Malignant Somatostatinoma Presenting with Diabetic Ketoacidosis and Inhibitory Syndrome: Pathophysiologic Considerations

ObjectiveTo describe a patient with diabetic ketoacidosis secondary to a malignant somatostatinoma.MethodsWe present the clinical, laboratory, radiologic, and pathologic findings of a patient with diabetic ketoacidosis secondary to a malignant somatostatinoma. We also review the potential effects of somatostatin on glucose homeostasis and discuss the underlying pathophysiologic mechanisms.ResultsA 30-year-old woman presented with diabetic ketoacidosis and had a malignant somatostatinoma with hepatic, bone, and lymph node metastasis. She exhibited features of somatostatinoma “inhibitory syndrome” characterized by mild nonketotic hyperglycemia, hypochlorhydria, cholelithiasis, steatorrhea, anemia, and weight loss. In these tumors, the absence of ketoacidosis is thought to arise from the somatostatin-induced simultaneous suppression of the secretion of insulin and glucagon. The patient’s primary tumor could not be located.ConclusionsDiabetic ketoacidosis may occur in somatostatinomas. The secretion of larger molecular weight forms of somatostatin from the tumor may contribute to the ketogenesis. (Endocr Pract. 2010;16:835-837)     

Cola-Induced Hypokalemia-a Case Report and Review of the Literature

ObjectiveWe aim to describe an unusual and underappreciated cause for hypokalemia.MethodsWe describe a patient diagnosed with cola-induced hypokalemia and review the literature.ResultsIngestion of massive amounts of cola can lead to severe hypokalemia through several pathophysiologic mechanisms. These perturbations include osmotic diarrhea, osmotic diuresis, and hyperinsulinemia secondary to hyperglycemia with resultant intracellular to cellular shifts in potassium. These effects are magnified by concomitant high levels of caffeine.ConclusionIngestion of large quantities of cola should be added to differential diagnosis for severe hypokalemia. (Endocr Pract. 2013;19:e21-e23)     

Severe hyperkalaemia and ketoacidosis during routine treatment with an insulin pump.

During a feasibility study of the use of insulin pumps to treat diabetes ketoacidosis occurred at a rate of 0.14 episodes/patient/year in the first year but was lower in subsequent years. A case of cardiac arrest secondary to hyperkalaemia during ketoacidosis occurred in a patient treated with a pump. The mean (SD) serum potassium concentration on presentation to hospital with ketoacidosis was significantly higher in patients treated with a pump (5.7 (1.1) mmol(mEq)/l) than those treated with conventional injections of insulin (4.9(0.9) mmol/l; p less than 0.01). The high rate of ketoacidosis and raised serum potassium concentrations during treatment with the pump creates doubt about the use of this treatment as an alternative regimen for large numbers of patients in a busy diabetic clinic.     

Diabetic Ketoacidosis—A Review of Cases at a University Medical Center

Twenty-five cases of diabetic ketoacidosis were studied retrospectively with respect to clinical characteristics and results of therapy. In this series (as with all 88 patients admitted in the last five years with a diagnosis of diabetic ketoacidosis) there were no deaths. Infection was found to be the most common precipitating event, documented by physical findings and cultures in one-third of these cases.In about two-thirds of the cases, electrocardiograms which were read as abnormal on admission reverted to normal after therapy.In all patients serum potassium levels decreased from admission values; one patient became symptomatically hypokalemic.Low serum potassium levels on admission and early vigorous bicarbonate therapy are emphasized as major predisposing factors of symptomatic hypokalemia. None of the patients had overt hyperosmolar coma, lactic acidosis or cerebral edema during therapy.     

