoassay methods (RIA and/or ELISA), although high resolution LC-MS/MS is more suitable for forensic purposes and permits the identification of insulin analogues. Use of insulin as a murder weapon is exemplified by the case of Colin Norris, a male nurse found guilty of murdering four elderly patients and the attempted murder of a fifth by injecting them with insulin. However, the prosecution evidence against Norris was mainly circumstantial and hearsay. Toxicological evidence against Norris consisted of a high insulin/C-peptide concentration ratio in plasma from one of the victims. This analysis was done by an immunoassay method at a clinical laboratory and not a forensic laboratory. Analytical procedures, including chain-of-custody routines, are more stringent at forensic laboratories. Since his conviction, some of the medical evidence against Norris has been called into question, especially the prevalence of spontaneous attacks of hypoglycemia in elderly and frail patients with co-morbidities.

Attempted Murder of a Young Child Followed by an Attempted Suicide of the Mother by Injection of Insulin Aspart: Identification of Quantification of Insulin by LC-HRMS and UPLC-MS/MS in Blood of the Two Cases

The identification and quantification of insulin and its analogues have always been a challenge in the forensic field. Murder, suicide attempts and induced hypoglycemia in the context of factitious disorders have been described with the use of synthetic analogues of human insulin. There is very few information in the literature about aspart insulin concentrations in overdose cases. In this paper, we present a case of a nurse who tried to murder her 10-year-old daughter by injecting her aspart insulin and who, later, tried to commit suicide by injecting herself the same hormone. Two empty syringes and a FIASP ® Flextouch pen were found in the woman's apartment. A LC-HRMS method was developed in order to identify and discriminate aspart insulin from human insulin in blood samples as well as in syringes and pen, while an LC-MS/MS method was developed for the quantification of insulin in blood samples. Aspart insulin tested positive at 5.7 and 2.4 ng/mL in the blood specimens of the mother and the child, respectively. The contents of the syringes and pen also corresponded to aspart insulin. Although the mother claims to have injected an overdose of aspart insulin, the concentrations found were in the therapeutic range for subjects under therapy. Due to the high instability of insulin and the long time elapsed between sampling and forensic analysis (8 months) due to administrative reasons, the concentration at the time of collection was probably much higher. In this case, it was possible to identify aspart insulin and discriminate it from human insulin in a context of attempted murder and subsequent attempted suicide using high-resolution mass spectrometry, which is of paramount importance in forensic medicine.

Development of a new GC-MS/MS method for the determination of metformin in human hair

Diabetes mellitus is one of the most important public health challenges. Metformin (1,1-dimethylbiguanide) represents the "gold standard" for the treatment of diabetes mellitus type 2. Despite its important role in reducing mortality and morbidity in the diabetic population, metformin is associated with an increased risk of stroke. To document exposure to a drug, hair is considered to be the specimen of choice to complement blood and urine, since it provides historical detail of a subject's chronic exposure to drug(s). Measuring hair concentration of metformin can be important for forensic toxicologists investigating criminal poisoning or Munchausen's syndrome by proxy. In clinical toxicology, drug monitoring using hair to document metformin observance has not yet been described. To document the interest of hair analysis for metformin, the authors have developed and validated a method using a gas-chromatography tandem mass spectrometry system and applied it to authentic hair obtained from 9 diabetic patients under daily treatment. The validation procedure demonstrated a LOD an LOQ of 1 and 100 pg/mg, respectively and acceptable linearity, repeatability and reproducibility. The hair of the 9 patients tested positive in the low ng/mg range with concentrations ranging from 0.3 to 3.8 ng/mg. It seems obvious, in comparison with other drugs, that metformin is badly incorporated into hair, as the daily dosage varied from 1 to 3 g. Although limited in the number of subjects, the study allowed to postulate a possible correlation between daily dose and concentration in dark hair, while for light hair no correlation was found.

