10 essential facts for a correct understanding of diabetes

Prof. Dr. Thai Hong Quang

Former Director of Military Hospital 103 – Former President of the Vietnam Association of Diabetes and Endocrinology

 

1. WHAT IS DIABETES MELLITUS?

• Diabetes mellitus (DM) is a chronic disease involving multiple factors in its pathogenesis. Beyond glycemic control, it requires continuous medical care through various measures to reduce risk factors. Regular education and support for patients to perform self-care are vital to prevent acute complications and reduce the risk of chronic complications. Treatment strategies must be multifaceted, focusing on blood glucose control while simultaneously treating diabetes-related complications and acute or chronic comorbidities, depending on each patient to establish a treatment plan (individualized treatment).
• Diabetes occurs when blood glucose (sugar) levels are high due to any cause that makes pancreatic beta cells fail to secrete insulin, secrete insufficient insulin, or when the body does not respond adequately to the effects of insulin. Sugar is not metabolized and cannot enter cells, remaining in the blood and causing hyperglycemia. Continuous high blood sugar over a long period is the cause of many dangerous complications such as cardiovascular disease, kidney disease, neurological disease, blindness, limb amputation, etc., reduced quality of life, and mortality.
• Glucose primarily comes from starch (carbohydrates) in food and drinks, serving as the energy source for the body. Through circulation, glucose is delivered to the cells to ensure the body’s vital activities.
• The disease occurs at any age and is a chronic condition that requires lifelong medication and lifestyle changes (physical exercise and nutrition).

2. WHAT ARE THE TYPES OF DIABETES?

Most common types of diabetes:

2.1. Type 2 Diabetes. Caused by the body not secreting enough insulin or cells responding abnormally to insulin (insulin resistance). This is the most common form (over 90% of people with diabetes), primarily seen in adults but can also occur in children.

2.2. Prediabetes. This is an early stage of diabetes where blood glucose levels are higher than normal but not yet high enough to be diagnosed as Type 2 diabetes. If detected early, measures such as nutrition and physical exercise can prevent it from progressing to Type 2 diabetes.

2.3. Type 1 Diabetes. An autoimmune disease where the body’s immune system attacks and destroys its own insulin-secreting cells in the pancreas. Type 1 accounts for nearly 10% of people with diabetes. It mainly occurs in young and middle-aged people but can appear at any age.

2.4. Gestational Diabetes. Occurs during pregnancy and usually resolves after delivery. However, if a woman had gestational diabetes in a previous pregnancy, she has a higher risk of developing Type 2 diabetes in the future.

2.5 Specific Types of Diabetes due to other causes such as: Monogenic diabetes syndromes (e.g., neonatal diabetes, MODY), diabetes resulting from diseases of the exocrine pancreas (e.g., cystic fibrosis), or induced by drugs or chemicals (such as glucocorticoid treatment, HIV/AIDS treatment, or following organ transplantation).

3. IS DIABETES COMMON?

According to several large-scale studies worldwide, in 2025, approximately 537 million adults globally have diabetes; this figure is projected to rise to 643 million by 2030 and 783 million by 2045. 37.3 million (11%) of the U.S. population have diabetes, with Type 2 being the most common form (90-95%).

In our country, national surveys by the National Hospital of Endocrinology show: In 2002, the prevalence of diabetes nationwide was 2.7%. After 10 years, in 2012, this rate doubled to 5.4%. The most recent national survey (2020) found the diabetes prevalence in Vietnam to be 7.3%; the prediabetes rate was 17.8%. Over 60% of people with diabetes remain undiagnosed, and more than half of adults have never had a blood glucose test to screen for diabetes.

According to the International Diabetes Federation (IDF, 2025), in Vietnam, among people aged 20 to 79, there were 2.5 million people living with diabetes in 2024.

