Diabetes mellitus is a group of metabolic diseases characterized by high blood sugar. Hyperglycemia is caused by a defect in insulin secretion, impaired biological action, or both. The long-standing hyperglycemia in diabetes leads to chronic damage and dysfunction of various tissues, especially the eyes, kidneys, heart, blood vessels, and nerves.

Diabetes is a common metabolic disorder in which blood sugar (glucose) rises and then runs out of the urine, so there is sugar in the urine. Specifically, it is related to excessive intake of total calories, fat, carbohydrates, less exercise, and overnutrition, so it is called "wealth disease". If the disease is not well controlled, it can cause complications in the future.

pathogen

1. Genetic factors

There is significant genetic heterogeneity in both type 1 and type 2 diabetes. There is a tendency for diabetes to run in families, and 1/4~1/2 of patients have a family history of diabetes. Clinically, there are at least 60 or more genetic syndromes that can be accompanied by diabetes. There are multiple DNA loci involved in the pathogenesis of type 1 diabetes, among which the DQ polymorphism in the HLA antigen gene is the most closely related. A variety of definite genetic mutations have been found in type 2 diabetes, such as insulin gene, insulin receptor gene, glucokinase gene, mitochondrial gene, etc.

2. Environmental factors

Obesity due to overeating and reduced physical activity is the most important environmental factor in type 2 diabetes, making individuals with a genetic predisposition to type 2 diabetes. People with type 1 diabetes have abnormalities in the immune system that cause an autoimmune response that destroys insulin β cells after infection with certain viruses such as coxsackievirus, rubella virus, mumps virus, etc.

Clinical presentation

1. Polydipsia, polyuria, polyphagia and weight loss

Severe hyperglycemia presents with typical symptoms of "three more and one less", which is more common in type 1 diabetes. In ketosis or ketoacidosis, the symptoms of "three more and one less" are more pronounced.

2. Fatigue, weakness, obesity

It is more common in type 2 diabetes. Type 2 diabetes is often preceded by obesity and can lead to gradual weight loss if not diagnosed in time.

examine

1. Blood sugar

It is the only criterion for diagnosing diabetes. Patients with obvious symptoms of "three more and one less" can be diagnosed with only one abnormal blood glucose value. Asymptomatic people need two abnormal blood glucose levels to diagnose diabetes. If suspected, a 75g glucose tolerance test should be done.

2. Urine sugar

Often positive. When the blood glucose concentration exceeds the renal glucose threshold (160~180 mg/dL), urine glucose is positive. When the renal glucose threshold is elevated, the diagnosis of diabetes may be negative, even when blood glucose is reached. Therefore, urine glucose measurement is not used as a diagnostic criterion.

3. Urine ketone bodies

Positive urine ketones in ketosis or ketoacidosis.

4. Glycosylated hemoglobin (HbA1c)

It is a product of non-enzymatic reaction between glucose and hemoglobin, the reaction is irreversible, and the HbA1c level is stable, which can reflect the average blood glucose level in the 2 months before blood collection. It is the most valuable indicator for judging the status of blood glucose control.

5. Glycation of serum proteins

It is a product of the non-enzymatic reaction of blood glucose and serum albumin, reflecting the average blood glucose level 1~3 weeks before blood collection.

6. Serum insulin and C-peptide levels

Reflects the reserve function of pancreatic islet β cells. Serum insulin is normal or elevated in early stage 2 diabetes or obese diabetes, and as the disease progresses, the islet function gradually decreases, and the ability to secrete insulin decreases.

7. Blood lipids

Dyslipidemia is common in patients with diabetes, especially in the presence of poor glycemic control. Manifests as elevated levels of triglycerides, total cholesterol, and low-density lipoprotein cholesterol. HDL cholesterol levels are lowered.

8. Immunization indicators

Pancreatic islet cell antibody (ICA), insulin autoantibody (IAA) and glutamate decarboxylase (GAD) antibody are three important indicators of humoral immunity abnormalities in type 1 diabetes, among which GAD antibody has a high positive rate, a long duration, and great diagnostic value for type 1 diabetes. There is also a certain positive rate in first-degree relatives of type 1 diabetes, which has the significance of predicting type 1 diabetes.

9. Urine albumin excretion, radioimmune or enzyme-linked method

Urine albumin excretion can be detected sensitively, and urine albumin is mildly elevated in early diabetic nephropathy.

diagnosis

The diagnosis of diabetes mellitus is generally not difficult, and is diagnosed by fasting blood glucose greater than or equal to 7.0 mmol/L and/or 11.1 mmol/L at two hours after meals. After diagnosing diabetes, it is classified:

1.1 type diabetes

The age of onset is young, most of them are < 30 years old, the onset is sudden, the symptoms of polydipsia, polyuria, polyphagia and weight loss are obvious, the blood sugar level is high, many patients have ketoacidosis as the first symptom, the serum insulin and C-peptide levels are low, and ICA, IAA or GAD antibodies can be positive. Oral drugs alone are ineffective and require insulin therapy.