INTRAVENOUS NUTRITION—A Clinical Evaluation of a 50 Per Cent Dextrose in Water Solution,Containing 1 mg. of Hydrocortisone per 100 ml

A 50 per cent dextrose in water solution, containing 1 mg. of hydrocortisone per 100 ml., was used successfully in 70 patients for intravenous nutritional maintenance and repletion. There were no adverse systemic effects during or following 216 infusions. The only undesirable local reaction was the rare occurrence of pain in the arm when the concentrated solutions were given too rapidly. Glycosuria was minimal if the infusion rate did not exceed 0.85 gm. of glucose per kilogram of body weight per hour, particularly if 50 units of insulin were added to each 550 ml. bottle of 50 per cent dextrose. In patients without significantly elevated serum potassium content, 30 mEq. of potassium chloride, acetate or phosphate was added to each bottle to prevent hypokalemia.Preliminary observations suggest that this new solution may be given safely intravenously, without need for cutdowns or plastic catheters, if the needle is carefully inserted and well immobilized in the arm vein and the duration of the infusion is not too prolonged. Further studies on the effect of such high caloric supplementation plus protein hydrolysates in parenteral nutritional repletion and maintenance are indicated.     

Venous Serum Bicarbonate Concentration Predicts Arterial pH in Adults with Diabetic Ketoacidosis

ObjectiveThe initial assessment of metabolic acidosis in subjects with diabetic ketoacidosis (DKA) is arterial blood gas analysis. This process is expensive, painful, and technically difficult. Furthermore, blood gas analysis may not be available in some facilities, especially in developing countries where DKA-associated morbidity and mortality remain high. Therefore, we investigated the utility of venous bicarbonate concentration obtained from a basic metabolic panel in predicting arterial pH in adults with DKA.MethodsWe performed a retrospective analysis of clinical and biochemical data of 396 adults admitted to 2 community teaching hospitals with DKA. We determined the correlation between arterial pH and venous serum parameters. Using multiple logistic regression, we obtained a predictive formula for arterial pH from serum venous bicarbonate level.ResultsThe patient population was 59.0% male and had a mean age of 36.7 ± 13.3 years. We derived that arterial pH = 6.97 + (0.0163 × bicarbonate), and by applying this equation, we determined that serum venous bicarbonate concentration of ≤ 20.6 mEq/L predicted arterial pH ≤ 7.3 with over 95% sensitivity and 92% accuracy.ConclusionVenous serum bicarbonate obtained from the basic metabolic panel is an affordable and reliable way of estimating arterial pH in adults with DKA. Validation of this formula in a prospective study would offer a more accessible means of estimating metabolic acidosis in adults with DKA, especially in developing countries where DKA incidence and mortality remain high. (Endocr Pract. 2014;20:201-206)     

Hyperkalemia Develops in Some Thyroidectomized Patients Undergoing Thyroid Hormone Withdrawal in Preparation for Radioactive Iodine Ablation for Thyroid Carcinoma

