Myocardial Infarction and Cardiac Arrest in a Patient With Severe Undiagnosed Hypothyroidism During Bronchoscopy.

Thyroid hormones have an integral role in cardiac homeostasis, and hypothyroidism may be associated with impaired myocardial contractility, altered endothelial function, and blunted response to catecholamines. Herein, the case of a patient with undiagnosed severe hypothyroidism, who developed an acute myocardial infarction and cardiac arrest during sedation for bronchoscopy, is described. He required prolonged resuscitation, which included coronary catheterization and placement of an intra-aortic balloon pump. The resuscitation was noteworthy for blunted physiologic responses to large doses of epinephrine; in particular, persistent bradycardia without evidence of conduction abnormalities. On admission to the intensive care unit, he was hypothermic (31.4°C), bradycardic, and hypotensive. Laboratory investigations revealed profound hypothyroidism, and thyroid hormone replacement was initiated. Within hours of initiation of thyroid hormone replacement, the need for vasopressor support was reduced. He had a complete recovery and was discharged home neurologically intact. The authors of the present report believe that this favorable neurologic outcome could be attributed to efficient resuscitation, prompt coronary revascularization, and profound hypothermia likely related to a hypothyroidism-associated hypometabolic state.

Beneficial effect of recombinant rC1rC2 collagenases on human islet function: Efficacy of low-dose enzymes on pancreas digestion and yield.

A high number of human islets can be isolated by using modern purified tissue dissociation enzymes; however, this requires the use of >20 Wunsch units (WU)/g of pancreas for digestion. Attempts to reduce this dose have resulted in pancreas underdigestion and poor islet recovery but improved islet function. In this study, we achieved a high number of functional islets using a low dose of recombinant collagenase enzyme mixture (RCEM-1200 WU rC2 and 10 million collagen-degrading activity [CDA] U of rC1 containing about 209 mg of collagenase to digest a 100-g pancreas). The collagenase dose used in these isolations is about 42% of the natural collagenase enzyme mixture (NCEM) dose commonly used to digest a 100-g pancreas. Low-dose RCEM was efficient in digesting entire pancreases to obtain higher yield (5535 ± 830 and 2582 ± 925 islet equivalent/g, P < .05) and less undigested tissue (16.7 ± 5% and 37.8 ± 3%, P < .05) compared with low-dose NCEM (12WU/g). Additionally, low-dose RCEM islets retained better morphology (confirmed with scanning electron microscopy) and higher in vitro basal insulin release (2391 ± 1342 and 1778 ± 978 µU/mL; P < .05) compared with standard-dose NCEM. Nude mouse bioassay demonstrated better islet function for low-dose RCEM (area under the curve [AUC] 24 968) compared with low-dose (AUC-38 225) or standard-dose NCEM (AUC-38 685), P < .05. This is the first report indicating that islet function can be improved by using low-dose rC1rC2 (RCEM).

Pig islet xenotransplantation.

PURPOSE OF REVIEW: The current article reviews the rationale, sources and preparation of pig islets for xenotransplantation, and presents current progress in solving the problems associated with establishing pig islet transplant as a clinical treatment for type 1 diabetes. SUMMARY: Islet transplantation is an effective treatment option for type 1 diabetes, but the available supply of human pancreases is insufficient to meet the need and demand for obtaining islets. Pig islets provide a readily available source for islet transplantation, with trials in non-human primates demonstrating their potential to reverse diabetes. The risk of zoonosis can be reduced by designated pathogen-free breeding of the donor pigs, but porcine endogenous retroviruses (PERVs) that are integrated into the genome of all pigs are especially difficult to eliminate. However, clinical trials have demonstrated an absence of PERV transmission with a significant reduction in the number of severe hypoglycemic episodes and up to 30% reduction in exogenous insulin doses. A number of methods such as production of various transgenic pigs to better xenotransplantation efficiency and the encapsulation of islets to isolate them from the host immune system are currently being tested to overcome the xenograft immune rejection. Furthermore, ongoing research is also shedding light on factors such as the age and breed of the donor pig to determine the optimal islet quantity and function.

Marked Hypoleptinemia Precedes Overt Fat Loss in Immune Checkpoint Inhibitor-induced Acquired Generalized Lipodystrophy.