Insulin Autoimmune Syndrome (Hirata Disease): A Comprehensive Review Fifty Years After Its First Description

Insulin autoimmune syndrome (IAS), also named Hirata's disease, is a rare condition characterized by hypoglycemic episodes due to the presence of high titers of insulin autoantibodies (IAA). IAS is a form of immune-mediated hypoglycemia, which develops when a triggering factor (ie, a medication or a viral infection) acts on an underlying predisposing genetic background. IAS pathogenesis involves the formation of insulin-IAA complexes that induce glycemic alterations with a double-phase mechanism: IAA prevent insulin to bind its receptor in the postprandial phase, possibly resulting in mild hyperglycemia; thereafter, insulin is released from the complexes irrespective of blood glucose concentrations, thus inducing hypoglycemia. The diagnosis of IAS is challenging, requiring a careful workup aimed at excluding other causes of hyperinsulinemic hypoglycemia. The gold standard for the definitive diagnosis is the finding of IAA in a blood sample. Because IAS is frequently a self-remitting disease, its management mostly consists of supportive measures, such as dietary modifications, aimed at preventing the development of hypoglycemia. Pharmacological therapies may occasionally be necessary for patients presenting with severe manifestations of IAS. Available therapies may include drugs that reduce pancreatic insulin secretion (somatostatin analogues and diazoxide, for instance) and immunosuppressive agents (glucocorticoids, azathioprine and rituximab). The purpose of this review is to provide a comprehensive analysis of the disease, by describing the burden of knowledge that has been obtained in the 50 years following its first description, took in 1970, and by highlighting the points that are still unclear in its pathogenesis and management.

A case report of type 1 diabetes mellitus and factitious hypoglycemia in a patient with Munchausen Syndrome

Munchausen syndrome is rarely considered as a first diagnosis, especially in a type 1 diabetic patient presenting with hyperinsulinemic hypoglycemia. The diagnosis should be considered when episodes of hypoglycemia are persistent, and tests suggest a possible exogenous source of insulin. We report a case of a 26-year-old man with multiple hypoglycemic episodes and a long known diagnosis of diabetes type 1 who was referred to our institution after multiple in and out patient consultations in other institutions. He arrived with persistent hypoglycemia, even after withdrawal of insulin therapy on medical record, but persistent self-administration and misuse, without health care professional knowledge, of insulin therapy. He was diagnosed with factitious hypoglycemia after psychiatric evaluation. The patient improved with psychotherapy and family support as well as strict vigilance of insulin administration.

Role of the Entero-Insular Axis in the Pathogenesis of Idiopathic Reactive Hypoglycemia: A Pilot Study

CONTEXT

Idiopathic reactive hypoglycemia (IRH) is characterized by recurrent episodes of symptomatic hypoglycemia occurring within 4 hours after meals. The underlying mechanisms remain obscure.

OBJECTIVE

This study aimed to investigate the response of the glucoregulatory and gastrointestinal hormones to an oral glucose load (OGTT) in individuals with documented IRH.

DESIGN AND SETTING

This was a cross-sectional study composed of outpatients referred to "Federico II" University of Naples.

PATIENTS

We enrolled subjects with IRH documented by a mixed meal under ordinary life conditions and healthy subjects as controls.

MAIN OUTCOME MEASURE

We measured plasma glucose, insulin, glucagon-like peptide 1 (GLP-1), GIP, and glucagon response to a 75-g OGTT in cases and controls.

RESULTS

Ten IRH and eight control subjects were enrolled. During the OGTT, mean plasma glucose tended to be lower in IRH than in control subjects, reaching a statistically significant difference at 240 minutes (T240) (43 ± 1.6 vs 72 ± 0.3 mg/dL; P = .001). Accordingly, the insulin response was higher in IRH than in control subjects (P < .019) with a statistically significant difference (46%) at T90 (P = .045) and was associated with significantly lower glucagon levels in the late phase of the OGTT: at T120 (P = .031) and T180 (P = .048) in IRH than in control subjects. A greater GLP-1 response was found among IRH compared with control subjects (P = .005); GLP-1 peak was 2-fold higher in IRH individuals (9.77 ± 2.52 pmol/L) than in the control group (4.19 ± 0.53 pmol/L; P = .041). In the IRH group, GLP-1 peak inversely correlated with the nadir of plasma glucose (r = -0.66; P = .039). A multivariate analysis confirmed that GLP-1 peak independently predicted the plasma glucose nadir (β = -0.593; P = .026).

CONCLUSIONS

GLP-1 may play a significant role in the pathogenesis of idiopathic IRH.

Hypoglycemia after Roux-En-Y gastric bypass: detection rates of continuous glucose monitoring (CGM) versus mixed meal test

BACKGROUND

Neuroglucopenic hypoglycemia might be an underestimated threat for roux-en-Y gastric bypass (RYGB) patients leading to fatigue, syncope, seizures or even accidental deaths. Different measurements can assess hypoglycemia such as a finger-stick glucometer, an Oral Glucose Tolerance Test, a Mixed Meal-Test (MMT) or, as introduced recently, continuous glucose monitoring (CGM).