Objective: Hyponatremia is observed in hypothyroidism, but it is not known if hypo- or hyperkalemia is associated with hypothyroidism. To study these questions, we determined serum potassium (K⁺) levels in thyroidectomized patients undergoing levothyroxine withdrawal before radioactive iodine (RAI) therapy for thyroid carcinoma.Methods: We retrospectively studied the records of 108 patients who had undergone total thyroidectomy for thyroid carcinoma followed by levothyroxine withdrawal and then ablation with RAI at Nagasaki University Hospital from 2009–2013. Blood samples were analyzed for serum K⁺ concentrations when patients were euthyroid just before levothyroxine withdrawal and hypothyroid 21 days after levothyroxine withdrawal. We determined the proportion of patients who developed hyperkalemia (K⁺ ≥5 mEq/L) and hypokalemia (K⁺ ≤3.5 mEq/L).Results: Five (4.6%) patients developed hyperkalemia and 2 (1.9%) patients developed hypokalemia after levothyroxine withdrawal. The mean serum K⁺ level after levothyroxine withdrawal was significantly higher than before levothyroxine withdrawal (4.23 ± 0.50 mEq/L vs. 4.09 ± 0.34 mEq/L; P<.001). After levothyroxine withdrawal, serum K⁺ values were significantly correlated with age, serum sodium and creatinine levels, and the estimated glomerular filtration rate but not with serum free thyroxine or thyroid-stimulating hormone concentrations. The finding of an elevated serum K⁺ of >0.5 mEq/L after levothyroxine withdrawal was more prevalent with age >60 years (odds ratio [OR], 4.66; P = .026) and with the use of angiotensin-II receptor blockers or angiotensin-converting enzyme inhibitors (OR, 3.53; P = .033) in a multivariate analysis.Conclusion: Hyperkalemia develops in a small percentage of hypothyroid patients after thyroid hormone withdrawal, especially in patients over 60 years of age who are using antihypertensive agents that inhibit the reninangiotensin- aldosterone system.Abbreviations: ACE-I = angiotensin-converting enzyme inhibitor ARB = angiotensin-II receptor blocker Cr = creatinine eGFR = estimated glomerular filtration rate Eu-K⁺ = serum level of K⁺ in the euthyroid state Hypo-K⁺ = serum level of K⁺ in the hypothyroid state K⁺ = potassium Na⁺ = sodium ?K⁺ = Hypo-K⁺ value minus Eu-K⁺ value RAI = radioactive iodine TSH = thyroid-stimulating hormone     

Excess Thyroid Hormone and Carbohydrate Metabolism

ObjectiveTo review the pertinent basic and clinical research describing the complex effects of excess thyroid hormone on carbohydrate metabolism.MethodsWe performed a MEDLINE search of the English-language literature using a combination of words (ie, “thyrotoxicosis and diabetes,” “diabetic ketoacidosis and thyroid storm,” “carbohydrate metabolism and hyperthyroid,” “glucose homeostasis and thyrotoxicosis”) to identify key articles addressing various aspects of the thyroid’s influence on carbohydrate metabolism.ResultsThyroid hormone affects glucose homeostasis via its actions on a variety of organs including increased hepatic glucose output, increased futile cycling of glucose degradation products between the skeletal muscle and the liver, decreased glycogen stores in the liver and skeletal muscle, altered oxidative and nonoxidative glucose metabolism, decreased active insulin output from the pancreas, and increased renal insulin clearance. Thyroid hormone also affects adipokines and adipose tissue, further predisposing the patient to ketosis.ConclusionsThyrotoxicosis can alter carbohydrate metabolism in a type 2 diabetic patient to such an extent that diabetic ketoacidosis develops if untreated. Based on the current understanding of this relationship, all diabetic patients should be screened for thyroid dysfunction because correcting hyperthyroidism can profoundly affect glucose homeostasis. Similarly, patients presenting in diabetic ketoacidosis should undergo a thyroid function assessment. (Endocr Pract. 2009;15:254-262)     

Significant Hypercortisolism During Fractionated Radiotherapy in a Patient with a Large Corticotroph Adenoma: A Case Report and Literature Review

ObjectiveWe describe a patient with a large, invasive corticotroph adenoma who developed severe hypercortisolism shortly after starting fractionated radiotherapy.MethodsWe reviewed the patient’s clinical course, along with relevant literature for similar reported cases.ResultsA 29-year-old man was referred for radiotherapy for a residual and recurrent, invasive corticotroph adenoma. Prior to radiotherapy, he had a normal urine free cortisol (UFC) level of 44.7 μg/24 hours, with minimal symptoms. Within 2 weeks of radiotherapy, he developed hypertension, ankle edema, and hypokalemia (potassium level, 2.8 mEq/L), with a markedly elevated UFC level of 9,203 μg/24 hours. His UFC gradually decreased and normalized by the end of radiotherapy. One month later, the patient became adrenal insufficient, with a nondetectable 24-hour UFC. His adrenal function slowly recovered in 3 months. We are aware of only one previous case report of clinically significant hypercortisolism following radiotherapy in Cushing disease.ConclusionRadiotherapy may result in acute severe hypercortisolism in patients with a large corticotroph adenoma. This uncommon, but clinically significant, acute adverse effect of radiotherapy suggests that clinical observation and biochemical monitoring during or soon after radiotherapy may be indicated. (Endocr Pract. 2014;20:e166-e170)     

