Diabetes Mellitus

Introduction

Diabetes Mellitus (DM) is a chronic metabolic disorder characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both. It is a major global health concern, affecting millions of people worldwide. If left unmanaged, diabetes can lead to severe complications such as cardiovascular disease, kidney failure, neuropathy, and retinopathy.

Types of Diabetes Mellitus

There are three main types of diabetes mellitus:

1. Type 1 Diabetes Mellitus (T1DM): An autoimmune condition where the immune system attacks insulin-producing beta cells in the pancreas, leading to an absolute insulin deficiency. It is often diagnosed in childhood or adolescence and requires lifelong insulin therapy.
2. Type 2 Diabetes Mellitus (T2DM): The most common form of diabetes, characterized by insulin resistance and relative insulin deficiency. It is closely linked to obesity, sedentary lifestyle, and genetic predisposition.
3. Gestational Diabetes Mellitus (GDM): A temporary condition that occurs during pregnancy when the body cannot produce enough insulin to meet the increased demands. While it usually resolves postpartum, it increases the risk of developing Type 2 diabetes later in life.

Causes and Risk Factors

Diabetes mellitus is influenced by genetic, environmental, and lifestyle factors. The key risk factors include:

• Genetic predisposition: Family history of diabetes increases susceptibility.
• Obesity: Excess fat, particularly visceral fat, contributes to insulin resistance.
• Sedentary lifestyle: Lack of physical activity reduces insulin sensitivity.
• Unhealthy diet: High intake of processed foods, sugary beverages, and refined carbohydrates.
• Age: Risk increases with age, particularly in Type 2 diabetes.
• Ethnicity: Certain ethnic groups, such as African American, Hispanic, and South Asian populations, have a higher prevalence.
• Hypertension and dyslipidemia: Coexisting conditions that contribute to metabolic syndrome.

Pathophysiology

In diabetes mellitus, glucose metabolism is disrupted due to insufficient insulin production or ineffective insulin action. This leads to elevated blood glucose levels (hyperglycemia), which over time, cause damage to various organs and tissues.

• Type 1 DM: Autoimmune destruction of pancreatic beta cells results in absolute insulin deficiency, leading to increased blood glucose and ketone production.
• Type 2 DM: Insulin resistance in muscle, liver, and fat cells causes impaired glucose uptake, leading to chronic hyperglycemia.
• Gestational DM: Hormonal changes during pregnancy cause temporary insulin resistance, increasing blood glucose levels.

Symptoms of Diabetes Mellitus

Common symptoms of diabetes include:

• Polyuria (frequent urination)
• Polydipsia (excessive thirst)
• Polyphagia (increased hunger)
• Unexplained weight loss (more common in Type 1)
• Fatigue
• Blurred vision
• Slow-healing wounds
• Recurrent infections

Diagnosis

The following tests are used to diagnose diabetes:

1. Fasting Plasma Glucose (FPG): Measures blood glucose after an 8-hour fast. A level ≥126 mg/dL indicates diabetes.
2. Oral Glucose Tolerance Test (OGTT): Measures blood glucose 2 hours after ingesting a glucose solution. A level ≥200 mg/dL suggests diabetes.
3. Glycated Hemoglobin (HbA1c): Reflects average blood glucose levels over 2-3 months. A value ≥6.5% is diagnostic for diabetes.
4. Random Plasma Glucose Test: A random blood glucose level ≥200 mg/dL with symptoms confirms diabetes.

Treatment and Management

Lifestyle Modifications

• Dietary Changes: Emphasizing whole grains, lean proteins, healthy fats, and fiber-rich foods while limiting sugar and processed foods.
• Physical Activity: Regular exercise (at least 150 minutes per week) improves insulin sensitivity.
• Weight Management: Maintaining a healthy BMI reduces the risk of complications.

Medications

• Insulin Therapy: Essential for Type 1 diabetes and sometimes required in Type 2 and gestational diabetes.
• Oral Hypoglycemic Agents:
  • Metformin: First-line treatment for Type 2 diabetes, reduces liver glucose production.
  • Sulfonylureas: Stimulate insulin secretion from pancreatic beta cells.
  • SGLT2 Inhibitors: Promote glucose excretion through urine.
  • DPP-4 Inhibitors: Enhance incretin hormone function to lower blood glucose.
  • GLP-1 Receptor Agonists: Improve insulin secretion and delay gastric emptying.

Monitoring Blood Glucose

Regular monitoring is essential for managing diabetes effectively. Patients should check their blood glucose levels using a glucometer and aim for target ranges as recommended by their healthcare provider.

Complications of Diabetes

Long-term complications include:

• Cardiovascular Disease: Increased risk of heart attacks and strokes.
• Neuropathy: Nerve damage causing pain, tingling, and numbness, especially in the feet.
• Nephropathy: Kidney damage leading to chronic kidney disease or failure.
• Retinopathy: Vision impairment or blindness due to damage to retinal blood vessels.
• Diabetic Foot: Poor circulation and nerve damage increase the risk of infections and ulcers.

Prevention Strategies

Preventing diabetes involves:

• Maintaining a healthy diet and active lifestyle.
• Regular medical check-ups for early detection of prediabetes.
• Avoiding smoking and excessive alcohol consumption.
• Managing stress through mindfulness and relaxation techniques.

References

1. American Diabetes Association. (2024). Standards of Medical Care in Diabetes. Diabetes Care.
2. World Health Organization. (2023). Global Report on Diabetes. WHO Publications.
3. National Institute of Diabetes and Digestive and Kidney Diseases. (2024). Diabetes Overview. NIH.
4. Mayo Clinic. (2023). Diabetes Symptoms and Causes. Mayo Clinic Website.
5. Centers for Disease Control and Prevention. (2024). Diabetes Basics. CDC.gov.

This document provides a comprehensive overview of diabetes mellitus, covering its types, causes, symptoms, diagnosis, treatment, complications, and prevention.