SETTING

University Hospital, Austria.

METHODS

To assess the incidence of hypoglycemic episodes under real life conditions, 5-day CGM was performed in a series of 40 patients at a mean of 86 months after RYGB. The detection rates were compared to a mixed meal-test.

RESULTS

CGM detected hypoglycemic episodes of <55 mg/dL or <3.05 mmol/L in 75% of the patients, while MMT indicated hypoglycemia in 29% of the patients. CGM also detected nocturnal hypoglycemic episodes in 15 (38%) of the patients. A mean of 3±1 hypoglycemic episodes per patient with a mean duration of 71±25 minutes were observed by CGM.

CONCLUSIONS

Assessed under real life conditions by CGM, post-RYGB hypoglycemia was found more frequently than expected. CGM revealed hypoglycemic episodes in 75% of the patients while MMT had a lower detection rate. Thus, CGM may have a role for screening but also for the evaluation of dietary modifications, drug therapy or surgical intervention for hypoglycemia after RYGB.

Approach to the patient with spontaneous hypoglycemia

Hypoglycemia is common in daily clinical practice and often occurs during the treatment of diabetes mellitus. However, a small minority of hypoglycemia encountered in clinical practice is spontaneous and thus not induced by glycemic lowering agents. These spontaneous hypoglycemic events confront the clinician with a diagnostic enigma. Although the trained clinician can recognize the autonomic and neuroglycopenic symptoms of hypoglycemia even in a patient not on insulin, it remains challenging to decipher the etiology of a spontaneous hypoglycemic event. A logical and stepwise approach to the spontaneous hypoglycemic event allows for a conclusive diagnosis. This diagnostic process consists of adequately diagnosing hypoglycemia by fulfilling Whipple's triad, stratifying patients according to their clinical status and analyzing a full hypoglycemic blood panel. A complete hypoglycemic blood panel should include the analysis of glucose, insulin, C-peptide, pro-insulin, insulin antibodies and the presence of oral hypoglycemic agents. For patients with episodes of hypoglycemia induced by excessive endogenous insulin, additional imaging is often required to detect the presence of an underlying insulinoma. By diagnosing the underlying cause of the spontaneous hypoglycemia, the physician also diagnosis the mechanism by which the hypoglycemic event occurs. Allowing for a problem orientated therapeutic approach.

METHODOLOGY

The present review is based upon a comprehensive PubMed search between 1985 and 2013. This uses search terms of spontaneous hypoglycemia, insulinoma, nesidioblastosis, insulin auto-immunity, noninsulinoma pancreatogenous hypoglycemia syndrome, hormone deficiency, pro-IGF II, and pro-insulin growth factor II, and cross reference searching of pivotal articles in the subject.

Factitious Cushing's syndrome masquerading as Cushing's disease

CONTEXT

Factitious Cushing's syndrome is extremely rare. The diagnosis is challenging as cross-reactivity of synthetic corticosteroids or their metabolites in immunoassay measurements of plasma or urinary cortisol can make distinguishing between true and factitious Cushing's syndrome difficult. Adrenocorticotropin (ACTH) is usually suppressed in factitious Cushing's syndrome.

PATIENT

A 54-year-old woman presented with clinical and biochemical features of Cushing's syndrome and an unsuppressed ACTH concentration. She denied recent exogenous corticosteroid use.

INVESTIGATIONS AND RESULTS

Initial investigations revealed a markedly elevated urinary free cortisol, mildly elevated midnight salivary cortisol and normal morning cortisol concentration. Plasma ACTH was not suppressed at 13 ng/l (RR 10-60 ng/l). A pituitary MRI was normal, but inferior petrosal sinus sampling (IPSS) revealed a post corticotrophin releasing hormone ACTH ratio >20:1 in the left petrosal sinus. Ketoconazole therapy amplified discordance between the urinary free and morning plasma cortisol concentrations. Further investigation of this discordance using high-pressure liquid chromatography tandem mass spectrometry (HPLC-MS/MS) revealed a urinary free cortisol excretion of only 20 nmol/24 h, but prednisolone excretion of 16,200 nmol/24 h.

