Pancreatic islet function is mainly determined by drawing blood for laboratory tests, the more standard islet function measurement is called insulin release test. The main procedure is for the patient to go to the hospital, have blood drawn to measure insulin levels in the fasting state, and then drink 75g of glucose. One hour and two hours after drinking the glucose, blood is drawn to measure insulin levels, and the results provide an overall assessment of the patient’s insulin function. Some patients are already taking oral sulfonylurea hypoglycemic drugs, which may affect the measurement of insulin. At this time, C-peptide can be measured, C-peptide is not affected by endogenous insulin secretion, and to a certain extent, it can reflect the patient’s pancreatic islet function, C-peptide measurement method is the same as insulin measurement.