Common tests for pancreatic islet function include insulin, C-peptide, and blood glucose testing. To detect insulin and C-peptide, insulin and C-peptide values can be measured in the morning on an empty stomach, followed by drinking glucose water and measuring the values after 0.5 hours, 1 hour, 2 hours, and 3 hours, respectively. Plasma insulin reflects the function of pancreatic β-cells; blood C-peptide concentration is not interfered by exogenous insulin and anti-insulin antibodies, and can more accurately reflect the function of pancreatic β-cells. Blood glucose testing can assist in assessing islet function, including fasting blood glucose, glucose tolerance test, and glycosylated hemoglobin. Specific islet function testing methods can be chosen according to your own situation by consulting your doctor.