CONCLUSIONS

Factitious Cushing's syndrome can mimic endogenous ACTH-dependent hypercortisolism during initial investigations and IPSS. This case highlights the importance of (i) recognizing the significance of discordant results; (ii) using an ACTH assay capable of reliably differentiating ACTH-dependent from ACTH-independent Cushing's syndrome; and (iii) appreciating that IPSS is only useful to localize the source of ACTH in confirmed ACTH-dependent Cushing's syndrome. In this case, measurement of corticosteroids by HPLC-MS/MS was essential in reaching the correct diagnosis.

Postmortem chemistry update part I

Postmortem chemistry is becoming increasingly essential in the forensic pathology routine and considerable progress has been made over the past years. Biochemical analyses of vitreous humor, cerebrospinal fluid, blood and urine may provide significant information in determining the cause of death or in elucidating forensic cases. Postmortem chemistry may essentially contribute in the determination of the cause of death when the pathophysiological changes involved in the death process cannot be detected by morphological methods (e.g. diabetes mellitus, alcoholic ketoacidosis and electrolytic disorders). It can also provide significant information and useful support in other forensic situations, including anaphylaxis, hypothermia, sepsis and hormonal disturbances. In this article, we present a review of the literature that covers this vast topic and we report the results of our observations. We have focused our attention on glucose metabolism, renal function and electrolytic disorders.

Guidelines and recommendations for laboratory analysis in the diagnosis and management of diabetes mellitus

BACKGROUND

Multiple laboratory tests are used to diagnose and manage patients with diabetes mellitus. The quality of the scientific evidence supporting the use of these tests varies substantially.

APPROACH

An expert committee compiled evidence-based recommendations for the use of laboratory testing for patients with diabetes. A new system was developed to grade the overall quality of the evidence and the strength of the recommendations. Draft guidelines were posted on the Internet and presented at the 2007 Arnold O. Beckman Conference. The document was modified in response to oral and written comments, and a revised draft was posted in 2010 and again modified in response to written comments. The National Academy of Clinical Biochemistry and the Evidence-Based Laboratory Medicine Committee of the American Association for Clinical Chemistry jointly reviewed the guidelines, which were accepted after revisions by the Professional Practice Committee and subsequently approved by the Executive Committee of the American Diabetes Association.

CONTENT

In addition to long-standing criteria based on measurement of plasma glucose, diabetes can be diagnosed by demonstrating increased blood hemoglobin A(1c) (HbA(1c)) concentrations. Monitoring of glycemic control is performed by self-monitoring of plasma or blood glucose with meters and by laboratory analysis of HbA(1c). The potential roles of noninvasive glucose monitoring, genetic testing, and measurement of autoantibodies, urine albumin, insulin, proinsulin, C-peptide, and other analytes are addressed.

SUMMARY

The guidelines provide specific recommendations that are based on published data or derived from expert consensus. Several analytes have minimal clinical value at present, and their measurement is not recommended.

Guidelines and recommendations for laboratory analysis in the diagnosis and management of diabetes mellitus

BACKGROUND

Multiple laboratory tests are used to diagnose and manage patients with diabetes mellitus. The quality of the scientific evidence supporting the use of these tests varies substantially.

APPROACH

An expert committee compiled evidence-based recommendations for the use of laboratory testing for patients with diabetes. A new system was developed to grade the overall quality of the evidence and the strength of the recommendations. Draft guidelines were posted on the Internet and presented at the 2007 Arnold O. Beckman Conference. The document was modified in response to oral and written comments, and a revised draft was posted in 2010 and again modified in response to written comments. The National Academy of Clinical Biochemistry and the Evidence Based Laboratory Medicine Committee of the AACC jointly reviewed the guidelines, which were accepted after revisions by the Professional Practice Committee and subsequently approved by the Executive Committee of the American Diabetes Association.

CONTENT

In addition to long-standing criteria based on measurement of plasma glucose, diabetes can be diagnosed by demonstrating increased blood hemoglobin A(1c) (Hb A(1c)) concentrations. Monitoring of glycemic control is performed by self-monitoring of plasma or blood glucose with meters and by laboratory analysis of Hb A(1c). The potential roles of noninvasive glucose monitoring, genetic testing, and measurement of autoantibodies, urine albumin, insulin, proinsulin, C-peptide, and other analytes are addressed.

SUMMARY

The guidelines provide specific recommendations that are based on published data or derived from expert consensus. Several analytes have minimal clinical value at present, and their measurement is not recommended.

