Several questions about pancreatic islet function test

It is often seen that many people who are newly diagnosed with diabetes or have been ill for a certain period of time have many misunderstandings about the function of pancreatic islets. High glucose toxicity will affect the function of pancreatic islet cells. At what level of blood glucose can the islet cell function test be performed? 1 The patient had high blood glucose at the time of onset, with fasting 17.8mmol/L and HbA1c 14.3%. He was in a state of hyperglycemia, which is also called hyperglycemia. Although high glucose toxicity will inhibit pancreatic islet function, it is impossible to suppress C-peptide to the level of absolute deficiency, that is, fasting C-peptide <0.2nmol/L (equivalent to 0.6mg/ml).

 

At present, no textbook clearly mentions the level of blood sugar at which pancreatic islet cell function can be tested. Professor Weng's research shows that after two weeks of intensive insulin treatment for newly diagnosed hyperglycemia patients (including 1 week when blood sugar reaches the target and 1 week when blood sugar stabilizes at a better level), the endogenous pancreatic islet function is stopped and the endogenous pancreatic islet function is detected, and the reversible part of the pancreatic islet cells is found. Function can be restored. In clinical practice, insulin is generally used to control blood sugar for one month and then the islet cell function test is performed to preliminarily rule out the impact of high glucose toxicity on islet cell function. Is it necessary to stop insulin and secretagogues when performing islet cell function tests, and for how long? 2 Whether insulin or secretagogues need to be stopped when performing islet function tests depends on the level of blood sugar control.

 

If fasting blood sugar is below 5mmol/L, the stimulation threshold for endogenous insulin is too low, and the drug generally needs to be discontinued. If the fasting blood sugar is 8 or 9mmol/L, there is no need to stop basal insulin. In order to avoid postprandial blood sugar being too low to stimulate endogenous insulin, you can stop taking insulin during a meal, that is, within half a day of making steamed buns. It can prevent the patient's blood sugar from rising too high. Secretagogues are discontinued in the same manner as insulin. At what level of insulin or C-peptide can be called "hyperinsulinemia" in the islet function test? 3 There is currently no cut-off point for determining hyperinsulinemia. Hyperinsulinemia is divided into two conditions: absolute high and relatively high. : Absolutely high means that the insulin level is higher than the upper limit of normal. When this occurs and blood sugar cannot be controlled at a reasonable level, insulin resistance may exist.

 

For example, normal people's fasting insulin level is 3-23µU/L, and the median insulin level of most people is 10-15µU/L. If the measured fasting insulin exceeds 23µU/L, it is an absolute increase. After 1 hour of glucose loading, the average insulin value is around 60µU/L. If it is more than 2 standard deviations, it is also considered high. Relatively high means that the insulin level is above the median normal value and close to the upper limit, but the blood sugar is high. For example, the fasting insulin level is 20µU/L, which does not exceed the upper limit, but the fasting blood sugar is 10mmol/L. This also indicates the existence of insulin resistance. Is it easier for new-onset diabetic patients to reach the honeymoon stage when taking GLP-1 receptor agonists or DPP-4 inhibitors? 4 Theoretically, it is easier for new-onset diabetic patients to take GLP-1 receptor agonists or DPP-4 inhibitors Reaching the honeymoon stage, it is currently only seen in basic research that this type of drug can reduce islet cell apoptosis and increase the number of beta cells. What is the difference in pathogenesis between diabetic patients with obvious metabolic syndrome and elderly patients with new-onset diabetes without obvious metabolic syndrome? 5 Insulin resistance does not increase with age, but pancreatic beta cell function decreases with age. , so age is an important risk factor for the onset of T2DM. The onset of young T2DM patients is mostly caused by insulin resistance induced by environmental factors, often accompanied by metabolic syndrome. New-onset T2DM in elderly patients is mostly caused by reduced endogenous pancreatic islet function.