Figure 1.

IR and T2DM. Insulin secretion by the pancreas is influenced by the interplay of various hormones (hormone, IGF-1, glucagon, glucocorticoids, and catecholamines) in order to regulate glucose levels in the bloodstream. However, insulin failure to manage blood glucose will lead to the progression of IR. IR will compromise endothelial function, rendering liver, skeletal muscle, and fat cells unable to use glucose. This worsens hyperinsulinemia, and the pancreas is already incapable of keeping normal blood glucose despite secreting large amounts of insulin. Blood plasma glucose levels keep increasing and the feedback loop enhances IR further. At this stage, the patient is diagnosed with T2DM. Abbreviations: ED, endothelial dysfunction; FFA, free fatty acid; IGF-1, insulin-like growth factor 1; IR, insulin resistance; T2DM, type 2 diabetes mellitus.