Murder by insulin: suspected, purported and proven-a review

Murder by insulin-whether attempted, suspected or proven-is rare. Only 66 cases worldwide could be found for this review. A conviction was secured in 31 cases and additional weapon was employed in 11. Differentiation of attempted homicide from Munchausen syndrome by proxy in the young and from 'mercy killing' in the elderly was not attempted. Most perpetrators were close relatives and most victims were alive when discovered and responded to treatment. Hypoglycaemia is the first clue to homicidal insulin use in living subjects and requires the demonstration of a plasma insulin concentration of generally more than 1000 pmol/L and undetectable plasma C-peptide concentration to establish the diagnosis. Serum glucose measurements are valueless in victims found dead. The presence near the body of insulin vials, syringes or needles, loose talk by the suspected perpetrator or their ready access to insulin may be the only clue. The demonstration of insulin in tissue around an injection site by immunohistopathology or by measuring it in an extract clinches the diagnosis. Immunoassays suitable for clinical use to detect and measure insulin and C-peptide are subject to random errors and cannot be relied upon unless special precautions including separation by gel filtration or HPLC are undertaken prior to analysis. They do not detect or measure accurately a new generation of synthetic insulin analogues. Mass spectrometry will be required to do this and to validate clinical immunoassays, upon which convictions have always had to rely in the past.

Evaluation and management of adult hypoglycemic disorders: an Endocrine Society Clinical Practice Guideline

OBJECTIVE

The aim is to provide guidelines for the evaluation and management of adults with hypoglycemic disorders, including those with diabetes mellitus.

EVIDENCE

Using the recommendations of the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system, the quality of evidence is graded very low (plus sign in circle ooo), low (plus sign in circle plus sign in circle oo), moderate (plus sign in circle plus sign in circle plus sign in circle o), or high (plus sign in circle plus sign in circle plus sign in circle plus sign in circle).

CONCLUSIONS

We recommend evaluation and management of hypoglycemia only in patients in whom Whipple's triad--symptoms, signs, or both consistent with hypoglycemia, a low plasma glucose concentration, and resolution of those symptoms or signs after the plasma glucose concentration is raised--is documented. In patients with hypoglycemia without diabetes mellitus, we recommend the following strategy. First, pursue clinical clues to potential hypoglycemic etiologies--drugs, critical illnesses, hormone deficiencies, nonislet cell tumors. In the absence of these causes, the differential diagnosis narrows to accidental, surreptitious, or even malicious hypoglycemia or endogenous hyperinsulinism. In patients suspected of having endogenous hyperinsulinism, measure plasma glucose, insulin, C-peptide, proinsulin, beta-hydroxybutyrate, and circulating oral hypoglycemic agents during an episode of hypoglycemia and measure insulin antibodies. Insulin or insulin secretagogue treatment of diabetes mellitus is the most common cause of hypoglycemia. We recommend the practice of hypoglycemia risk factor reduction--addressing the issue of hypoglycemia, applying the principles of intensive glycemic therapy, and considering both the conventional risk factors and those indicative of compromised defenses against falling plasma glucose concentrations--in persons with diabetes.

Occult sporadic insulinoma: Localization and surgical strategy

Insulinomas continue to pose a diagnostic challenge to physicians, surgeons and radiologists alike. Most are intrapancreatic, benign and solitary. Biochemical diagnosis is obtained and imaging techniques to localize lesions continue to evolve. Surgical resection is the treatment of choice. Despite all efforts, an occult insulinoma (occult insulinoma refers to a biochemically proven tumor with indeterminate anatomical site before operation) may still be encountered. New localization preoperative techniques decreases occult cases and the knowledge of the site of the mass before surgery allows to determine whether enucleation of the tumor or pancreatic resection is likely to be required and whether the tumor is amenable to removal via a laparoscopic approach. In absence of preoperative localization and intraoperative detection of an insulinoma, blind pancreatic resection is not recommended.

