Atrial Fibrillation is Associated with Impaired Atrial Mitochondrial Energetics and Supercomplex Formation in Adults with Type 2 Diabetes

Publication date: Available online 31 May 2018Source: Canadian Journal of DiabetesAuthor(s): Georges N. Kanaan, David Patten, Calum Redpath, Mary-Ellen HarperAbstractBackgroundType 2 diabetes mellitus (T2DM) is a chronic progressive disease associated with increased risk for cardiovascular diseases (CVDs) and with impaired mitochondrial metabolism in cardiac and skeletal muscles. Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is associated with significant morbidity and mortality. T2DM is also one of the prevalent concomitant diseases in patients with AF. During AF, myocardial energy demand is high due to electrical activity. To-date however, very little is known about the effects of AF on atrial muscle mitochondrial energetics.HypothesisWe hypothesized that pre-existing fibrillation or T2DM impacts atrial mitochondrial energetics and electron transport chain (ETC) supercomplexes.MethodsAtrial appendages were collected from consented patients with and without pre-existent AF undergoing coronary artery bypass graft (CABG) surgery. Mitochondrial functional analyses were conducted in permeabilized myofibers using high resolution respirometry.Results and conclusionResults show impaired complex I and II function in addition to impaired ETC supercomplex assembly in patients with diabetes and AF compared to patients with diabetes but without AF. There were no differences in mitochondrial content in atrial muscle between groups. There was a strong trend ...
Source: Canadian Journal of Diabetes - Category: Endocrinology Source Type: research