Postmortem Diagnosis of Diabetic Ketoacidosis Presenting as the "Dead-in-Bed Syndrome"

Objective:To report a case of a young male with type 1 diabetes mellitus found dead in his bed, initially assumed to have died from hypoglycemia (i.e., the “dead in bed” syndrome). However, his autopsy findings revealed that diabetic ketoacidosis (DKA) was the cause of death.MethodsWe present the laboratory and autopsy findings of the patient, highlighting the importance of laboratory analyses of the vitreous humor and microscopy of kidney tissue when investigating the cause of sudden death in patients with type 1 diabetes.ResultsA 25-year-old healthy male with type 1 diabetes on continuous subcutaneous insulin infusion therapy was found dead in his undisturbed bed. An autopsy included vitreous humor analyses. His results were as follows: glucose of 755 mg/dL (reference range 70-105 mg/dL), anion gap > 36 mEq (reference range 4-12 mEq/L), elevated acetone at 66 mg/dL (reference range negative), which were consistent with DKA. Renal microscopy demonstrated subnuclear vacuoles in the proximal tubules, 1 of 2 lesions were described as an Armanni-Ebstein lesion, which is a postmortem finding in patients who die from diabetic coma.ConclusionThe most likely cause of death at home in young patients with type 1 diabetes is severe hypoglycemia. However, an autopsy of the present case confirmed DKA based on vitreous humor biochemistry and microscopic examination of the kidneys, which demonstrated the Armanni-Ebstein phenomenon. Analysis of the vitreous fluid and microscopic examination of the kidneys for the presence of Armanni-Ebstein lesion can be used to help determine the cause of death in patients with type 1 diabetes mellitus. (Endocr Pract. 2014;20:e123-e125)     

Treatment of Diabetic Ketoacidosis and the Weekend Effect at an Urban Tertiary-Care Center

Objective: Weekend admission has been associated with higher morbidity and mortality, but the relationship between diabetic ketoacidosis (DKA) outcomes and this weekend effect is unclear. To better characterize it, we examined the outcomes of patients admitted with DKA to an urban tertiary-care center.Methods: This retrospective study included pediatric and adult patients admitted to Montefiore Health System from January 1, 2008, through December 31, 2018, with a primary or secondary diagnosis of DKA as identified by International Classification of Diseases (ICD)-9 and -10 codes; all ICD diagnoses were present on admission. Only the first admission for each patient was analyzed, and patients were excluded if their initial anion gap was less than 13 mEq/L. A subcohort comprised of patients with documented biochemical evidence of DKA resolution was also analyzed. The Friday-Saturday weekend was defined as the period between midnight on Friday and midnight on Sunday; the Saturday-Sunday weekend was similarly defined. The following outcomes were compared between weekday and weekend groups: length of stay; time to initiation of subcutaneous insulin; and time to each of the following: venous pH >7.3, blood glucose <200 mg/dL, and anion gap ≤12 mEq/L. Odds of 30-day all-cause mortality and 30-day all-cause and DKA-specific readmission were also examined.Results: Over 11 years, 4,703 patients were included in the overall cohort, and 648 were included in the subcohort. For both weekend definitions, weekend admission did not produce differences in any outcome for either study cohort.Conclusion: No weekend effect on DKA outcomes was detected at an urban tertiary-care center.Abbreviations: AG = anion gap; CCI = Charlson Comorbidity Index; DKA = diabetic ketoacidosis; ICD = International Classification of Diseases; IVI = intravenous insulin; LOS = length of stay; SCI = subcutaneous insulin     

