[Factitious hypoglycemia : "a never-ending story"?] / Hypoglycémie factice : quand l'histoire se répète.

Our team of diabetologist is challenged by the case of a 41 year-old woman with recurrent hypoglycaemic episodes. Her clinical background was complex with, among others, a neuroendocrine tumor, a nonalcoholic steatohepatitis and an adrenal insufficiency; these conditions require the exploration of several potential causes. After excluding an endogenous etiology, a factitious hypoglycemia was quicky suspected by clinicians. However, several venous samples showed normal insulinemia and a moderately decreased C-peptide. After multidisciplinary team discussion and facing a strong clinical suspicion, samples were sent to another laboratory to confirm the insulin results. Substantially supratherapeutics insulin concentrations were highlighted. This confirms the previous suspicion of surreptitious insulin administration with a recombinant form unrecognized by our routinely used analyzer. This observation leads us to briefly discuss the lack of cross-reactivities observed with many different insulin assays.

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.

'Watered down' renal colic: using tap water mixed with blood to simulate macroscopic haematuria.

Renal colic is a frequent presentation to the emergency department. Although most cases are genuine, up to 0.6% of cases are factitious, representing attempts to procure parenteral narcotic medication or rarely, to attain unnecessary investigation or invasive treatment. Urethral catherization has been recommended to procure an untampered urine sample, but is viewed as invasive. Calculi analysis has no relevance to acute management. We report a case of factitious renal colic which was definitively proven to be so using sample biochemistry to confirm a tap water sample contaminated with blood. This is diagnostically useful if tap water or normal saline is used to produce an alleged urine sample.

Utility of plasma free metanephrines in diagnosis of factitious pheochromocytoma.

OBJECTIVE: To report a case of epinephrine-induced factitious pheochromocytoma in a young woman with a past medical history of Conn's syndrome. METHODS: We present a case report with clinical and laboratory details, review related reports in the literature, and demonstrate the usefulness of plasma free metanephrine levels in facilitating the diagnosis of factitious pheochromocytoma. RESULTS: A 34-year-old woman was admitted to our hospital for confirmation and localization of an occult pheochromocytoma. After thorough investigation, we discovered that the patient was surreptitiously injecting epinephrine in order to induce symptoms and signs consistent with a pheochromocytoma. Analysis of the patient's biochemical profile during and between her catecholaminergic crises revealed plasma epinephrine and free metanephrine levels that would be highly unusual for a patient with a pheochromocytoma. CONCLUSION: This case illustrates the utility of implementing the ratio of plasma epinephrine to free metanephrine levels in distinguishing factitious from organic pheochromocytoma.

[Differences in insulin secretion facilitate the differential diagnosis of insulinoma and factitious hypoglycaemia]. / Unterschiede im Insulin-Sekretionsverhalten erleichtern die Differentialdiagnose von Insulinom und Hypoglycaemia factitia.

HISTORY: A 33-year-old female nurse (married; two children; BMI 30.9 kg/m2) had recurrent episodes of symptomatic hypoglycaemia over some months. INVESTIGATIONS: Two fasting tests were terminated after 26 hours because the patient became unconscious. Improved insulin/glucose ratio was infinity and 6.1 [mU/l]/[mg/dl] (normal value < 0.5). An hyperinsulinaemic-hypoglycaemic angle "clamp test" produced a C-peptide suppression to minimally 0.26 - 0.38 nmol/l (normal value 0.06 +/- 0.01 nmol). There was no spontaneous or paradoxical burst in insulin or C-peptide concentration after either the fasting or the "clamp test". Serum analysis of sulphonylurea on several occasions documented an increase of glibenclamide above therapeutic range. TREATMENT AND COURSE: The patient denied any intake of oral antidiabetic preparations, but there were no further hypoglycaemia attacks in subsequent months. DIAGNOSIS: The demonstration of sulphonylurea in serum confirmed the diagnosis of factitious hypoglycaemia. CONCLUSION: With regard to insulin or C-peptide suppression, the results of the fasting and clamp tests are the same in factitious hypoglycaemia and insulinoma. However, under the influence of sulphonylurea drugs there are no insulin or C-peptide bursts so typical of insulinoma. In case of doubt, detection of sulphonylurea preparations in serum or urine is the only reliable way of diagnosing factitious hypoglaema due to the ingestion of sulphonylurea.

[Elevated hormone levels without endocrinopathy: hypercortisoluria and hypoglycemia as facticious disorders]. / Hormonale overmaat zonder endocrinopathie: hypercortisolurie en hypoglykemie als nagebootste stoornissen.

A 29-year-old female patient with weight gain and intermittent hypertension was suspected of having Cushing's syndrome due to conspicuous hypercortisoluria. Specific laboratory tests demonstrated that the urine samples contained prednisolone, which had resulted in a false positive elevation of urine-free cortisol measurements. The patient admitted to having taken prednisolone tablets and also to having added them to several urine collections. In a 21-year-old male patient with unexplained hypoglycaemia, hypoglycaemia was recorded during a 72-hour fast together with an elevated level of plasma insulin and a low level of plasma C-peptide. The presence of insulin autoantibodies could be excluded, making a diagnosis of factitious hypoglycaemia highly likely. Both patients were confronted with the factitious disorder and received psychiatric counselling, after which no further problems arose. Where excessive hormone levels occur, the possibility of a factitious disorder needs to be considered. In such cases, specific supplementary laboratory tests may prove helpful.

Insulinoma masquerading as factitious hypoglycemia.

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.

Case report: factitious hypoglycemia in diabetic patients.

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.

High performance liquid chromatography used to distinguish the autoimmune hypoglycemia syndrome from factitious hypoglycemia.

Recurrent episodes of spontaneous hypoglycemia developed in a 30-yr-old woman who had received a brief course of insulin therapy 10 yr previously. She denied surreptitious insulin administration, and the autoimmune hypoglycemia syndrome was considered. Her insulin levels could not be reliably measured because of the presence of circulating antiinsulin antibodies, which interfere with standard RIA techniques. Reverse phase high performance liquid chromatographic analysis of serum obtained during a hypoglycemic episode revealed a mixture of beef and pork insulins but no human insulin, firmly establishing the diagnosis of factitious hypoglycemia. This case illustrates the value of reverse phase high performance liquid chromatography in characterizing patients in whom the autoimmune hypoglycemia syndrome is suspected.

Factitious Cushing's syndrome.

A woman with pituitary-dependent Cushing's disease remained hypercortisolemic after bilateral adrenalectomy. A search for an adrenal remnant by venous catheterization study suggested persistent cortisol-secreting tissue in the left adrenal bed. During ACTH stimulation, plasma corticosterone concentrations remained low and cortisol remained high, suggesting the cortisol was of exogenous origin. Cushingoid features resolved after confronting the patient with this evidence. Plasma corticosterone concentrations played a novel role in the diagnosis of factitiously induced Cushing's syndrome in this patient.