4. WHAT ARE THE CAUSES OF DIABETES?

It depends on the type of diabetes. For example:

• Insulin Resistance. This is the primary cause of Type 2 diabetes. It occurs when organs and tissues such as muscle, fat, and liver do not respond adequately to insulin. Factors contributing to insulin resistance include obesity, being overweight, physical inactivity, poor diet, hormonal imbalance, genetics, and certain medications.
• Autoimmune Disease. Type 1 diabetes or LADA occurs when the immune system attacks the body’s own insulin-producing cells in the pancreas.
• Hormonal Imbalance. During pregnancy, the placenta releases hormones that cause insulin resistance. Gestational diabetes occurs when the pancreas cannot produce enough insulin to overcome this resistance. Other endocrine disorders like acromegaly and Cushing’s syndrome can also cause Type 2 diabetes.
• Physical damage, trauma, or pancreatic surgery.
• Genetic mutations, which cause MODY and neonatal diabetes.
• Long-term use of certain drugs such as HIV/AIDS medications and glucocorticoids.

 

5. SYMPTOMS OF DIABETES

Symptoms depend on the type of diabetes but generally include:

• Increased thirst (polydipsia), frequent urination (polyuria), dry mouth, fatigue, blurred vision, unexplained weight loss, slow-healing skin sores, or infections/fungal issues in the genital area, etc. If these symptoms occur, consult a doctor immediately.
• Symptoms by type:

+ Type 1 Diabetes: Can develop very quickly over weeks or months. If undetected, it can lead to hyperglycemia-induced coma and death without timely emergency care. Recognizing symptoms: excessive urination, excessive thirst, nausea, weight loss, vomiting, stomach pain, fruity-smelling breath, difficulty breathing…

+ Type 2 Diabetes and Prediabetes: Patients may have no symptoms and may not know they have diabetes. It is often discovered incidentally during routine check-ups. Non-specific symptoms include fatigue, weakness, weight fluctuations, or dark patches of skin (acanthosis nigricans) on the back of the neck.

+ Gestational Diabetes: Usually has no clear symptoms. Women with a history of gestational diabetes, those who gave birth to a baby ≥ 4kg, or those with Polycystic Ovary Syndrome (PCOS) should visit endocrinology and obstetrics specialists for an oral glucose tolerance test (OGTT).

6. COMPLICATIONS OF DIABETES.

Diabetes can cause acute complications (rapid and severe) and chronic complications that persist throughout the disease, primarily due to continuously high blood sugar levels over time.

+ Acute Complications. Dangerous and potentially fatal without emergency intervention. There are 3 common types:

• Type 2 Diabetes often presents with Hyperosmolar Hyperglycemic State (HHS), occurring when blood glucose exceeds 33.3 mmol/L (600 mg/dL) for a long period, causing severe dehydration and coma.
• Type 1 Diabetes often presents with Diabetic Ketoacidosis (DKA). Since the body lacks insulin, glucose cannot be metabolized for energy; the body breaks down fat instead, releasing ketones. This leads to acidosis, characterized by fruity breath, vomiting, and eventually coma.
• Hypoglycemic Coma. A dangerous emergency, especially in patients on insulin or certain medications, due to incorrect dosing, skipping meals, or excessive physical activity. Blood glucose drops significantly (venous glucose < 3 mmol/L), depriving the brain of energy. Patients may experience seizures or increased muscle tone, leading to deep coma. Immediate treatment involves consuming sugar water or receiving intravenous hypertonic glucose/glucagon injection to avoid irreversible brain damage or death.

+ Chronic Complications.

• Cardiovascular complications. The most common chronic complication, including: coronary artery disease, heart attack (myocardial infarction), stroke, and atherosclerosis.
• Other complications: Neuropathy (numbness, tinnitus, etc.), Nephropathy leading to kidney failure, Retinopathy which can lead to blindness, diabetic foot ulcers which may require amputation, infections, slow-healing wounds, erectile dysfunction, and gastroparesis. Depression (the rate of depression in people with diabetes is 2 to 3 times higher than in those without).