Pancreatic neuroendocrine tumours

Pancreatic neuroendocrine tumours (PET) are rare neoplasms of the pancreas accounting for less than 5% of all primary pancreatic malignancies. Included in this group are insulinomas, gastrinomas, glucagonoma and somatostatinomas. Collectively these neoplasms are classified as functional PETs. Where a PET is not associated with a clinical syndrome due to hormone oversecretion, it is referred to as a non-functioning PET. Non-functioning PETs are pancreatic tumours with endocrine differentiation but lack a clinical syndrome of hormone hypersecretion. The incidence of these tumours varied between 15 and 53%. Presentation is related to the mass effect of the tumour with symptoms often non-specific. Treatment is surgical excision with chemotherapy and hormonal therapy is controversial. For functioning PETs, surgery remains the optimal therapy, however, long-term survival can be expected even in the presence of metastases. With advances in medical management, radiolabelled somatostatin therapy, hepatic arterial chemoembolisation and radiofrequency ablation, symptoms may be controlled to optimize quality of life.

Serial murder by healthcare professionals

The prosecution of Charles Cullen, a nurse who killed at least 40 patients over a 16-year period, highlights the need to better understand the phenomenon of serial murder by healthcare professionals. The authors conducted a LexisNexis search which yielded 90 criminal prosecutions of healthcare providers that met inclusion criteria for serial murder of patients. In addition we reviewed epidemiologic studies, toxicology evidence, and court transcripts, to provide data on healthcare professionals who have been prosecuted between 1970 and 2006. Fifty-four of the 90 have been convicted; 45 for serial murder, four for attempted murder, and five pled guilty to lesser charges. Twenty-four more have been indicted and are either awaiting trial or the outcome has not been published. The other 12 prosecutions had a variety of legal outcomes. Injection was the main method used by healthcare killers followed by suffocation, poisoning, and tampering with equipment. Prosecutions were reported from 20 countries with 40% taking place in the United States. Nursing personnel comprised 86% of the healthcare providers prosecuted; physicians 12%, and 2% were allied health professionals. The number of patient deaths that resulted in a murder conviction is 317 and the number of suspicious patient deaths attributed to the 54 convicted caregivers is 2113. These numbers are disturbing and demand that systemic changes in tracking adverse patient incidents associated with presence of a specific healthcare provider be implemented. Hiring practices must shift away from preventing wrongful discharge or denial of employment lawsuits to protecting patients from employees who kill.

The management of insulinoma

BACKGROUND

Insulinomas are rare tumours. Their clinical presentation, localization techniques and operative management were reviewed.

METHODS

An electronic search of the Medline, Embase and Cochrane databases was undertaken for articles published between January 1966 and June 2005 on the history, presentation, clinical evaluation, use of imaging techniques for tumour localization and operative management of insulinoma.

RESULTS AND CONCLUSION

Most insulinomas are intrapancreatic, benign and solitary. Biochemical diagnosis is obtained during a supervised 72-h fast. Non-invasive preoperative imaging techniques to localize lesions continue to evolve. Intraoperative ultrasonography can be combined with other preoperative imaging modalities to improve tumour detection. Surgical resection is the treatment of choice. In the absence of preoperative localization and intraoperative detection of an insulinoma, blind pancreatic resection is not recommended.

Criminal Poisoning: Munchausen by Proxy

The diagnosis and subsequent prosecution of Munchausen by proxy (MBP) cases require the collaborative teamwork of health care teams, laboratory personnel, law enforcement, and social services. Poisoning occurs in a significant number of the MBP cases with a diverse variety of agents used. To aid laboratory professionals in determining the appropriate toxicology tests to perform in such criminal cases, health care professionals must focus their testing requests on substances that correspond to the victim's signs, symptoms, and ancillary test values. This article reviews MBP, with particular focus on poisoning agents that have been used in past reported cases.

Factitious hyperinsulinism leading to pancreatectomy: severe forms of Munchausen syndrome by proxy