2.Type 2 diabetes

It is common in middle-aged and elderly people, and the incidence of obesity is high, and it can often be accompanied by hypertension, dyslipidemia, arteriosclerosis and other diseases. Symptoms are insidious, there are no symptoms in the early stage, or there is only mild fatigue, thirst, and no obvious increase in blood glucose, and glucose tolerance test is done to confirm the diagnosis. Serum insulin levels are normal or elevated in the early stages and low in the late stages.

differential diagnosis

1. Liver disease

Patients with cirrhosis often have abnormal glucose metabolism, typically normal or low fasting blood glucose, and a rapid rise in blood glucose after meals. Fasting blood glucose may also be elevated in older adults.

2. Chronic renal insufficiency

Mild abnormalities of glucose metabolism may occur.

3. Stress state

Many stress states such as cardiac and cerebrovascular accidents, acute infections, trauma, and surgical operations may lead to a transient increase in blood sugar, which can be recovered in 1~2 weeks after the stress factors are eliminated.

4. A variety of endocrine diseases

For example, acromegaly, Cushing's syndrome, hyperthyroidism, pheochromocytoma, and glucagonoma can cause secondary diabetes, and in addition to elevated blood glucose, there are other characteristic manifestations that are not difficult to distinguish.

treat

There is no cure for diabetes, but it can be controlled with a variety of treatments. There are 5 main areas: education of diabetic patients, self-monitoring of blood sugar, dietary therapy, exercise therapy and medication.

(1) General treatment

1. Education

It is necessary to educate diabetic patients to understand the basic knowledge of diabetes, establish confidence in overcoming the disease, how to control diabetes, and control the health benefits of diabetes. Appropriate treatment plans are developed according to the characteristics of each diabetic patient.

2. Self-monitor your blood sugar

With the increasing popularity of small rapid blood glucose meters, patients can adjust the dose of hypoglycemic drugs at any time according to their blood sugar levels. Monitor blood glucose at least 4 times a day (before meals) and 8 times when blood glucose is unstable (before meals, after meals, before bedtime, and at 3:00 a.m.) for intensive treatment of type 1 diabetes. Fasting blood glucose should be controlled below 7.2 mmol/L during intensive treatment, blood glucose should be less than 10 mmol/L at two hours after meals, and HbA1c should be less than 7%. The frequency of self-monitoring of blood glucose in patients with type 2 diabetes can be appropriately reduced.

(2) Medication

1. Oral medication

(1) Sulfonylureas can be used for patients with type 2 DM who are not satisfied with the efficacy after diet control, exercise, weight reduction, etc. Because the hypoglycemic mechanism is mainly to stimulate insulin secretion, it has a good effect on patients with certain pancreatic islet function. It also has a certain effect on some diabetic patients who are young at onset and not fat in the early stage. However, when using sulfonylureas in obese patients, special attention should be paid to dietary control, so that the weight is gradually reduced, and it is better to combine it with biguanides or α-glucosidase inhibitors hypoglycemic drugs. The following conditions are contraindicated: first, severe liver and kidney insufficiency; second, with severe infection, trauma and major surgery, temporarily switch to insulin therapy; the third is to temporarily switch to insulin therapy during diabetic ketosis and ketoacidosis; Fourth, diabetic pregnant women, pregnancy hyperglycemia has a teratogenic effect on the fetus, and the incidence of preterm birth and stillbirth is high, so blood sugar should be strictly controlled, and the fasting blood glucose should be controlled below 105 mg/dL (5.8 mmol/L), and the blood sugar should be controlled below 120 mg/dL (6.7 mmol/L) 2 hours after meals, but oral hypoglycemic drugs should not be used to control blood sugar; Fifth, allergy to sulfonylureas or obvious adverse reactions.

(2) The main mechanism of biguanide hypoglycemic drugs to lower blood sugar is to increase the utilization of glucose in peripheral tissues, increase the anaerobic digestion of glucose, reduce the absorption of glucose in the gastrointestinal tract, and reduce body weight. (1) Indications for obese type 2 diabetes, unsatisfactory with diet alone; For type 2 diabetes, sulfonylureas alone are not effective, and biguanides can be added; Type 1 diabetes mellitus is treated with insulin and the insulin dose can be reduced with biguanides; When insulin therapy is switched to secondary failure in type 2 diabetes, biguanides can be added to reduce insulin dose. (2) Contraindications: severe liver, kidney, heart, lung diseases, wasting diseases, malnutrition, hypoxic diseases; diabetic ketosis, ketoacidosis; When accompanied by severe infection, surgery, trauma and other stressful conditions, biguanides should be suspended and insulin therapy should be switched; Gestation period. (3) Adverse reaction: One is gastrointestinal reaction. The most common manifestations are nausea, vomiting, decreased appetite, abdominal pain, and diarrhoea, which can occur in up to 20% of patients. To avoid these adverse effects, the drug should be taken during or after meals. The second is headache, dizziness, and metallic smell. The third is lactic acidosis, which is more common in long-term and large-scale use of hypoglycemic products, accompanied by liver and kidney function decline, hypoxic diseases, acute infection, gastrointestinal diseases, and the chance of acidosis caused by hypoglycemic tablets is less.

