A Detailed Explanation of the Five Pillars of Diabetes Classification, Diagnosis, and Comprehensive Management

Diabetes-related issues

diabetes

Diabetes mellitus is a group of metabolic diseases characterized by chronic hyperglycemia, caused by defects in insulin secretion and/or action. Long-term abnormal glucose metabolism leads to metabolic disorders, resulting in various complications, such as chronic progressive lesions in organs and tissues including the heart, blood vessels, eyes, kidneys, and nerves. In severe cases, it can even lead to diabetic ketoacidosis and hyperosmolar hyperglycemia syndrome. If treatment is not timely, the mortality rate is very high, seriously endangering health and requiring high attention and focused prevention and control.

I. Classification of Diabetes

The internationally accepted classification criteria are those proposed by the WHO Expert Committee on Diabetes (1999).

(1) Type 1 diabetes mellitus (T1DM). Due to the destruction of pancreatic β cells, there is an absolute lack of insulin, which can be either immune-mediated or idiopathic.

(2) Type 2 diabetes mellitus (T2DM). From being mainly characterized by insulin resistance with progressive insulin deficiency, to being mainly characterized by progressive insulin deficiency with insulin resistance.

What is insulin resistance? Insulin resistance refers to a decrease in the sensitivity and responsiveness of insulin's target organs (mainly skeletal muscle, adipose tissue, and liver) to insulin, resulting in a reduced uptake and utilization of glucose. This causes a normal amount of insulin to produce a lower physiological effect than normal. This phenomenon is called insulin resistance.

(3) Special types of diabetes. These are diabetes caused by other factors such as genetic defects in pancreatic β-cell function, genetic defects in insulin action, pancreatic exocrine diseases (such as cystic fibrosis), and drug or chemical causes (such as treatment for AIDS or after organ transplantation).

(4) Gestational diabetes mellitus (GDM). This refers to the development of varying degrees of glucose metabolism abnormalities during pregnancy in women who had normal glucose metabolism or potential glucose intolerance before pregnancy but were not diagnosed. It usually occurs in the mid-to-late stages of pregnancy and generally presents with only mild, asymptomatic hyperglycemia.

Some patients cannot be clearly classified as type 1 or type 2 diabetes. Their clinical manifestations and disease progression have characteristics of both types. For example, some patients present with T2DM and may have ketoacidosis. Similarly, some patients with T1DM may have autoimmune disease manifestations, but their onset is late and the progression is slow. This can be seen in children, adolescents and adults. The accurate diagnosis will be determined over time.

II. Current Incidence of Diabetes

In recent years, due to social development, changes in diet and exercise patterns, and other factors, the incidence of diabetes has been rising continuously. According to reports, data from the 8th edition of the International Diabetes Federation's (IDF) Global Diabetes Atlas released in 2017 shows that there are currently 425 million adults (aged 20-79) with diabetes worldwide, with an estimated prevalence of 8.8%. It is projected that by 2045, the number of people with diabetes may reach 629 million, with China having the largest number of adult diabetes patients at 114 million, accounting for more than a quarter of the global total. This number continues to grow, and is projected to reach 120 million by 2045. These figures indicate that my country faces enormous challenges in the prevention and control of diabetes.

III. How to screen for diabetes

High-risk groups can be screened through resident health records, basic public health services, and opportunistic screenings (such as during health checkups or when seeking treatment for other diseases). Diabetes screening helps in the early detection of diabetes and improves the prevention and control of diabetes and its complications.

1. Age and frequency of diabetes screening

For adults at high risk of diabetes, early screening is recommended. For children and adolescents at high risk, screening should begin at age 10, but for individuals with early puberty, screening should begin during puberty. Those with normal initial screening results should be screened again at least every 3 years.

2. Methods for diabetes screening

High-risk individuals with at least one risk factor should undergo further screening with fasting blood glucose or random blood glucose. Fasting blood glucose screening is the simplest and most convenient method and should be used as a routine screening method, but there is a possibility of missed diagnoses. If fasting blood glucose is ≥6.1 mmol/L or random blood glucose is ≥7.8 mmol/L, an oral glucose tolerance test (OGTT) is recommended.

IV. Diagnostic Criteria for Diabetes

my country currently adopts the internationally accepted diagnostic criteria proposed by the WHO Expert Committee on Diabetes (1999).

1. Diagnostic criteria for diabetes

Diagnostic criteria for diabetes: Diabetic symptoms plus random blood glucose ≥11.1 mmol/L, or fasting blood glucose ≥7.0 mmol/L, or 2-hour postprandial glucose level (OGTT) ≥11.1 mmol/L. Symptoms of diabetes include polyuria, polydipsia, and unexplained weight loss; random time refers to any time of day, regardless of the time and amount of food consumed at the last meal; fasting refers to the absence of any calorie intake within at least 8 hours.

2. Diagnostic criteria for gestational diabetes mellitus

The 2017 Chinese Guidelines for the Prevention and Treatment of Type 2 Diabetes Mellitus classify pregnancy complicated with hyperglycemia into three categories: (1) gestational diabetes mellitus (GDM), (2) overt gestational diabetes mellitus (ODM), and (3) diabetes mellitus complicated with pregnancy (PGDM).

V. Treatment of Diabetes

In clinical practice, the International Diabetes Federation has proposed five key points for comprehensive diabetes management (commonly known as the "five pillars"), namely diabetes education, medical nutrition therapy, exercise therapy, blood glucose monitoring, and drug therapy.

(I) Diabetes Education

While intervention by healthcare professionals is crucial for successful diabetes management, the key lies in modifying the lifestyles and attitudes of patients and high-risk groups. To achieve this, patient education, one of the "five pillars" of diabetes management, is indispensable.

(II) Medical Nutrition Therapy

1. Calculate total calories: Calculate ideal weight based on age, gender, and height, and calculate the total daily calorie requirement based on lifestyle habits.

2. Nutritional distribution of total calories: 50%–60% carbohydrates, 10%–15% protein, and no more than 30% fat.

(III) Exercise Therapy

Exercise can increase insulin sensitivity, which helps control blood sugar and weight. Exercise intensity is categorized into three levels: appropriate, excessive, and insufficient. The effectiveness of exercise therapy can be evaluated from two aspects: whether exercise goals can be achieved and whether the exercise is safe.

(iv) Blood glucose monitoring

Blood glucose control targets: fasting blood glucose 4.0–7.8 mmol/L, and postprandial blood glucose (2 hours after a meal) 6.0–10.0 mmol/L. Monitoring frequency should be determined based on blood glucose stability. Self-monitoring of blood glucose must be performed according to standardized procedures.

(V) Drug Treatment

Lifestyle intervention is the foundation of diabetes treatment. When diet and exercise cannot achieve target blood glucose control (glycated hemoglobin ≥ 7.0%), drug treatment should be used in a timely manner.