Insulin is secreted by pancreatic beta cells and is a protein hormone. Normal adult fasting basal plasma insulin concentration is 35-145pmol/L, which can rise to 5-10 times of the basal value about one hour after eating. Insulin is a key hormone to promote the anabolism of substances and maintain the stability of blood glucose concentration, participate in the storage of energy substances in the body and promote growth and development, mainly in the following aspects: 1. promote glycogen synthesis, inhibit glycogenolysis, inhibit gluconeogenesis Insulin can promote the synthesis of protein and inhibit the breakdown of protein. 4. If insulin is not secreted enough, it will cause diabetes and finally cause lesions in the eyes, kidneys, heart, nerves, blood vessels and other organs and finally lead to a decline in the function of these organs, which can be life-threatening.