What is prediabetes? It is more reliable to do these three tests to screen for abnormal blood sugar!

Author: Li Guangwei, Chief Physician, Fuwai Hospital, Chinese Academy of Medical Sciences

Reviewer: Wu Xueyan, Chief Physician, Peking Union Medical College Hospital

Diabetes is one of the chronic diseases that seriously threaten human health. In recent years, the trend of younger people suffering from diabetes is more obvious, and the prevention and control of diabetes is urgent.

The typical symptoms of diabetes are three mores and one less: drinking more, urinating more, eating more, and losing weight. About half of diabetic patients do not actually have these typical symptoms, so they are not easy to detect and can only be discovered through blood sugar testing.

The World Health Organization's diagnostic criteria for diabetes are: fasting blood sugar ≥ 7mmol/L; or blood sugar ≥ 11.1mmol/L two hours after a meal; or glycosylated hemoglobin ≥ 6.5%. If any one of these is met, the patient can be diagnosed with diabetes.

The transition from a normal person to diabetes requires a process. At the beginning, blood sugar is completely normal. When you reach a certain age, under the influence of many high-risk factors, blood sugar slowly rises. The body will desperately secrete insulin to lower blood sugar, but one day it can no longer be suppressed and blood sugar suddenly rises.

When blood sugar is higher than that of healthy people but does not reach the diagnostic criteria for diabetes, this stage is called prediabetes.

Currently, venous plasma glucose testing is the globally recognized and most commonly used method for diagnosing diabetes and prediabetes.

The World Health Organization believes that the fasting blood sugar level of a normal person should be less than 6.1mmol/L. If the fasting blood sugar level is 6.1mmol/L≤ and less than 7.0mmol/L, it is considered impaired fasting blood sugar; if the blood sugar level is between 7.8mmol/L≤ and less than 2 hours after a meal and less than 11.0mmol/L, it is considered impaired glucose tolerance. Prediabetes includes high fasting blood sugar alone; high postprandial blood sugar alone; high fasting and postprandial blood sugar.

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There are many risk factors for diabetes, such as genetic factors, age, obesity, bad living habits, mental stress, poor sleep quality, etc. People with the above risk factors are at high risk of diabetes and prediabetes. You should pay close attention to your blood sugar level in order to detect prediabetes as early as possible.

It is generally believed that about 5%-10% of people with prediabetes will develop diabetes each year. The time from prediabetes to diabetes varies from person to person, ranging from half a year to 5-10 years. If timely and effective intervention is carried out, the possibility of conversion to diabetes can be significantly reduced. Effective management of people with prediabetes is the key to preventing the occurrence and development of diabetes.

If only fasting blood sugar is high or only postprandial blood sugar is high, there are relatively few risk factors for diabetes, and the risk of developing diabetes is relatively low. If both fasting blood sugar and blood sugar two hours after a meal are high, the risk of developing diabetes will be higher. If you also have other underlying diseases such as high blood pressure, high blood lipids, fatty liver, etc., the speed of prediabetes progressing to diabetes will be faster.

Prediabetes is caused by obesity, mental stress, lack of exercise and other reasons. If bad lifestyle habits can be corrected in time, most people may be able to reverse the prediabetes state. This is also the importance of emphasizing the concept of prediabetes.

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Improving lifestyle habits includes eating a healthy diet, doing at least 30 minutes of moderate-intensity exercise every day (including brisk walking, running, swimming, etc.), maintaining a normal body weight, ensuring 7-8 hours of sleep every day, maintaining normal blood pressure and blood lipids, avoiding excessive tension and excessive mental stress, etc. Through hard work, if prediabetes has been reversed, you still need to maintain good lifestyle habits in order to achieve the goal of long-term reversal.

If these measures still fail to control blood sugar, or if it is difficult to stick to them, the risk of developing prediabetes into diabetes will be higher, and the use of hypoglycemic drugs can also help reverse high blood sugar. If it has already progressed to diabetes, it is very difficult to reverse it.

If you want to detect abnormal blood sugar levels in a timely and early manner, you should pay attention to regular screening. Physical examinations usually involve drawing blood to test fasting blood sugar and glycosylated hemoglobin.

The biggest advantage of fasting blood sugar is that it is reliable, because after fasting for 8-12 hours, blood sugar is basically at a relatively low level and very stable. If fasting blood sugar is high, it means there is a problem. Although fasting blood sugar is relatively accurate, it is easy to miss about half of the people with abnormal blood sugar by only measuring fasting blood sugar. Because fasting blood sugar is normal, postprandial blood sugar is abnormal, which accounts for about half of the people with impaired glucose tolerance.

The characteristic of blood sugar 2 hours after a meal is that it is not very stable and is related to the type and amount of food eaten. The same person may have different blood sugar levels after eating different foods.

Glycated hemoglobin represents the average blood sugar level in the past three months. If the postprandial blood sugar value reaches the diagnostic criteria for diabetes, it is possible that the glycated hemoglobin is less than 6.5%, but may be 6.4% or 6.3%. Because blood sugar fluctuates greatly, the average value is not high, but it is very high at a certain point in time, which is also diabetes.

Therefore, if only fasting blood sugar and glycosylated hemoglobin are tested, many diabetic patients will be missed. If you are a high-risk group for diabetes, over 40 years old, have a family history of diabetes, have had gestational diabetes, do not like to exercise, have abnormal blood pressure and blood lipids, and have several risk factors, the examination should be more comprehensive, and fasting blood sugar, 2-hour postprandial blood sugar, and glycosylated hemoglobin should all be tested. If you are very young, in your twenties, and have no family history of diabetes, you have fewer risk factors, and you can just test your fasting blood sugar once a year.