(3) α glucosidase inhibitors can be used in both type 1 and type 2 diabetes, and can be combined with sulfonylureas, biguanides or insulin. (1) Voglibose is taken orally immediately before meals. (2) Acarbose is taken orally immediately before meals. The main adverse reactions were: abdominal pain, intestinal flatulence, diarrhea, and increased anal gas.

(4) Insulin sensitizers have the effect of enhancing insulin and improving glucose metabolism. It can be used alone or in combination with sulfonylureas, biguanides, or insulin. Patients with liver disease or cardiac insufficiency should not use it.

(5) Meglitinide insulin secretagogue (1) Repaglinide is a rapid insulin secretagogue, which is taken orally immediately before a meal, and is taken at each main meal, without meals. (2) Naglinide is similar to repaglinide.

2. Insulin therapy

Insulin preparations include animal insulin, human insulin, and insulin analogues. According to the time of action, it is divided into short-acting, intermediate-acting and long-acting insulin, and has been made into mixed preparations, such as Novolin 30R, Humulin 70/30.

(1) Type 1 diabetes needs to be treated with insulin. Non-intensive patients are injected 2~3 times a day, and those on intensive treatment are injected 3~4 times a day, or treated with an insulin pump. Dose adjustments are required frequently.

(2) For patients with type 2 diabetes mellitus oral hypoglycemic drugs failing, the combination treatment method is to use the original oral hypoglycemic drug dose unchanged, inject intermediate-acting insulin or long-acting insulin analogues at 10:00 p.m. before bedtime, generally adjust once every 3 days, the purpose is to reduce fasting blood glucose to 4.9~8.0 mmol/L, and those who are ineffective stop taking oral hypoglycemic drugs and inject insulin twice a day.

The greatest adverse effect of insulin therapy was hypoglycemia.

(3) Exercise therapy

Increased physical activity improves the body's sensitivity to insulin, lowers body weight, reduces body fat mass, increases physical strength, improves work capacity and quality of life. The intensity and duration of exercise should be determined according to the patient's general health, and the amount of exercise that is appropriate for the patient and the items that the patient is interested in should be found. Exercise can take various forms, such as walking, brisk walking, aerobics, dancing, tai chi, running, swimming, etc.

(4) Dietary therapy

Diet therapy is the basis of the treatment of various types of diabetes, and some patients with mild diabetes can control the disease with diet alone.

1. Total calories

The total caloric requirement should be determined based on a combination of factors such as the patient's age, gender, height, weight, physical activity, and medical condition. First of all, the standard weight of each person can be calculated according to the following formula: standard weight (kg) = height (cm) - 105 or standard weight (kg) = [height (cm) - 100]×0.9; It can also be obtained by age, gender, and height lookup. After calculating the standard weight, the caloric requirement per kilogram of standard body weight is estimated based on the daily physical activity of each person.

After calculating the daily calorie requirement based on the standard body weight, it should be adjusted accordingly according to the patient's other conditions. Children, adolescents, lactation, malnutrition, wasting, and chronic wasting disease should increase total calories as appropriate. Obese people should strictly limit the total calorie and fat content, give a low-calorie diet, the total calories per day do not exceed 1500 kcal, generally reduce 0.5~1.0kg per month, and when close to the standard weight, then calculate the total calories per day according to the above method. In addition, older people need fewer calories than younger people, and adult women need fewer calories than men.

2. Carbohydrates

Carbohydrates produce 4 kilocalories per gram, which is the main source of calories, and it is now believed that carbohydrates should account for 55%~65% of the total calories in the diet, which can be calculated by the following formula:

According to the living habits of the Chinese people, 250~400g of staple food (rice or noodles) can be eaten, and the following preliminary estimates can be made, the staple food of resting people is 200~250g per day, 250~300g of light manual laborers, 300~400g of moderate physical laborers, and more than 400g of heavy physical laborers.

3. Protein

Protein produces 4 kcal per gram. It accounts for 12%~15% of the total calories. The protein requirement is about 1g per kilogram of body weight in adults. In children, pregnant women, lactating women, malnutrition, emaciation, and wasting diseases, it should be increased to 1.5~2.0g per kilogram of body weight. Patients with diabetic nephropathy should reduce their protein intake to 0.8 g per kilogram of body weight, and if they have pre-existing renal insufficiency, they should consume high-quality protein, and the intake should be further reduced to 0.6 g per kilogram of body weight.

4. Fat

Fats are higher in energy, producing 9 kcal per gram. It accounts for about 25% of the total calories, generally not more than 30%, and is 0.8~1g per kilogram of body weight per day. Animal fats mainly contain saturated fatty acids. Vegetable oil contains a lot of unsaturated fatty acids, and diabetic patients are prone to atherosclerosis, so vegetable oil should be used.