GLP1R and diabetes mellitus: The National Heart, Lung and Blood Institute Heart Failure Clinical Research Network designed the Functional Impact of GLP-1 for Heart Failure Treatment (FIGHT) study (NCT01800968) to test the hypothesis that liraglutide would improve myocardium bioenergetics leading to post-hospitalization clinical stability in subjects with advanced HF and reduced left ventricular ejection fraction, with and without diabetes [47].