Before you become frankly diabetic there’s a marker in your blood that starts to rise, called c-peptide. I measure c-peptide in my patients to determine their risk for insulin resistance.
C-peptide is a protein molecule that is produced by the pancreas and binds insulin to pro-insulin. While the pancreas produces enzymes to help you digest your food, it is also an endocrine gland that produces hormones, insulin and glucagon , that are transported by the blood to all the cells of your body. Insulin gets sugar into the cells. Glucagon gets sugar out.
Once released in the bloodstream, the triple complex of insulin~c-peptide~pro-insulin splits. The pancreas reuptakes pro-insulin to make more insulin. Insulin binds with blood glucose to escort it into the cells for energy production. C-peptide floats freely in the blood.
C-peptide reflects how much insulin your pancreas is producing. Type 1 Diabetics produce no insulin so their c-peptide is not measurable. As you become more insulin resistant, your pancreas produces more insulin. C-peptide levels rise. The higher your c-peptide, the more insulin you are producing. Over years of producing too much insulin, the pancreas becomes exhausted and eventually patients with Type 2 Diabetes may need to take insulin.