Recently, we often get questions from diabetic patients: When we visit the clinic, the endocrinologist always asks us to monitor not only fasting blood glucose but also 2-hour postprandial blood glucose, and our postprandial blood glucose is always high. What is the significance of postprandial glucose and why does it remain high? To answer this question, we have to start from the generation of high postprandial blood glucose.
In normal people, blood glucose starts to rise about 10 minutes after meal, and reaches a peak 1 hour after meal, but generally does not exceed 140mg/dl, and returns to the pre-meal level in 2-3 hours. Therefore, under normal circumstances, the average blood glucose level throughout the day does not exceed 100mg/d. This fine regulation of blood glucose is mainly regulated through the secretory response of insulin and glucagon.
Insulin secretion is pulsatile, and insulin secretion increases rapidly after meals to maintain the postprandial blood glucose level within a tighter range, and the plasma insulin level rapidly returns to the basal state between meals. There are two phases of postprandial insulin secretion, the first phase (early phase) of insulin secretion refers to the rapid rise of plasma insulin after rapid sedation of glucose, which peaks within a few minutes, followed by a rapid (within 10 minutes) decline, and the second phase refers to the insulin secretion that occurs after the first phase, which can last for several hours.
Early postprandial phase insulin secretion is physiologically important as it inhibits glucose production, attenuates the postprandial rise in blood glucose, reduces late hyperinsulinemia, and is important for maintaining 24-hour glycemic control.
Patients with type 2 diabetes and IGT mainly show abnormal insulin secretion pattern, i.e., reduced or absent in the first time phase, compensatory prolongation and slow increase in the second time phase, and failure to return to basal status between meals. Due to reduced insulin release in the early phase, delayed peak insulin secretion, weakened inhibition of postprandial glucagon secretion, increased hepatic glycogenolysis and hepatic and renal gluconeogenesis, resulting in a sustained increase in postprandial glucose (>140mg/dl), which peaks 2 hours after meals, and because of insulin resistance, the patient’s glucose clearance rate is significantly reduced, which exacerbates the postprandial glucose increase.
Post-prandial hyperglycemia in diabetes is very harmful to diabetic patients
Firstly, postprandial hyperglycemia in diabetes is the highest blood glucose level in a day, and its summation duration can be up to 8-10 hours or even longer. Long time high level blood glucose can cause insulin resistance and decrease of insulin secretion, aggravate diabetes itself and make blood glucose rise further, forming a vicious circle.
Secondly, a long period of high level of blood sugar can endanger a variety of important organs of the human body, including the heart, brain, blood vessels, eyes, nerves, kidneys, etc., these important organs are damaged that is the complications of diabetes, is dangerous to the health of diabetic patients, threatening the lives of patients, and in a variety of causes of diabetes complications, the most important factor for the post-prandial hyperglycemia, because the higher the blood sugar, the greater the amount of various cells into The higher the blood glucose, the greater the amount of damage caused to various cells, and this damage can be maintained for a long time and does not subside immediately after severe hyperglycemia.
Studies have shown that diabetic patients who only control fasting blood sugar and poorly control postprandial hyperglycemia have an increased incidence of myocardial infarction and mortality.
Postprandial blood glucose has such an important impact on diabetes, so it is clear how important it is to reduce postprandial blood glucose, but many diabetic patients often find their fasting blood glucose is normal, but postprandial blood glucose is often very high, even with oral hypoglycemic drugs or insulin treatment is not good control, what is the reason?
First of all, postprandial hyperglycemia is related to diabetes itself, as mentioned above, due to impaired insulin secretion in early phase and delayed insulin peak in diabetic patients, postprandial hyperglycemia is often significantly elevated, and if the patient is combined with severe insulin resistance, postprandial hyperglycemia will last for a long time.
Secondly, the high postprandial blood sugar is also related to the patient’s neglect of postprandial blood sugar. Most diabetic patients often only pay attention to fasting blood sugar when monitoring blood sugar, but rarely monitor postprandial blood sugar. As a result, once the doctor asks to check the postprandial blood sugar, they often find that their blood sugar is alarmingly high and the glycated hemoglobin is also obviously elevated.