Management of Hyperglycemia in Diabetic Patients with Hematologic Malignancies During Dexamethasone Therapy

ObjectiveTo compare the response to different insulin regimens for management of hyperglycemia in diabetic patients with hematologic malignancies who are receiving dexamethasone.MethodsA retrospective analysis was conducted to determine whether a basal bolus insulin (BBI) regimen with detemir and aspart is superior to a sliding scale regular insulin (SSI) regimen for management of hyperglycemia in hospitalized diabetic patients receiving dexamethasone.ResultsForty patients with hematologic malignancies were treated with intravenous (8 to 12 mg/day) or oral (40 mg/day) dexamethasone for 3 days. The average blood glucose (BG) level was 301 ± 57 mg/dL in the SSI group (n = 28) and 219 ± 51 mg/dL in the BBI group (n = 12) (P <.001). The BBI regimen resulted in an average BG reduction of 52 ± 82 mg/dL throughout the course of dexa-methasone therapy, while the SSI regimen produced an increase in the mean daily BG level of 128 ± 77 mg/dL (P <.001). On the last day of dexamethasone administration, the insulin requirement was 49 ± 29 units/day in the SSI group and 122 ± 39 units/day in the BBI group (P <.001). Three patients in the SSI group developed diabetic ketoacidosis or hyperosmolar hyperglycemia during steroid therapy. No hypoglycemia was observed in either group. The length of stay and infection rates were similar between groups.ConclusionBasal and bolus insulin regimen is an effective and safe approach for managing dexamethasone-induced hyperglycemia in hospitalized patients with hematologic malignancies. (Endocr Pract. 2013;19:231-235)     

Diabetes: A Cardiac Condition Manifesting as Hyperglycemia

ObjectiveTo investigate the reasons for the increased risk of cardiovascular events and mortality in individuals with type 2 diabetes mellitus.MethodsFrom January 1990 to March 2008, literature relevant to low-density lipoprotein (LDL) and highdensity lipoprotein (HDL) cholesterol, hemoglobin A1c, acute hyperglycemia, postprandial hyperglycemia, systolic blood pressure, insulin resistance, endothelial dysfunction, microalbuminuria, diabetic cardiomyopathy, left ventricular hypertrophy, function inhibitors of the renin-angiotensin system and sympathetic nervous system, statins, and antiplatelet therapy as related to cardiac events and mortality in type 2 diabetic patients was reviewed.ResultsIncreased numbers of cardiac events and mortality in type 2 diabetes are associated with low HDL and high LDL cholesterol, high hemoglobin A1c, and high systolic blood pressure. Acute hyperglycemia, postprandial hyperglycemia, and possibly use of traditional sulfonylureas also increase incidence of cardiac events and mortality. The presence of microalbuminuria signifies endothelial dysfunction and an increased risk of cardiac events. Hypertension should be treated to goals that are lower in the diabetic patient with multiple therapies, which include suppressors of the renin-angiotensin and sympathetic nervous systems. Decreased improvement in outcomes for the diabetic patient with cardiovascular disease may be accounted for by the failure to treat insulin resistance and ventricular dysfunction. The high incidence of heart failure in the diabetic patient is due to the toxic triad of diabetic cardiomyopathy, left ventricular hypertrophy, and extensive coronary artery disease.ConclusionHigh risk of cardiovascular events, heart failure, and mortality in type 2 diabetes can be lowered with risk factor reduction and therapies that prevent or improve ventricular function. (Endocr Pract. 2008;14:924-932)     

Preserved Proinsulin Production in Homozygous Protein Tyrosine Phosphatase Nonreceptor Type 22 C1858T Variant Type 1 Diabetes: A Possible Explanation for Absence of Overt Ketoacidosis Despite Omission of Exogenous Insulin