Immune checkpoint inhibitors (ICIs) targeting cancer cells that evade immune T-cell regulation have revolutionized the treatment of metastatic carcinomas. Unfortunately, secondary endocrinopathies associated with ICI, including adrenal insufficiency, primary hypothyroidism, autoimmune diabetes, and rarely hypoparathyroidism, are increasing. Lipodystrophy, presumably due to the autoimmune destruction of adipocytes, leading to metabolic complications, is a less recognized adverse effect of ICI therapy. We present a case of a 66-year-old Caucasian woman treated with pembrolizumab, an anti-programmed death 1 inhibitor, for metastatic lung adenocarcinoma. Fifteen months after the treatment initiation, she was found to have hyperglycemia, hyperlipidemia, and hepatic steatosis but without any evidence of autoimmune diabetes. She was also noted to have isolated buccal fat pad loss, raising suspicion of acquired lipodystrophy. Despite well-preserved subcutaneous fat over the trunk and limbs, she had undetectable serum leptin levels. Whole-body fluorodeoxyglucose (FDG)-positron emission tomography scan showed diffuse mild FDG activity throughout the subcutaneous tissue, suggesting underlying inflammation. Over the next 3 months, she developed progressive fat loss leading to generalized lipodystrophy. Adipose tissue dysfunction, secondary to ICI-induced subclinical panniculitis, precedes overt fat loss and is characterized by hypoleptinemia and metabolic abnormalities.

Canagliflozin-associated severe hyponatremia: a rare and potentially adverse effect?

Summary: Sodium-glucose cotransporter-2 inhibitors (SGLT2i) induce osmotic diuresis by inhibiting the proximal renal tubular reabsorption of the filtered glucose load, which in turn can occasionally lead to severe dehydration and hypotension amidst other adverse effects. We present a case of a 49-year-old man with type 2 diabetes mellitus (T2D) on canagliflozin, a SGLT2i. The patient was brought to the emergency room following a motor vehicle accident. He was confused and had an altered mental status. His blood alcohol and urine toxicology screens were negative. Initial investigations revealed that he had severe hyponatremia with euglycemic ketoacidosis. The adverse condition was reversed with close monitoring and timely management, and the patient was eventually discharged. This is the first report to suggest hyponatremia as a potentially serious adverse effect following SGLT2i therapy. Its impact on the renal tubule handling of sodium and water is not yet well characterized. While further studies are warranted to understand better the pathophysiological mechanisms associated with SGLT2i-induced adverse effects, timely dose reduction or perhaps even its temporary discontinuation may be recommended to prevent complications. Learning points: Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are usually well-tolerated, but some serious adverse effects have been documented. Our case report suggests hyponatremia as a potential, rare side effect of SGLT2i and makes physicians aware of the occurrence of such life-threatening but preventable complications. Timely and close monitoring of the patient, with temporary discontinuation of this drug, may be recommended towards effective management. Studies demonstrating a comprehensive understanding of SGLT2i-related electrolyte derangements are warranted.

Diabetic Ketoacidosis in Pregnancy: Clinical Risk Factors, Presentation, and Outcomes.

CONTEXT: Diabetic ketoacidosis (DKA) in pregnancy is an obstetric emergency with risk of maternofetal death. OBJECTIVE: This work aimed to evaluate DKA events in pregnant women admitted to our inpatient obstetric service, and to examine associated clinical risk factors, presentation, and pregnancy outcomes. METHODS: A retrospective cohort study was conducted at the Mayo Clinic, Rochester, Minnesota, USA, and included women aged 17 to 45 years who were treated for DKA during pregnancy between January 1, 2004 and December 31, 2021. Main outcome measures included maternal and fetal death along with a broad spectrum of maternal and fetal pregnancy outcomes. RESULTS: A total of 71 DKA events were identified in 58 pregnancies among 51 women, 48 (82.8%) of whom had type 1 diabetes. There were no maternal deaths, but fetal demise occurred in 10 (17.2%) pregnancies (6 miscarriages and 4 stillbirths). Maternal social stressors were frequently present (n = 30, 51.0%), and glycemic control was suboptimal (median first trimester glycated hemoglobin A1c = 9.0%). Preeclampsia was diagnosed in 17 (29.3%) pregnancies. Infants born to women with DKA were large for gestational age (n = 16, 33.3%), suffered from neonatal hypoglycemia (n = 29, 60.4%) and required intensive care unit admission (n = 25, 52.1%). CONCLUSION: DKA is associated with a high rate of maternofetal morbidity and fetal loss. Prenatal education strategies for women with diabetes mellitus should include a strong focus on DKA prevention, and clinicians and patients should have a high index of suspicion for DKA in all pregnant women who present with symptoms that could be attributed to this condition.

Intra-islet endothelial cell and ß-cell crosstalk: Implication for islet cell transplantation.

The intra-islet microvasculature is a critical interface between the blood and islet endocrine cells governing a number of cellular and pathophysiological processes associated with the pancreatic tissue. A growing body of evidence indicates a strong functional and physical interdependency of ß-cells with endothelial cells (ECs), the building blocks of islet microvasculature. Intra-islet ECs, actively regulate vascular permeability and appear to play a role in fine-tuning blood glucose sensing and regulation. These cells also tend to behave as "guardians", controlling the expression and movement of a number of important immune mediators, thereby strongly contributing to the physiology of islets. This review will focus on the molecular signalling and crosstalk between the intra-islet ECs and ß-cells and how their relationship can be a potential target for intervention strategies in islet pathology and islet transplantation.