An Iron-chelating Agent Improved the Cardiac Function in a Patient with Severe Heart Failure Due to Hereditary Hemochromatosis.

A 24-year-old man was admitted to our hospital because of severe heart failure. Although he was treated with diuretics and positive inotropic agents, his heart failure progressed. An endomyocardial biopsy revealed iron deposition in his myocytes. Finally, he was diagnosed with hereditary hemochromatosis. After starting administration of an iron-chelating agent in addition to conventional treatment for heart failure, his condition improved. We should consider hemochromatosis in heart failure patients with severe right ventricular dysfunction in addition to left ventricular dysfunction.

Impact of glucagon response on early postprandial glucose excursions irrespective of residual ß-cell function in type 1 diabetes: A cross-sectional study using a mixed meal tolerance test.

AIMS/INTRODUCTION: Controlling postprandial glucose levels in patients with type 1 diabetes is challenging even under the adequate treatment of insulin injection. Recent studies showed that dysregulated glucagon secretion exacerbates hyperglycemia in type 2 diabetes patients, but little is known in type 1 diabetes patients. We investigated whether the glucagon response to a meal ingestion could influence the postprandial glucose excursion in patients with type 1 diabetes. MATERIALS AND METHODS: We enrolled 34 patients with type 1 diabetes and 23 patients with type 2 diabetes as controls. All patients underwent a liquid mixed meal tolerance test. We measured levels of plasma glucose, C-peptide and glucagon at fasting (0 min), and 30, 60 and 120 min after meal ingestion. All type 1 diabetes patients received their usual basal insulin and two-thirds of the necessary dose of the premeal bolus insulin. RESULTS: The levels of plasma glucagon were elevated and peaked 30 min after the mixed meal ingestion in both type 1 diabetes and type 2 diabetes patients. The glucagon increments from fasting to each time point (30, 60 and 120 min) in type 1 diabetes patients were comparable to those in type 2 diabetes patients. Among the type 1 diabetes patients, the glucagon response showed no differences between the subgroups based on diabetes duration (<5 vs ≥5 years) and fasting C-peptide levels (<0.10 vs ≥0.10 nmol/L). The changes in plasma glucose from fasting to 30 min were positively correlated with those in glucagon, but not C-peptide, irrespective of diabetes duration and fasting C-peptide levels in patients with type 1 diabetes. CONCLUSIONS: The dysregulated glucagon likely contributes to postprandial hyperglycemia independent of the residual ß-cell functions during the progression of type 1 diabetes.

RENAL FUNCTION AND PLASMA RENIN ACTIVITY AS POTENTIAL FACTORS CAUSING HYPERKALEMIA IN PATIENTS WITH THYROID CARCINOMA UNDERGOING THYROID HORMONE WITHDRAWAL FOR RADIOACTIVE IODINE THERAPY.

Objective: Hypothyroidism is not commonly considered a cause of hyperkalemia. We previously reported that hyperkalemia was observed mainly in elderly patients treated with renin-angiotensin-aldosterone system (RAS) inhibitors when levothyroxine treatment was withdrawn for the thyroidectomized patients with thyroid carcinoma to undergo radioactive iodine treatment. Here, we investigated whether acute hypothyroidism causes hyperkalemia in patients who were not treated with RAS inhibitors. We also investigated factors influencing potassium metabolism in hypothyroid patients. Methods: We conducted a single-center, prospective cohort study of 46 Japanese patients with thyroid carcinoma undergoing levothyroxine withdrawal prior to radioiodine therapy. All patients were normokalemic before levothyroxine withdrawal. Blood samples were analyzed 3 times: before, and at 3 and 4 weeks after levothyroxine withdrawal. We investigated factors that may be associated with the elevation of serum potassium levels from a euthyroid state to a hypothyroid state. Results: None of the patients developed symptomatic hyperkalemia. The mean serum potassium level was significantly higher at 4 weeks after levothyroxine withdrawal compared to baseline. The serum sodium levels, the estimated glomerular filtration rate (eGFR), and the plasma renin activity (PRA) decreased significantly as hypothyroidism advanced. In contrast, the plasma levels of adrenocorticotropic hormone, cortisol, aldosterone, and antidiuretic hormone were not changed, while serum thyroid hormone decreased. At 4 weeks after their levothyroxine withdrawal, the patients' serum potassium values were significantly correlated with the eGFR and the PRA. Conclusion: Acute hypothyroidism can cause a significant increase in the serum potassium level, which may be associated with a decreased eGFR and decreased circulating RAS. Abbreviations: ACTH = adrenocorticotropic hormone; ADH = antidiuretic hormone; ATPase = adenosine triphosphatase; eGFR = estimated glomerular filtration rate; HbA1c = glycated hemoglobin; K+ = potassium; Na+ = sodium; PRA = plasma renin activity; RAS = renin-angiotensin-aldosterone system; T4 = thyroxine; TSH = thyroid-stimulating hormone.

Sex differences in insulin and glucagon responses for glucose homeostasis in young healthy Japanese adults.

It has been reported that glucose responses during the oral glucose tolerance test differ between healthy women and men. However, it remains unknown what factors contribute to these differences between the sexes. The present study analyzed the insulin and glucagon responses during the oral glucose tolerance test in 25 female and 38 male healthy young adults aged 22-30 years. The plasma glucose levels at 120 min were significantly higher in women than men. Insulin secretion was significantly greater at 30, 90 and 120 min from baseline in women than men. Glucagon suppression was greater at 30 and 120 min from baseline in men than women when determined by a sandwich enzyme-linked immunosorbent assay glucagon kit. These results suggest that the differences in glucose responses during the oral glucose tolerance test are mediated by the difference between the sexes in bi-hormonal responses in healthy individuals.

Thyroid storm precipitated by duodenal ulcer perforation.

Thyroid storm is a rare and life-threatening complication of thyrotoxicosis that requires prompt treatment. Thyroid storm is also known to be associated with precipitating events. The simultaneous treatment of thyroid storm and its precipitant, when they are recognized, in a patient is recommended; otherwise such disorders, including thyroid storm, can exacerbate each other. Here we report the case of a thyroid storm patient (a 55-year-old Japanese male) complicated with a perforated duodenal ulcer. The patient was successfully treated with intensive treatment for thyroid storm and a prompt operation. Although it is believed that peptic ulcer rarely coexists with hyperthyroidism, among patients with thyroid storm, perforation of a peptic ulcer has been reported as one of the causes of fatal outcome. We determined that surgical intervention was required in this patient, reported despite ongoing severe thyrotoxicosis, and reported herein a successful outcome.