ObjectiveTo report a postulated mechanism for resistance to overt ketoacidosis due to prolonged insulin omission in a severely hyperglycemic woman with a 14-year history of autoimmune type 1 diabetes (T1D).MethodsHistory, physical examination, laboratory testing, and genotyping were performed. We also review the medical literature pertinent to this patient’s phenotype and genotype.ResultsProinsulin levels remained within the normal range (suppressed with hypoglycemia) despite simultaneous almost unmeasurable C-peptide levels during hyperglycemia. We confirmed a homozygous (TT) variant of protein tyrosine phosphatase nonreceptor type 22 (PTPN22) 1858T, a T1D susceptibility gene associated with higher proinsulin levels.ConclusionThe extraordinarily preserved proinsulin biological activity may explain the unusual resistance to overt ketoacidosis despite omission of exogenous insulin administration for extended periods of time. The role of the associated PTPN22 1858TT variant remains speculative. (Endocr Pract. 2013;19:426-430)     

Diabetic Ketoacidosis in Peruvian Patients with Type 2 Diabetes Mellitus

ObjectiveTo describe the clinical and laboratory characteristics of diabetic ketoacidosis (DKA) in adult Peruvian patients with type 2 diabetes mellitus.MethodsIn this cross-sectional analysis, we reviewed clinical charts of type 2 diabetic patients with DKA admitted to Cayetano Heredia Hospital between 2001 and 2005 for data on demographics, previous treatment, previous hospital admissions for DKA, family history of diabetes, precipitating factors, hospital course, mortality, and insulin use 3 and 6 months after the index DKA episode. Patients older than 18 years who had confirmed DKA were included. Patients with type 1 diabetes mellitus were excluded.ResultsWe report on 53 patients with DKA for whom complete clinical and laboratory data were available. Of the 53 patients, 39 (74%) were men; mean age (± SD) was 45 ± 12 years; and 22 (42%) had no previous diagnosis of type 2 diabetes. The following mean (± SD) laboratory values were obtained at DKA diagnosis: glucose, 457 ± 170 mg/dL; pH, 7.15 ± 0.14; bicarbonate, 7.73 ± 6 mEq/L; and anion gap, 24.45 ± 7.44 mEq/L. Of the 53 DKA episodes, 35 (66%) were severe (arterial pH < 7.0 and/or serum bicarbonate < 10 mEq/L). The following precipitating factors were discerned: discontinuation of treatment in 21 (40%), infections in 16 (30%), intercurrent illness in 3 (6%), and no identifiable cause in 13 (25%). Mortality rate was 0%. Three and 6 months after the index DKA episode, insulin was used by 65% and 56% of patients, respectively.ConclusionIn countries with a low incidence of type 1 diabetes, DKA is frequently reported in patients with type 2 diabetes. In this study, 42% of patients had new-onset disease. Most DKA episodes were severe and were related to infection or noncompliance with treatment. (Endocr Pract. 2008;14:442-446)     

Hypertension in a Patient with Aldosterone Deficiency

ObjectiveTo describe a patient with aldosterone synthase deficiency, who presented with failure to thrive, hypovolemic hyponatremia, and the unexpected finding of hypertension.MethodsWe present a case report, review the related literature, and outline a possible mechanism for the concomitant occurrence of high blood pressure and hyponatremia in this patient.ResultsA 5-month-old infant with unambiguous female genitalia was admitted to our hospital with failure to thrive and hyponatremia. Her blood pressure was 115/88 mm Hg (> 95% for age). The serum sodium concentration was 123 mEq/L (normal for age, > 130), and the potassium level was 5.3 mEq/L (normal, 3.5 to 5.3). A direct renin measurement by immunochemiluminescence assay was 11,400 μU/mL (normal, < 5), and the aldosterone level was 4 ng/dL (normal, 2 to 70). These findings indicated a diagnosis of aldosterone synthase deficiency. Treatment with fludrocortisone and sodium chloride was begun, but the hypertension worsened. Therapy with an angiotensin-converting enzyme inhibitor was transiently required.ConclusionAngiotensin II, a potent vasoconstrictor, is an intermediate in the renin-angiotensin system. We believe that this protein was the cause of the hypertension in the setting of aldosterone deficiency in our patient. (Endocr Pract. 2005;11:104-107)     

