The fasting blood glucose we usually refer to is the blood glucose after 8~12 hours of fasting, that is, the blood glucose in the early morning fasting state, the blood glucose before lunch and dinner is not included in this list. It is best to measure fasting blood glucose in the early morning from 6:00 to 8:00 a.m., without using glucose-lowering drugs, eating breakfast or exercising before the measurement, so that some influencing factors can be excluded to a greater extent and the true condition can be reflected. However, we often find that the fasting blood glucose results of some patients are not true and do not reflect the real blood glucose situation, including patients who monitor themselves at home or take blood test at the hospital. What factors can lead to untrue fasting blood sugar results, you must know. 1. Dietary factors Eating a lot of badly digested food at night or having dinner too late (too late will lead to less than 8 hours of fasting time) may lead to high fasting blood glucose value in the next morning. In addition, some patients will intentionally eat less staple food the night before the test in order to get a better fasting glucose result, which makes the fasting glucose value lower than usual again. Therefore, to ensure the authenticity of fasting blood glucose in the early morning of the next day, dinner must be kept in a usual state. 2. Time factor The measurement of fasting blood glucose must be completed before 8:00 am. However, there is often this situation: many patients, in order to ask the expert to see the doctor, do not eat or drink in the morning to rush from home to the hospital, and then register for consultation, and often have to wait until after 9:00~10:00 a.m. to see the doctor’s turn to measure blood glucose. At this time, although the patient is in fasting state, but by the influence of the biological clock, glucagon has gradually increased after 8:00, even if they do not eat, blood sugar will also rise. Therefore, the blood sugar measured at this time is not the real fasting blood sugar, but only the random blood sugar. In addition, some patients walk a long distance to the hospital, so the measured blood glucose may be lower than usual; if they encounter long waiting time, unhappy mood, emotional excitement, etc., the blood glucose may rise again. For type 1 diabetic patients, delayed or postponed insulin injection in the morning may lead to a significant increase in blood glucose. The blood glucose measured under the above circumstances is not really fasting blood glucose. Therefore, it is recommended that patients should finish the fasting blood glucose test at home or in the nearby community health center, eat, take medication or take insulin, and then go to the hospital for consultation. 3. Exercise factor Inappropriate morning exercise is a common cause of fasting blood glucose. So we ask that when checking fasting blood sugar, it should be done without doing morning exercise. Because blood glucose will generally fall after exercise, if blood glucose instead rises it may be that mild hypoglycemia occurred during exercise, and hypoglycemia in turn leads to reactive blood glucose rise. These are untrue fasting blood sugar results. Many people like to exercise in the morning before eating breakfast, this practice is unscientific and easy to trigger hypoglycemia, it is better to eat some food before the morning exercise. Pay attention to check the blood sugar before and after exercise during morning exercise in order to find out an appropriate amount of exercise. 4.Drug factors Drug is an important factor affecting fasting blood sugar results. If the dose of insulin is too large in the evening, which leads to the phenomenon of Sumuje, it will also make the fasting blood sugar abnormally high in the early morning. Then again, some patients find that fasting blood sugar is high, they intentionally eat less breakfast or add mealtime hypoglycemic drugs, so that the phenomenon of fasting blood sugar is higher than that of 2 hours after breakfast. There are also patients who take health care products containing hypoglycemic drugs, which will also affect fasting or postprandial blood sugar. 5, sleep factor American scientists divided the sleep time of a day into three categories: sleep <6 hours, sleep in 6~8 hours, sleep >8 hours, to observe the effect of sleep time on blood sugar. During the six-year study period, it was found that those who slept <6 hours a day had 4.56 times more blood sugar conversion from normal to abnormal fasting blood sugar than those who slept in 6~8 hours. There was no difference between those who slept >8 hours and those who slept between 6 and 8 hours. It can be seen that diabetic patients who sleep <6 hours per night are prone to abnormal fasting glucose. To get the true fasting glucose, ensure sufficient sleep time the night before. 6. Stress factors Recent bad mood, anxiety and depression, insomnia and dreaminess may lead to higher than usual fasting blood sugar, which cannot reflect the true drug effect or condition. In addition, if acute infection or trauma occurs, blood glucose will often rise due to stress factors. Some patients have gastroenteritis, nausea and vomiting and cannot eat, so they stop taking medication. Some patients think that they do not need to inject insulin if they do not eat, thus leading to serious hyperglycemia ...... The fasting blood glucose measured under these circumstances cannot reflect the real basic fasting blood glucose and must be treated symptomatically instead of adjusting hypoglycemic medication. 7, monitoring methods and blood glucose meter factors This is an extremely common factor that affects the truthfulness of fasting blood glucose, and is often mentioned by us. The incorrect monitoring method when patients use blood glucose meter, the blood glucose meter itself is not qualified or has not been corrected for a long time, the test paper is past the expiration date, the quality is not up to standard, etc. will affect the blood glucose results.