Background: Our goal was to determine in healthy individuals and individuals with type 2 diabetes the impact of repeated episodes of hypoglycemia on the corrected QT (QTc) interval and the time course for QTc recovery. Further, since hypoglycemia increases aldosterone and patients with primary aldosteronism have prolonged QTc, we also determined whether mineralocorticoid receptor blockade prevents hypoglycemia-induced QTc alterations.
Methods: Twenty-seven healthy participants completed a double-blinded crossover trial contrasting 3 experimental conditions: 1) euglycemia, 2) hypoglycemia, and 3) hypoglycemia with mineralocorticoid receptor blockade pretreatment.
Purpose: Hypoglycemia is associated with increased mortality, though the mechanisms underlying this association are not established. Hypoglycemia impairs the counterregulatory hormonal and autonomic responses to subsequent hypoglycemia. It is unknown whether hypoglycemia elicits a generalized impairment in autonomic control of cardiovascular function in individuals with type 2 diabetes.
View Article and Find Full Text PDFContext: Hypoglycemia attenuates cardiovascular homeostatic autonomic control. This attenuation, known as the cardiovascular component of hypoglycemia-associated autonomic failure (HAAF), is characterized most notably by decreased baroreflex sensitivity (BRS) that begins during hypoglycemia and persists until at least the next day, despite return to euglycemia. Understanding the mechanisms underlying this reduction in BRS is important because BRS attenuation is associated with increased morbidity and mortality.
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