Ketosis-Prone Type 2 Diabetes: Effect of Hyperglycemia on β-Cell Function and Skeletal Muscle Insulin Signaling

ObjectiveTo determine the underlying mechanism for the severe and transient β-cell dysfunction and impaired insulin action in obese African American patients with ketosis-prone diabetes.MethodsThe effect of sustained hyperglycemia (glucotoxicity) and increased free fatty acids (lipotoxicity) on β-cell function was assessed by changes in insulin secretion during a 20-hour glucose (200 mg/m² per minute) and a 48-hour Intralipid (40 mL/h) infusion, respectively. Insulin-activated signaling pathways and pattern of Akt-1 and Akt-2 expression and insulin-stimulated phosphorylation were analyzed in skeletal muscle biopsy specimens. Studies were performed in an obese African American woman within 48 hours after resolution of diabetic ketoacidosis and 1 week after discontinuation of insulin treatment.ResultsDextrose infusion rapidly increased C-pep-tide levels from a baseline of 3.2 ng/mL to a mean of 7.1 ± 0.5 ng/mL during the first 8 hours of infusion; thereafter, C-peptide levels progressively declined. Lipid infusion was not associated with any deleterious effect on insulin and C-peptide secretion. Initial in vitro stimulation of muscle tissue with insulin resulted in a substantial and selectively decreased Akt-2 expression and insulin-stimulated phosphorylation on the serine residue. Improved metabolic control resulted in 70% greater Akt expression at near-normoglycemic remission in comparison with the period of hyperglycemia.ConclusionHyperglycemia, but not increased free fatty acid levels, led to progressive β-cell dysfunction and impaired insulin secretion. Hyperglycemia was also associated with diminished skeletal muscle Akt expression and phosphorylation in an African American woman with ketosis-prone diabetes, and this defect improved notably with aggressive insulin therapy. These results indicate the importance of glucose toxicity in the pathogenesis of keto-sis-prone diabetes in obese African American patients. (Endocr Pract. 2007;13:283-290)     

Unusual Cause of Ectopic Secretion of Adrenocorticotropic Hormone: Cushing Syndrome Attributable to Small Cell Prostate Cancer

ObjectiveTo report a rare cause of ectopic adrenocorticotropic hormone (ACTH) secretion leading to severe Cushing syndrome.MethodsWe describe the clinical presentation and management of a case of Cushing syndrome attributable to ectopic ACTH secretion from small cell cancer of the prostate.ResultsIn a 70-year-old man with hypertension and diabetes, congestive heart failure developed. He was found to have severe hypokalemia (serum potassium, 1.7 mEq/L) and a huge pelvic mass on a computed tomographic scan performed because of a complaint of urinary retention. Transurethral biopsy of the prostate showed features of small cell prostate cancer. Hormonal evaluation revealed a high urine free cortisol excretion of 6,214.5 μg/d (reference range, 36 to 137), confirming the diagnosis of Cushing syndrome. A serum ACTH level was elevated at 316 ng/dL (reference range, 10 to 52). An overnight highdose (8 mg orally) dexamethasone suppression test was positive (serum cortisol levels were 43.2 and 41 μg/dL before and after suppression, respectively), and magnetic resonance imaging of the pituitary gland disclosed no abnormalities. A prostate biopsy specimen showed small cell prostate cancer with positive staining for ACTH. The tumor was found to be unresectable, and the poor condition of the patient did not allow for bilateral adrenalectomy. He was treated with ketoconazole and metyrapone, which yielded good temporary control of his Cushing syndrome (24-hour urine free cortisol decreased to 55.2 μg/d). He received 1 cycle of chemotherapy (etoposide and cisplatin), but he died 6 months later as a result of sepsis.ConclusionSmall cell prostate cancer is a rare subtype that can be associated with ectopic secretion of ACTH and severe Cushing syndrome. With this subtype of prostate cancer, Cushing syndrome should be considered and appropriately managed. (Endocr Pract. 2010;16:249-254)     