Furthermore, postprandial hyperglycemia is also related to the patient’s diet. This is not only related to the secretion of more insulin-fighting hormones in the morning and the production of large amount of glucose by the liver, but also may be related to the quality, quantity and cooking method of the patient’s breakfast. Some patients like to eat thin rice for breakfast, because thin rice is heated for a longer time, starch is easily dissolved in water, and can be easily absorbed in contact with digestive juices extensively after eating. In addition, thin rice is semi-fluid, and the emptying time of the stomach is shorter after eating, so it is easier to raise postprandial blood sugar by eating thin rice for breakfast than eating dry rice.
Finally, high postprandial blood glucose is also related to improper medication. Some patients with type 2 diabetes have obvious obesity and insulin resistance, but they have been using long-acting insulin promoters such as euglycemic agents, which are often difficult to control postprandial blood glucose because they take a long time to work and cannot improve the early-phase insulin secretion of diabetes well and reduce insulin resistance. In addition, when some patients use insulin, they mainly use medium- and long-acting insulin instead of combining with short-acting or ultra-short-acting insulin with fast onset, so the post-prandial blood sugar is also easy to be high.
So, how to control postprandial hyperglycemia? For the above reasons, the following aspects should be considered.
1, to strictly control the diet, pay attention to the quality and quantity of each meal and cooking methods, adhere to eat dry rice as the main breakfast, if you are not used to eating dry rice for breakfast, you can choose “ten grain rice” porridge, that is, brown rice, black glutinous rice, millet, buckwheat, gravy, oats, lotus seeds, cereals and red barley and other portions of the mixture, if you want to taste better, you can Add longan, raisins, etc. Use this coarse grains cooked porridge, can have a sense of satiety, the gastrointestinal absorption time is long, can maintain the stability of blood sugar.
2, pay attention to the monitoring of postprandial blood sugar, after the diagnosis of type 2 diabetes, not only need to regularly check fasting
Blood glucose and urine glucose, but also should not be afraid of the trouble to monitor postprandial blood glucose. For patients with type 2 diabetes, blood glucose should be checked daily when the disease is unstable, at least once a week for fasting and 2h after meals when the disease is stable, and at least once a month for fasting throughout the day, 2h after three meals, and before bedtime; at the same time, glycosylated hemoglobin (HbA.C) is an indicator that reflects the control of postprandial blood glucose, so attention should also be paid during daily monitoring. Therefore, when considering how well your diabetes is controlled, we should pay full attention to the overall control of blood glucose, rather than one-sidedly focusing on fasting blood glucose, or one-sidedly recognizing that fasting blood glucose is well controlled.
3, use drugs that can improve the first phase of insulin secretion, such as non-sulfonylurea insulin secretagogues such as Raglanet, Naglinet, rapid-acting insulin analogues such as NovoRel, these drugs can effectively improve the early phase of insulin secretion, in promoting insulin secretion has a dose-dependent and blood glucose concentration-dependent dual effect, due to its rapid metabolism, the occurrence of hypoglycemia is also greatly reduced, with a very good safety.
The newly developed glucagon-like peptide-1 (GLP-1) can also significantly improve the glycemic control of T2DM due to its effect of significantly improving first-phase insulin secretion and inhibiting glucagon release. In addition, among many antidiabetic drugs, α-glucosidase inhibitors are also a good drug to control postprandial hyperglycemia due to delaying postprandial carbohydrate uptake by competitively inhibiting α-glucosidase on small intestinal villi.
In conclusion, postprandial blood glucose has an important significance for diabetes and its related complications. Diabetic patients should not only pay attention to the monitoring of fasting blood glucose, but also tirelessly monitor the blood glucose 2 hours after meal, and pay attention to the control of diet and reasonable medication, only in this way can they obtain the ideal glycated hemoglobin level and also effectively prevent the occurrence of diabetes-related complications.