GCG and diabetes mellitus: The main limitation of our study is the use of intravenous glucose loading instead of oral glucose loading as performed in clinical DNP studies.10, 11 Intravenous glucose loading increases blood glucose levels faster and bypasses the incretin response from the GI tract, which modulates insulin secretion.41, 42 In patients with diabetes, the incretin response from the GI tract is lower,43 which could potentially lead to different effects on hyperpolarized [1‐13C] pyruvate metabolism in the heart.