Ms. Liu has been suffering from diabetes for 6 years. Recently, she found that her blood sugar was high in the morning, reaching 8.6mmol/L. The doctor did not ask her to increase her insulin dose, but asked her to monitor her blood sugar 8 times throughout the day.
The next day, her blood sugar throughout the day was: fasting 8.8mmol/L; 2 hours after breakfast 7.9mol/L; before lunch 5.8mmol/L; 2 hours after lunch 8.2mmol/L; before dinner 5.3mmol/L; 2 hours after dinner, the blood sugar level was 7.2mmol/L; before going to bed, it was 6.2mmol/L; at 1:00 at night, the blood sugar level was 3.5mmol/L. After looking at the blood sugar monitoring results, the doctor not only did not agree with her to increase the insulin dose before dinner, but instead asked her to reduce the insulin dose before dinner by 2 units.
High blood sugar in the morning indicates insufficient insulin dosage. Why should we reduce the insulin dosage? Hence the following conversation.
Ms. Liu: For other patients around me, when fasting blood sugar increases in the morning, they increase the insulin dose and the blood sugar drops. And why do you want me to test my blood sugar first?
Doctor: There are two main causes of elevated fasting blood sugar in the morning: dawn phenomenon and Sumuji phenomenon. If blood sugar is well controlled at night, hypoglycemia does not occur, but blood sugar rises during a period of time in the early morning (from 3 a.m. to before breakfast), which is called the dawn phenomenon. Under normal circumstances, between 4 and 8 am, the secretion of some hormones that increase blood sugar (glucagon, growth hormone, glucocorticoids, etc.) in the human body gradually increases. When these hormones slowly increase, blood sugar rises accordingly, and more insulin is needed to maintain blood sugar within the normal range. Normal people's pancreatic islet B cells will automatically secrete more insulin to normalize blood sugar. Some patients with prediabetes have insufficient basal insulin secretion and lack of response to slow increases in blood sugar, and then blood sugar will rise. Diabetic patients have impaired pancreatic islet B cell function, especially patients with insulin-dependent diabetes whose blood sugar levels rise significantly in the early morning. Dawn phenomenon may also occur in patients with non-insulin-dependent diabetes. That is to say, as the secretion of glycemic hormone increases in the early morning, the body cannot effectively fight against it. At this time, fasting blood sugar rises in the early morning, which is the dawn phenomenon.
The second situation is different from the first. It manifests as low blood sugar at night and high blood sugar before breakfast. This is the "characteristic of low blood sugar first and then high blood sugar", which is called the "Sumujie phenomenon". "Hemogyet phenomenon" is the body's rebound hyperglycemia in the morning after hypoglycemia occurs at night. It usually occurs when blood sugar drops to a certain level after the dosage of anti-diabetic drugs (including insulin) is increased. In order to protect itself, the body increases the secretion of the above-mentioned glucagon hormone through a negative feedback regulation mechanism to resist further decline in blood sugar. Diabetic patients will experience morning hyperglycemia because their insulin cannot be increased accordingly.
Ms. Liu: According to the monitoring results of my blood sugar at 1 o'clock at night, which was 3.5mmol/L, and my fasting blood sugar, which was 8.8mmol/L, it should be "Sumujie's phenomenon." The insulin dose should be reduced, right?
Doctor: Yes! The treatment measures for "Sumujie Phenomenon" are:
① Reduce the dosage of insulin before dinner;
②When the blood sugar is close to the normal level before going to bed, you can eat a small amount appropriately.
Ms. Liu: So how should the dawn phenomenon be dealt with?
Doctor: The treatment measures for the "dawn phenomenon" are:
①Mixed injection of short-acting insulin and long-acting insulin before meals;
②Add intermediate-acting insulin before dinner or before going to bed. Among them, adding intermediate-acting insulin before going to bed has the best effect, because its peak action time is just before and after dawn, and it can fully supplement the body's demand for insulin at dawn;
③The insulin used before breakfast can be injected at 6 o'clock in the morning in advance to shorten the duration of hyperglycemia;
④Using insulin pump treatment, the amount of insulin input can be automatically adjusted according to the patient's blood sugar level. This is also the most ideal method at present. The disadvantage is that it is expensive and cannot be popularized.
When high blood sugar occurs in the morning, it is necessary to measure blood sugar at night first to distinguish between "sumujie phenomenon" and "dawn phenomenon". Low blood sugar at night is the "Sumoje phenomenon", and the dose of drugs (including insulin) should be reduced; in the latter, blood sugar is normal at night, but blood sugar is high in the morning, and the dose of drugs (including insulin) should be increased. If a similar situation occurs, do not blindly reduce the insulin dose and be sure to ask your doctor for advice.
