The diagnosis of diabetes is not just a simple matter of elevated blood sugar, but involves a series of complex physiological changes and indicator detection. Through in-depth understanding of diabetes and its various testing methods, we can better grasp the panorama of the disease, so as to provide patients with more accurate and personalized diagnosis and treatment programs.
1、 Learn more about diabetes
diabetes, a seemingly common but complex disease, is a metabolic disease with high blood sugar as the main sign. Its production is due to defects in insulin secretion or impairment of its biological function, sometimes both of which coexist and jointly cause diseases. If high blood sugar persists, it will gradually erode our body like a chronic poison, especially the eyes, kidneys, heart, blood vessels, and nerves, leading to the gradual dysfunction of these tissues and even causing serious health problems.
The symptoms of diabetes vary according to its type. Patients with type 1 diabetes often have the typical symptoms of "more than three and less", that is, drinking more, urinating more, eating more and losing weight. When blood sugar levels are severely elevated, even leading to ketosis or ketoacidosis, the symptoms of "three more and one less" will become more pronounced.
Compared with type 1 diabetes, the symptoms of type 2 diabetes may be more insidious. Patients may experience symptoms such as fatigue, weakness, and obesity. It is particularly noteworthy that before the onset of type 2 diabetes, patients often have obesity. If timely diagnosis and treatment are not received at this time, the patient's weight may gradually decrease.
2、 Test method of diabetes
blood sugar detection: blood sugar is a key indicator for diagnosing diabetes. When the patient has obvious "three more and less" symptoms (that is, excessive drinking, urine, food and weight loss), as long as there is an abnormal blood sugar value, diabetes can be diagnosed. For patients without symptoms, blood sugar values need to be tested twice in a row. If both values exceed the normal range, they can be diagnosed as diabetes. In addition, for patients suspected of diabetes, doctors may require oral glucose tolerance test (OGTT) for further diagnosis.
Urine glucose test: Urine glucose often shows a positive result, especially when the blood glucose concentration exceeds the renal glucose threshold (approximately 160-180 milligrams per deciliter). However, the renal glucose threshold may be increased. In this case, even if the blood sugar reaches the diagnostic criteria for diabetes, the urine sugar may also be negative. Therefore, urine glucose measurement is not a diagnostic standard for diabetes.
Urine ketone body detection: When diabetes patients have ketosis or ketoacidosis, urine ketone will be positive.
Glycated hemoglobin (HbA1c) detection: This is the product of a non enzymatic reaction between glucose and hemoglobin, which is irreversible, so HbA1c levels are relatively stable. It can reflect the average blood glucose level over the past 2 months and is the most valuable indicator for evaluating blood glucose control status.
Glycated serum protein detection: This is the product of non enzymatic reaction between blood glucose and serum albumin, which can reflect the average blood glucose level in the past 1-3 weeks.
Serum insulin and C-peptide level detection: These two indicators can reflect the reserve function of pancreatic beta cells. In early or obese patients with type 2 diabetes, serum insulin may be normal or high. However, as the condition progresses, pancreatic function gradually declines and insulin secretion ability also decreases.
Blood lipid detection: diabetes patients are often accompanied by abnormal blood lipid, especially in the case of poor blood glucose control. Common blood lipid abnormalities include elevated levels of triglycerides, total cholesterol, and low-density lipoprotein cholesterol, as well as decreased levels of high-density lipoprotein cholesterol.
Detection of immune indicators: islet cell antibody (ICA), insulin autoantibody (IAA) and glutamic acid decarboxylase (GAD) antibody are three important indicators of humoral immune abnormalities in type 1 diabetes. Among them, the positive rate of GAD antibody is high and lasts for a long time, which is particularly significant for the diagnosis of type 1 diabetes. In addition, there is also a certain positive rate in the first-degree relatives of type 1 diabetes, which is of great significance for predicting the occurrence of type 1 diabetes.
Urinary albumin excretion detection (by radioimmunoassay or enzyme-linked immunosorbent assay): This method can sensitively detect the amount of albumin excretion in urine. In the early stage of diabetes nephropathy, urinary albumin may slightly increase. The monitoring of this indicator is very important for early detection and treatment of diabetes nephropathy.
3、 Diagnosis of diabetes
The diagnosis of diabetes is not complicated. When the fasting blood glucose value is greater than or equal to 7.0 mmol/L, or the blood glucose value two hours after meal is greater than or equal to 11.1 mmol/L, diabetes can be diagnosed. After diabetes is diagnosed, diabetes needs to be classified to determine the treatment plan.
The onset age of type 1 diabetes is usually relatively young. Most patients are under 30 years old. The onset of the disease is sudden, and the symptoms of excessive drinking, urine, food and weight loss are obvious. These patients have higher blood sugar levels, and some even present ketoacidosis as the initial symptom. In serum tests, insulin and C-peptide levels may be low, and ICA, IAA, or GAD antibodies may be positive, indicating that the patient needs to be treated with insulin.
Type 2 diabetes is more common in middle-aged and elderly people, especially obese people. The early symptoms of this type of diabetes are not obvious, and may only be mild fatigue, thirst and other symptoms. In cases of mild elevation of blood sugar, a glucose tolerance test is required to confirm the diagnosis. As the condition progresses, the serum insulin levels of late stage patients may decrease.
When making differential diagnosis, we need to consider the following situations:
Liver disease: Patients with cirrhosis may have abnormal glucose metabolism. In typical cases, fasting blood glucose levels are normal or low, while postprandial blood glucose levels rapidly increase. If the disease course is long, fasting blood sugar levels may also increase.
Chronic renal insufficiency: may lead to mild glucose metabolism abnormalities.
Stress states, such as cardiovascular and cerebrovascular accidents, acute infections, trauma, or surgical procedures, may lead to transient increases in blood sugar levels. After these stress factors are eliminated, blood sugar levels usually return to normal levels within 1-2 weeks.
Many endocrine diseases, such as acromegaly, Cushing's syndrome, hyperthyroidism, pheochromocytoma or glucagon tumor, may cause secondary diabetes. In addition to elevated blood sugar levels, these diseases may also exhibit other characteristic symptoms, which can help us with differential diagnosis.
The diagnosis and treatment of diabetes need to integrate a variety of detection methods and clinical indicators to ensure accuracy and timeliness. As patients and medical workers, we need to be highly alert to diabetes, and regularly conduct testing and evaluation to address this increasingly serious health challenge.