Clinical history and inappropriate insulin secretion during hypoglycemic episodes permit the diagnosis of hyperinsulinism. We report 2 cases of factitious hyperinsulinism leading to partial pancreatectomy. Case 1 was an 8-year-old girl who presented with severe hypoglycemia and elevated insulin and C-peptide levels. Catheterization of pancreatic veins was performed to localize the excess insulin secretion. Insulinoma was suspected, and partial pancreatectomy was performed. Ten days after surgery, severe hypoglycemia recurred with severely elevated plasma insulin levels (x100) but very low C-peptide plasma levels, suggesting factitious hyperinsulinemia. Hypoglycemic episodes before surgery were provoked by oral sulfonamides; postoperative episodes were caused by parenteral insulin. Falsified prescriptions for sulfonamides and insulin by the mother, a nurse, were found. Case 2 was a 6-month-old girl who presented with seizures and hypoglycemia but had a symptom-free interval of many months afterward. At 2 years of age, repeated hypoglycemic seizures and elevated insulin plasma levels suggested congenital hyperinsulinism. C-peptide plasma level, measured once, was normal, but blood sampling was performed 15 minutes after a hypoglycemic episode. Partial pancreatectomy was performed. Two weeks after surgery, hypoglycemic seizures recurred, and the patient was admitted for pancreatic vein catheterization. This investigation was performed during hypoglycemia and revealed high insulin levels and undetectable C-peptide levels, suggesting factitious hypoglycemia. Insulin/C-peptide ratio analysis is crucial to assess factitious hypoglycemia, although sulfonamide-induced hypoglycemia is not thereby detected. One percent (2 of 250) of all cases of hyperinsulinemic hypoglycemia in our unit have been identified as Munchausen syndrome by proxy. Atypical disease history should raise the question of factitious hypoglycemia.

Munchausen's syndrome presenting as severe panniculitis

Factitious disorders may trouble any physician during his/her career. A considerable number of cases of Munchausen's syndrome (self-induced disorder) are misdiagnosed in clinical practice. A 36-year-old woman was admitted to our hospital because of fever and abdominal pain. Physical examination showed signs of inflammation of the abdominal wall, and histological examination revealed severe panniculitis. We investigated various aetiologic factors that could probably be related to fat necrosis, but we found no explanation of the phenomenon until we verified the diagnosis of Munchausen's syndrome. 2 years later, the patient underwent surgery for removal of needles, which she herself had deliberately located under her skin. High index of suspicion and physician's persistence are necessary to make the correct diagnosis in the various protean manifestations of Munchausen's syndrome.

Inadvertent sulfonylurea overdosage and hypoglycemia in an elderly woman: failure of serum hypoglycemia screening

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.

The biochemical investigation of cases of hypoglycaemia: an assessment of the clinical effectiveness of analytical services

AIM

To assess the extent to which biochemical analytical services contribute to the diagnosis and management of clinical cases of hypoglycaemia.

METHODS

All cases of confirmed hypoglycaemia, referred during a six month period, were included in the survey. Questionnaires were sent to each referring laboratory requesting information on the clinical progress and current status of the patient.

RESULTS

The level of influence exerted by analytical data was assigned in each case and those with similar outcomes combined. Identifiable case groups were: (1) Results not recorded in the patients' notes (15.7%). (2) Inappropriate requesting of insulin and C peptide measurements in cases of diabetes (11.4%). (3) Patient died soon after investigation (20.0%). (4) Patient recovered spontaneously (17.1%). (5) Patient received effective medical or surgical treatment (12.9%). (6) Patient awaiting or not requiring pathology based treatment (31.4%). (7) Inconclusive outcome prompting further investigation (5.7%).

CONCLUSIONS

Within the timescale of the survey (approximately 12 months), positive progress had been made towards diagnosis and subsequent treatment in only 10% of cases. Another 30% were either awaiting some form of treatment or further diagnostic tests. The remaining 60% did not appear to benefit in any way from the biochemical investigations.

Guidelines and Recommendations for Laboratory Analysis in the Diagnosis and Management of Diabetes Mellitus

Background: Multiple laboratory tests are used in the diagnosis and management of patients with diabetes mellitus. The quality of the scientific evidence supporting the use of these assays varies substantially.

Approach: An expert committee drafted evidence-based recommendations for the use of laboratory analysis in patients with diabetes. An external panel of experts reviewed a draft of the guidelines, which were modified in response to the reviewers’ suggestions. A revised draft was posted on the Internet and was presented at the AACC Annual Meeting in July, 2000. The recommendations were modified again in response to oral and written comments. The guidelines were reviewed by the Professional Practice Committee of the American Diabetes Association.

Content: Measurement of plasma glucose remains the sole diagnostic criterion for diabetes. Monitoring of glycemic control is performed by the patients, who measure their own plasma or blood glucose with meters, and by laboratory analysis of glycated hemoglobin. The potential roles of noninvasive glucose monitoring, genetic testing, autoantibodies, microalbumin, proinsulin, C-peptide, and other analytes are addressed.

Summary: The guidelines provide specific recommendations based on published data or derived from expert consensus. Several analytes are of minimal clinical value at the present time, and measurement of them is not recommended.