Misunderstanding 1: Measuring blood sugar only measures one “point”
Antidiabetic treatment must be carried out according to various abnormal blood sugar conditions within 24 hours. Without blood glucose testing, treatment will become blind and may even lead to serious consequences.
Many patients only test blood sugar before and after breakfast, but blood sugar in the human body actually changes 24 hours a day. In clinical practice, we can see that some patients mainly have high fasting blood sugar, some have mainly high postprandial blood sugar, some have mainly high blood sugar in the morning, some have mainly high blood sugar in the afternoon, and some have high blood sugar at night. Mainly, the time point of monitoring blood sugar is very important. There are currently no absolute rules on when to measure blood sugar.
In order to understand the condition, doctors generally recommend measuring blood sugar 7 times a day. The 7-time blood sugar generally refers to blood sugar before three meals, 2 hours after meals and blood sugar before going to bed. There are also four blood glucose levels that are more commonly used in clinical practice, usually referring to blood glucose levels before breakfast, 2 hours after breakfast, 4:00-5:00 pm, and 2 hours after dinner or before going to bed. For patients who repeatedly experience high blood sugar before breakfast, they need to measure their blood sugar at night. Generally, the time period between 2:00 and 3:00 is chosen to measure blood sugar at night. Diabetic patients should check their blood sugar immediately when they feel unwell and have signs of acute complications. In more serious cases, it is best to use 24-hour or even 72-hour continuous blood glucose monitoring.
Misunderstanding 2: Frequency of blood glucose testing is too high or too low
Most of the blood glucose testing methods currently used are invasive, and frequent blood sample collection will increase mental burden and stress on patients. Generally speaking, only some patients need to test their blood sugar 4 to 7 times a day under certain circumstances. These people include patients who have just been diagnosed with diabetes, patients who are hospitalized and need to adjust their treatment plan, and patients with other acute diseases and high fasting blood sugar.
For most patients whose condition is stable, they can refer to the trilogy of blood glucose monitoring by Director Tian Hui of the Geriatric Endocrinology Department of the Chinese People's Liberation Army General Hospital (301 Hospital), and measure it every day, but you can skip to choose, for example, measure breakfast and dinner today. Blood sugar 2 hours before and after breakfast, tomorrow before breakfast and lunch and 2 hours after lunch, blood sugar before breakfast and 2 hours after three meals the day after tomorrow; after blood sugar control is stable, reduce the frequency of monitoring to 2 to 3 days a week ; After blood sugar control reaches the target, without changing the diet ratio arbitrarily, blood sugar should be measured 2 to 5 times a week, and different time points can be selected. Especially when changing lifestyle, blood sugar should be monitored in time.
For patients with gestational diabetes and juvenile diabetes, blood glucose testing should be more frequent. Even if the condition is stable, blood glucose needs to be tested at least 4 to 7 times a week. Please consult an endocrinologist for details.
Misunderstanding 3: Stop taking hypoglycemic drugs without permission before testing
For most patients, testing blood sugar is to observe the effect of treatment, and there is no need to specifically stop taking anti-diabetic drugs and other drugs being used before testing. However, many patients are accustomed to going to hospital outpatient clinics in the morning to test fasting blood sugar. Since it may take a long time, it is best not to take anti-diabetic drugs or insulin before going out to avoid hypoglycemia. However, other drugs such as anti-hypertensive drugs should still be used. Take it as usual. After testing fasting blood glucose, patients should take antidiabetic drugs or insulin in a timely manner, and then eat breakfast according to their usual habits. Patients should be reminded here that it is best to bring medicines, water and convenient breakfast when going to the hospital.
If blood glucose is measured to evaluate pancreatic islet function, it is generally necessary to stop taking antidiabetic drugs and insulin, as well as other drugs that may affect glucose metabolism. In this case, it is recommended that the patient consult an endocrinologist first, and it is best not to decide to stop taking the medication on his own.
Misunderstanding 4: "After a meal" means counting starts after finishing the meal
Postprandial blood sugar generally refers to blood sugar 2 hours after a meal, usually starting from the first bite of a meal, not 2 hours after a meal as is often mistakenly thought. Blood glucose 2 hours after a meal is mainly used for the diagnosis of diabetes and evaluation of drug efficacy. For normal people, blood sugar should have dropped to the normal range 2 hours after a meal; if blood sugar remains high 2 hours after a meal, after excluding stress conditions, it is generally considered abnormal and can be seen in impaired glucose tolerance or diabetes. .
Since the blood sugar peak after a meal may be earlier or delayed, depending on the patient's specific situation, the doctor may also recommend testing blood glucose 1 hour after the meal, 1.5 hours after the meal, and 3 hours after the meal. Fasting blood sugar and postprandial blood sugar are equally important. Therefore, it is recommended that patients go to the hospital in the morning to have their fasting blood sugar tested, then resume taking medication and eating, and wait 2 hours to test their postprandial blood sugar.
Misunderstanding 5: Use urine glucose testing instead of blood glucose testing
Generally, when blood sugar is greater than 10.0mmol/L, urine sugar may appear because it exceeds the renal glucose threshold. At this time, detecting urine sugar can indirectly reflect blood sugar levels. In the past, the Bancroft test was used to detect urine sugar, but now urine glucose test strips are often used to self-test urine sugar.
Because this method is simple, quick, non-invasive, painless, and cheap, it is easily accepted by patients. In clinical practice, we often see parents who feel sorry for their children and only test urine sugar. This method has great limitations, and the test results are also susceptible to interference and very inaccurate. Therefore, urine glucose monitoring cannot be used as an indicator for disease monitoring, nor can it be used as an indicator for evaluating drug efficacy.
Blood glucose testing reflects the blood glucose concentration when blood is taken, while urine sugar reflects the average sugar concentration when urine accumulates in the bladder, and is greatly affected by urine volume. If a diabetic patient has bladder autonomic neuropathy, there will be urinary retention. If the urine of different periods is mixed, the blood sugar level during the period of urinary retention cannot be accurately reflected. At the same time, due to individual differences in renal glucose threshold, it can directly affect the amount of urinary glucose excretion.
In some pregnant women, the renal glucose threshold is lowered, and urine glucose may appear even when blood sugar is normal; while in some patients, such as patients with diabetic nephropathy, the renal glucose threshold is elevated, and when blood glucose has significantly increased, urine glucose may still be negative. In addition, there are some pseudodiabetes, which will interfere with the accuracy of the results. Therefore, urine glucose testing should never be used as a substitute for blood glucose testing.
