Introduction

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by elevated blood glucose levels (hyperglycemia) due to impaired insulin production, insulin action, or both. It is a major global health problem affecting millions of people worldwide and can lead to severe complications if left untreated.

Definition

Diabetes mellitus is a group of metabolic disorders in which the body does not produce enough insulin or cannot effectively use the insulin it produces. This results in long-term high blood sugar levels, which can cause significant damage to various organs over time.

Classification of Diabetes mellitus

• Type 1 diabetes mellitus (T1DM) is caused by autoimmune destruction of the insulin-producing β-cells of the pancreas. Symptoms usually appear in childhood or adolescence, but can occur at any age. These patients require lifelong insulin therapy.
• Type 2 diabetes mellitus (T2DM). This is because insulin resistance causes the β-cells in the pancreas, which secrete insulin, to malfunction. This is most common in adults but is now increasingly seen in younger people. It can be managed with lifestyle changes, oral medications, and sometimes insulin.
• Gestational diabetes (GDM)

Hormonal changes during pregnancy cause insulin resistance. This increases the risk of developing type 2 diabetes after pregnancy. This is why diabetes symptoms appear during that time. In pregnant women, it usually occurs in the second or third trimester.

• Secondary diabetes (due to pancreatic diseases, hormonal disorders, drugs such as steroids, etc.)

Causes and risk factors

• Autoimmune destruction of β-cells (T1DM)
• Insulin resistance and β-cell dysfunction (T2DM)
• Genetic mutations affecting insulin production (monogenic diabetes)
• Pancreatic disorders (chronic pancreatitis, cystic fibrosis)
• Endocrine disorders (Cushing’s syndrome, acromegaly)
• Family history of diabetes
• Obesity (especially central obesity)
• Sedentary lifestyle
• High carbohydrate, high sugar diet
• High blood pressure and dyslipidemia
• Polycystic ovary syndrome (PCOS)
• Ethnicity (high prevalence among South Asians, Africans.)

Diseases Symptoms

• Polyuria – frequent urination
• Polydipsia – excessive thirst
• Polyphagia – increased hunger
• Unexplained weight loss (T1DM)
• Fatigue and weakness
• Blurred vision
• Frequent infections (UTIs, skin infections)
• Slow wound healing
• Tingling/numbness in the hands and feet (neuropathy)

Complications of Diabetes Mellitus (DM)

Diabetes Mellitus (DM) is a chronic metabolic disorder that, if left uncontrolled, can lead to serious complications affecting multiple organs. These complications are classified as short-term and chronic (long-term) complications. Proper management and early intervention can prevent or delay these complications.

Complications of diabetes

1. Diabetic ketoacidosis (DKA)

Symptoms:

• Nausea,
• Vomiting,
• Abdominal pain
• Deep, rapid breathing
• Fruity breath (due to acetone)
• Altered mental status, in severe cases coma

Diagnosis:

• Blood glucose > 250 mg/dL
• Arterial pH < 7.3 (acidosis)
• Ketones in the blood and urine

When blood glucose > 600 mg/dL

• Profound dehydration
• Confusion,
• Drowsiness,
• Coma may occur.

• Hypoglycemia (low blood sugar) is present. This is caused by taking too much insulin, skipping meals, excessive exercise, or drinking alcohol.

Symptoms:

• Sweating,
• Tremors,
• Palpitation
• Confusion,
• Dizziness,
• Coma

Treatment: Immediate action is required at this point and 15 grams of fast-acting glucose (fruit juice, glucose tablets) should be administered.

Chronic complications of diabetes

1. Diabetic retinopathy (eye damage) Damage to the blood vessels in the retina can cause bleeding.
2. There is also a risk of blindness due to abnormal blood vessel growth.
3. Symptoms:
4. Blurred vision
5. Floaters,
6. Dark spots
7. Sudden loss of vision (severe cases)

• Diabetic nephropathy (kidney damage)
• A major factor in chronic kidney disease (CKD).

• Diabetic neuropathy (nerve damage)
• Peripheral neuropathy (most common) – causes numbness, burning pain, and ulcers in the feet. Muscle weakness, pain in the thighs and hips can occur.
• Diabetes accelerates the hardening of the arteries. Therefore, it increases the risk of heart attack and stroke.

Peripheral artery disease (PAD) – poor blood circulation to the legs

• Pain in the legs when walking (claudication).
• Cold, discolored feet.
• Slow-healing and painless ulcers can lead to amputation.

• Increased risk of infection
• High blood sugar weakens the immune system, leading to frequent infections.

Although complications of diabetes can be life-threatening, early detection, lifestyle changes, and proper treatment can prevent severe outcomes. Patient education, regular check-ups, and multidisciplinary management are key to reducing complications.

Diabetes Diagnosis

Blood Tests

• Fasting Plasma Glucose (FBS): ≥ 126 mg/dL (≥ 7.0 mmol/L)

• Random Blood Glucose (RBG): ≥ 200 mg/dL (≥ 11.1 mmol/L) with symptoms

• Oral Glucose Tolerance Test (OGTT): 2-hour post-load glucose ≥ 200 mg/dL

• HbA1c (glycated hemoglobin): ≥ 6.5% (reflects 3-month average blood glucose)

Prediabetes (early stage of diabetes)

• FBS: 100-125 mg/dL (5.6-6.9 mmol/L)

• OGTT: 140-199 mg/dL

• HbA1c: 5.7-6.4%