Giuliana When doing screening related to diabetes prevention, don’t just focus on fasting blood sugar in routine physical examinations. Glucose tolerance test, glycated hemoglobin, and fasting insulin are the core items that can detect the risk of diabetes 3-5 years in advance.
Don’t believe it. Last year, I accompanied my uncle to the endocrinology department. His fasting blood sugar during physical examinations for five consecutive years was around 5.5mmol/L, which was stuck in the normal range. During that time, he always felt dry mouth and drank no amount of water to quench his thirst. He also lost five or six kilograms. When I went to the hospital to check, his blood sugar had reached 12.8mmol/L 2 hours after a meal, and he was directly diagnosed with diabetes. The doctor who treated him said that he had impaired glucose tolerance at least 2 years ago. Unfortunately, he only checked his fasting blood sugar every time and found no abnormalities at all.
As for why routine fasting blood glucose is so easily missed? Nearly 70% of people with prediabetes in our country mainly have elevated blood sugar after meals, while fasting blood sugar is completely within the normal range. Only checking fasting means that most early risks are missed. If you don’t have any high-risk factors, it is enough to check your glycated hemoglobin every year during your physical examination. This indicator does not require fasting. It reflects your average blood sugar level in the past 2-3 months. It is equivalent to taking a "three-month average snapshot" of your blood sugar. It will not fluctuate greatly just because you ate hot pot or drank a cup of milk tea the day before. Many authoritative guidelines have now included it in the diagnostic criteria for diabetes. If it exceeds 6.5%, you must be highly vigilant. Of course, some doctors will remind that for people who have iron deficiency anemia or hemolytic anemia, the results of glycosylated hemoglobin will be biased. You cannot make a judgment based on this alone. It is best to look at it in conjunction with other indicators.
If you are in a high-risk group for diabetes, such as having a direct relative with diabetes, sitting for a long time, having waist and abdominal obesity, having high blood pressure and high blood lipids, or having gestational diabetes during a previous pregnancy, it is best to do an oral glucose tolerance test. Just drink a cup of standardized glucose water and measure the blood sugar levels on an empty stomach, 1 hour, and 2 hours after drinking sugar. Although it is a bit troublesome to go to the blood drawing station several times, it is the gold standard for diagnosing prediabetes and diabetes. If the blood sugar is stuck between 7.8-11.1mmol/L 2 hours after drinking sugar, it is considered impaired glucose tolerance. At this time, adjusting the diet and adding regular exercise can most of the time return to the normal state. When it really exceeds 11.1mmol/L, medication intervention is often needed.
You can also check fasting insulin. Many people have never heard of this item, but in fact, the earliest abnormality in type 2 diabetes is not an increase in blood sugar, but insulin resistance - to put it bluntly, the insulin in your body "gets lazy" and has to secrete several times more than usual to lower blood sugar to the normal range. Check fasting insulin at this time. If it exceeds the normal range, it means that insulin resistance has occurred. This signal appears 2-3 years earlier than the increase in blood sugar, and there is much room for intervention. There are several Internet practitioners around me who are in their early 30s. They usually eat takeout and stay up late. Their blood sugar is still within the normal range, but their fasting insulin has doubled the normal upper limit. After adjusting to a low-GI diet for three months and exercising for more than half an hour three times a week, they have returned to the normal range.
There is no need to do all the items at once. If you have a regular diet and rest, and there are no high-risk factors, it is enough to check fasting blood sugar and glycated hemoglobin every year. If there are really high-risk factors, you can consider adding the other two items. There is no need to over-check.
