Classification, incidence, and screening of high-risk groups of diabetes

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.

With such a high incidence of diabetes, high-risk groups need to be vigilant.

1. Definition of high-risk groups for diabetes among adults

Adults (>18 years of age) who have any one or more of the following risk factors for diabetes are considered to be at high risk for diabetes.

(1) Age ≥ 40 years old.

(2) History of prediabetes [impaired glucose tolerance (IGT), impaired fasting glucose (IFG) or both].

(3) Overweight (BMI≥24) or obese (BMI≥28) and/or abdominal obesity (waist circumference ≥90cm for men and ≥85cm for women).

(4) A quiet lifestyle.

(5) A family history of type 2 diabetes among first-degree relatives.

(6) Women with a history of gestational diabetes.

(7) Hypertension (systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg), or currently receiving antihypertensive treatment.

(8) Dyslipidemia (high-density lipoprotein cholesterol ≤0.91mmol/L and/or triglycerides ≥2.22mmol/L), or currently undergoing lipid-lowering therapy.

(9) Patients with atherosclerotic cardiovascular disease.

(10) Those with a history of transient steroid-induced diabetes.

(11) Patients with polycystic ovary syndrome (PCOS) or clinical conditions associated with insulin resistance (such as acanthosis nigricans).

(12) Patients who have been receiving long-term treatment with antipsychotic drugs and/or antidepressants and statins.

Among the above categories, people with prediabetes and those with abdominal obesity are the most important high-risk groups for type 2 diabetes. Among them, 6% to 10% of individuals with impaired glucose tolerance will progress to type 2 diabetes each year.

2. Definition of high-risk groups for diabetes among children and adolescents

In children and adolescents (≤18 years old), those who are overweight (BMI > 85th percentile for age and sex) or obese (BMI > 95th percentile for age and sex) and have any of the following risk factors are considered to be at high risk for diabetes.

(1) A family history of type 2 diabetes in a first- or second-degree relative.

(2) The presence of clinical conditions associated with insulin resistance (such as acanthosis nigricans, hypertension, dyslipidemia, polycystic ovary syndrome, and birth weight small for gestational age).

(3) The mother had a history of diabetes or was diagnosed with gestational diabetes during pregnancy.

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.

OGTT is an oral glucose tolerance test that reflects the body's ability to regulate blood glucose levels. OGTT can help detect abnormal glucose metabolism and diagnose diabetes at an early stage.

Patients should make the following preparations before diabetes screening:

(1) Patients can eat normally a few days before the test. If the patient eats very little, the carbohydrate content in the daily diet should not be less than 150g for 3 days before the OGTT, and normal activities should be maintained.

(2) Drugs that affect this trial should be discontinued, such as insulin and adrenocortical hormones.

(3) Patients should not eat for 10 to 14 hours before the test, and fasting blood should be drawn before 8 am on the day of the test.

(4) On the morning of the test, after fasting venous blood collection, the patient drank 300mL of sugar water containing 75g glucose within 5 minutes. Venous blood was drawn 60 minutes, 120 minutes and 180 minutes after drinking the sugar water. Urine was also collected for urine glucose qualitative test.

(5) Before and during the experiment, smoking, drinking alcohol, strong tea and coffee, strenuous exercise, and maintaining emotional stability are prohibited. No one is allowed to leave the premises during the experiment.

(6) No food should be eaten during the experiment, but water intake is not absolutely restricted. When thirsty, you can drink a small amount of plain water (just enough to moisten your throat).

3. How to interpret the results of OGTT?

(1) Normal glucose tolerance. Fasting venous blood glucose <6.1mmol/L, 2-hour OGTT blood glucose <7.8mmol/L, indicating that the body's ability to regulate blood glucose after ingestion is normal.

(2) Diabetes mellitus. Fasting blood glucose ≥7.0 mmol/L or 2-hour postprandial glucose ≥11.1 mmol/L, urine glucose + to ++++, indicating that the body's ability to regulate glucose after eating is significantly reduced.

(3) Impaired glucose tolerance. Fasting venous blood glucose <7.0 mmol/L, and 2-hour OGTT blood glucose between 7.8 and 11.1 mmol/L, indicate a slight decrease in the body's ability to regulate glucose.

(4) Impaired fasting glucose. When fasting venous blood glucose is between 6.1 and 7.0 mmol/L and 2-hour blood glucose in an oral glucose tolerance test (OGTT) is <7.8 mmol/L, it indicates that the body's ability to regulate blood glucose after ingestion is still good, but its ability to regulate fasting blood glucose is slightly reduced.