Tolvaptan for the Management of Syndrome of Inappropriate Antidiuretic Hormone Secretion: Lessons Learned In Titration of Dose

ObjectiveTo report a patient with idiopathic syndrome of inappropriate antidiuretic hormone secretion (SIADH) who developed profound aquaresis with symptomatic extracellular fluid depletion after initiation of therapy with tolvaptan who was later successfully treated with smaller doses of compounded tolvaptan to prevent rapid correction of serum sodium.MethodsCase report and review of the literature.ResultsA 51-year-old woman was diagnosed with SIADH during admission for elective surgery resulting in multiple complications. The patient failed multiple therapies including fluid restriction, salt tablets, and demeclocycline. She was admitted to the hospital for initiation of tolvaptan therapy. After a 15-mg dose of tolvaptan, the patient had rapid increase in urine output and symptomatic hypotension. Sodium levels corrected rapidly overnight from 126 mEq/L to 139 mEq/L. A lower dose of tolvaptan resulted in similar symptoms and sodium correction. Due to continuing symptoms of hyponatremia including headaches, nausea, vomiting, and paresthesias after reinitiation of fluid restriction and salt tablets, tolvaptan was compounded to continue to titrate at lower doses. The patient was then admitted and tolvaptan was initiated at a dose of 1.5 mg with no significant improvement in sodium levels. Tolvaptan was titrated to 3 mg, which resulted in correction of sodium to 129 mEq/L with no associated symptoms of hypovolemia.ConclusionsTolvaptan should be initiated in an inpatient setting with close monitoring of serum sodium levels. In patients who are not able to tolerate recommended dosages, consideration should be given to using a compounded formulation to further titrate to lower doses.(Endocr Pract. 2011;17:e97-e100)     

Pasireotide and Mifepristone: New Options in the Medical Management of Cushing's Disease

ObjectiveTo review and evaluate medical therapies for Cushing’s disease (CD), with an emphasis on recent clinical trial experience with pasireotide and mifepristone, and to discuss the therapeutic potential and appropriate selection of these compounds in this patient population.MethodsRecently published Phase III trial data for each compound are reviewed and assessed, and relative benefits and risks are examined and compared where possible.ResultsMifepristone and pasireotide are both potentially beneficial for CD patients but have greatly dissimilar mechanisms of action and adverse event (AE) profiles. Pasireotide acts at the level of the pituitary adenoma, reducing cortisol levels through inhibition of adrenocorticotropic hormone (ACTH) release. However, pasireotide reduces insulin secretion and incretin hormone response and is associated with significant risk for new or worsening hyperglycemia. Mifepristone ameliorates the signs and symptoms of hypercortisolemia via glucocorticoid receptor (GR2) blockade, but this approach raises serum cortisol levels and increases risk for adrenal insufficiency (AI), hypokalemia, and endometrial thickening. While response to pasireotide can be monitored via measurements of serum, urine, or late-night salivary cortisol, evaluation of response to mifepristone is solely based on changes in clinical parameters (e.g., hyperglycemia, hypertension, body weight/composition).ConclusionManagement of persistent CD is challenging, and the decision to initiate medical treatment hinges on many factors. Pasireotide may be a more attractive option for most patients due to its action at the underlying tumor and the ability to monitor biochemical responses. However, mifepristone may be more appropriate when it is necessary to avoid or minimize risk for hyperglycemiarelated complications. (Endocr Pract. 2014;20:84-93)