- Type 2 diabetes mellitus, commonly known as Type 2 diabetes, is a chronic metabolic disorder characterized by insulin resistance and relative insulin deficiency, leading to elevated blood glucose levels, or hyperglycemia. It is the most common form of diabetes, accounting for over 90% of all diabetes cases globally.
- Unlike type 1 diabetes, which involves autoimmune destruction of insulin-producing beta cells in the pancreas, type 2 diabetes typically develops over time and is closely linked to lifestyle factors such as poor diet, physical inactivity, obesity, and genetic predisposition.
- The pathophysiology of type 2 diabetes involves a complex interplay between insulin resistance—where body tissues such as muscle, liver, and fat become less responsive to insulin—and a progressive decline in pancreatic beta-cell function. Initially, the pancreas compensates for insulin resistance by producing more insulin, but over time, this compensation fails, leading to persistent hyperglycemia. The chronic high glucose levels disrupt normal cellular processes, damage blood vessels, and contribute to long-term complications.
- Clinical symptoms of type 2 diabetes may develop gradually and can be subtle or absent for years. Common signs include frequent urination (polyuria), excessive thirst (polydipsia), increased hunger (polyphagia), fatigue, blurred vision, and slow wound healing. Because of its insidious onset, many individuals are diagnosed only after complications have developed.
- Diagnosis is made through blood tests such as fasting plasma glucose (FPG), oral glucose tolerance test (OGTT), and hemoglobin A1c (HbA1c), which measures average blood glucose levels over the past two to three months. An HbA1c level of 6.5% or higher, a fasting glucose of 126 mg/dL (7.0 mmol/L) or more, or a 2-hour OGTT result over 200 mg/dL (11.1 mmol/L) typically confirms the diagnosis.
- Management of type 2 diabetes focuses on glycemic control, cardiovascular risk reduction, and lifestyle modification. A cornerstone of treatment is dietary changes, emphasizing balanced meals, reduced sugar and refined carbohydrate intake, and portion control. Regular physical activity, such as brisk walking or aerobic exercise, improves insulin sensitivity and helps with weight control. Pharmacological interventions include oral antidiabetic agents like metformin, sulfonylureas, DPP-4 inhibitors, SGLT2 inhibitors, and GLP-1 receptor agonists, and in some cases, insulin therapy is required. The choice of therapy depends on the individual’s metabolic profile, comorbidities, and risk of hypoglycemia.
- Long-term complications of poorly controlled type 2 diabetes include macrovascular complications—such as coronary artery disease, stroke, and peripheral artery disease—and microvascular complications, including retinopathy, nephropathy, and neuropathy. The condition also increases susceptibility to infections and may impair wound healing, contributing to risks such as diabetic foot ulcers and amputation.
- Preventive strategies are critical in combating the growing global burden of type 2 diabetes. Interventions targeting high-risk individuals, such as those with prediabetes, through lifestyle coaching, weight loss, and regular screening, have proven effective in delaying or preventing disease onset. Public health efforts that promote healthier eating habits, physical activity, and obesity prevention are essential in addressing the epidemic at a population level.
