H3K27me3 MRI (magnetic resonance imaging) Medicine TGR5 atherosclerosis bariatric surgery blood pressure body mass index cardiac dysfunction cardiac remodeling cardiotonic steroids cardiovascular disease cardiovascular risks conduit artery deficiency dietary factor dietary salt intake echocardiogram epigenetics folate glucose regulation hepatocyte high-fat high-sugar diet homocysteine homocysteine and vascular disease hypocaloric isocaloric laparoscopic sleeve gastrectomy left ventricular mass liver