Scientific Understanding of Blood Glucose Regulation Mechanisms and Comprehensive Management Guidelines

Blood Glucose and its Regulation

1. What is blood glucose, and where does it come from?

Blood glucose refers to glucose in the blood. Most of the energy required for the activities of cells in the body comes from glucose. Blood glucose must be maintained at a certain level to meet the needs of various organs and tissues. Carbohydrates in food are digested and broken down into glucose, which is then absorbed into the bloodstream and transported to cells throughout the body. Blood glucose serves as an energy source, and a portion is converted into liver glycogen or muscle glycogen and stored in the liver and muscles, respectively. However, the capacity of cells to store liver glycogen is limited. If too much glucose is ingested, the excess sugar will be converted into fat. Between meals, stored liver glycogen can be broken down into glucose to maintain a normal blood glucose concentration. During strenuous exercise or after a long period without food replenishment, liver glycogen will be quickly depleted. At this time, cells will break down fat to supply the energy needed by the body. The human brain and nerve cells must be powered by glucose. When necessary, the body can also convert its own proteins (such as those in muscles, skin, and even organs) into glucose to ensure energy supply for survival.

2. What regulates the stability of blood glucose levels? Blood glucose regulation is handled by a pair of conflicting hormones: insulin and glucagon. When blood glucose levels drop, the alpha cells of the pancreas secrete glucagon, mobilizing glycogen reserves in the liver to break down into glucose and release it into the bloodstream, causing blood glucose levels to rise. When blood glucose levels are too high, the beta cells of the pancreas secrete insulin, promoting the conversion of glucose into liver glycogen reserves or its utilization by tissue cells. Diabetes develops because the ability of beta cells to secrete insulin weakens, resulting in lower insulin levels and an inability to lower blood glucose.

3. What is the normal range for blood glucose?

In a healthy state, fasting blood glucose is generally 3.9–6.1 mmol/L (70–110 mg/dL), and 2-hour postprandial blood glucose is less than 7.8 mmol/L (140 mg/dL).

4. How is blood glucose measured?

To understand your blood sugar levels, you can have your blood drawn for testing at a hospital or medical examination center, or you can use a portable blood glucose meter for self-testing. Diabetic patients, in particular, should have one and monitor their blood sugar levels regularly. Home portable blood glucose meters are generally very convenient and easy to use, displaying results in just one minute.

5. What environmental factors can affect blood sugar levels?

Blood sugar levels are not constant throughout the day; they fluctuate regularly throughout the day, depending on meal intake. In addition, blood sugar levels are affected by the following environmental factors:

(1) Climate: Cold stimulation in winter can promote adrenaline secretion and increase glycogenolysis. Hot and sweaty summers can lead to blood concentration, causing elevated blood sugar levels.

(2) Infection, trauma, surgery, fever, severe psychological trauma, vomiting, insomnia, anger, anxiety, irritability, fatigue, and stressful situations such as acute myocardial infarction can cause a rapid increase in blood sugar and may even induce diabetic ketoacidosis.

(3) Sudden changes in work or living environment can lead to temporary maladaptation of the body, causing a rise in blood sugar.

(4) Diet: The state of the food consumed and its glycemic index can both affect blood sugar levels.