7. DIAGNOSING DIABETES

The following table presents the diagnostic criteria for diabetes and prediabetes.

	Prediabetes	Diabetes
HbA1c	5.7 – 6.4%	≥ 6.5%
Fasting Plasma Glucose	5.6 – 6.9 mmol/L (100 – 125 mg/dL)	≥ 7.0 mmol/L ( ≥ 126 mg/dL)
Oral Glucose Tolerance Test (2h post-load)	7.8 – 11.0 mmol/L (140 – 199 mg/dL)	≥ 11.1 mmol/L ( ≥ 200 mg/dL)
Random blood test + symptoms of hyperglycemia or acute hyperglycemic crisis.		≥ 11.1 mmol/L (≥ 200mg/dL)

 

Note:

• Annual health check-ups are recommended for early detection of prediabetes and diabetes.
• Once diagnosed, annual exams (or more frequent) are necessary to detect complications early for timely treatment.

8. TREATMENT OF DIABETES.

Diabetes has a complex pathogenesis; therefore, treatment strategies must be diverse, combining glycemic control with the treatment of complications and comorbidities. As a chronic disease requiring lifelong care, adherence to treatment and following medical instructions are decisive for success.

• Diet and Nutrition: A suitable meal plan and regular physical activity (at least 30 minutes daily) are vital regardless of the type of diabetes.
• Blood Glucose Monitoring: Essential for tracking the disease and adjusting medication dosages.
• Oral Hypoglycemic Agents: For patients whose pancreas can still secrete insulin (primarily Type 2, prediabetes, and some gestational cases).
• Insulin: A hormone secreted by pancreatic beta cells that metabolizes sugar. Synthetic insulin is the fundamental treatment for Type 1 and some Type 2 patients. Various types exist: rapid-acting, intermediate, long, and ultra-long acting. Delivery methods include vials, pens, or inhaled forms. Only use as prescribed. The most dangerous side effect is hypoglycemia.
• To prevent cardiovascular complications, one must manage blood pressure, weight, and lipid disorders (cholesterol).
• Modern treatments have advanced significantly, combining traditional drugs with SGLT inhibitors (Sodium-glucose cotransporter inhibitors), GLP-1RA (glucagon-like peptide 1 Receptor agonists), and regenerative medicine (using mesenchymal stem cells), which have improved outcomes and longevity.

 

9. PROGNOSIS.

Prognosis depends on the following factors:

• Type of diabetes
• Duration of the disease
• Treatment adherence
• Comorbidities (other accompanying diseases)
• The presence and duration of complications.

Note: Prolonged high blood sugar is the main cause of severe irreversible complications and reduced life expectancy. Diabetes is a leading cause of death, often due to heart attack or stroke. Prognosis improves with lifestyle management, regular exercise, proper diet, and routine monitoring. Maintaining HbA1c ≤ 7% significantly reduces complication risks.

 

10. PREVENTING DIABETES.

While preventing autoimmune or genetic types remains difficult, the following measures can reduce the risk of developing prediabetes and Type 2 diabetes:

• Screening for early detection of prediabetes, diabetes, and complications.
• A healthy, balanced diet.
• Regular physical activity (at least 30 minutes daily, 5 days a week).
• Maintaining a healthy BMI.
• Avoiding unnecessary stress.
• Limiting (preferably avoiding) alcohol.
• Getting enough sleep (7 to 9 hours) and addressing sleep disorders.
• Not smoking or quitting if you currently smoke.
• Managing existing cardiovascular risk factors./.

REFERENCES

1. Thai Hong Quang. Clinical Practice in Diabetes. Medical Publishing House. 2012.

2. Vietnam Association of Diabetes and Endocrinology. Recommendations on Diagnosis and Treatment of Diabetes. Medical Publishing House. 2018.

3. IDF Diabetes Atlas 11^th edition 2025.

4. American Diabetes Association Standards of Medical Care in Diabetes 2026.

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