Type 2 diabetes

Type 2 diabetes
Name	Type 2 diabetes
Synonyms	Non-insulin-dependent diabetes, adult-onset diabetes
Caption	Blood glucose monitoring is a key part of management.
Field	Endocrinology
Symptoms	Increased thirst, frequent urination, unexplained weight loss
Complications	Cardiovascular disease, Diabetic retinopathy, Chronic kidney disease
Onset	Typically middle or older age
Duration	Long-term
Causes	Obesity, lack of physical activity, genetics
Risks	Family history, hypertension, dyslipidemia
Diagnosis	Blood tests such as HbA1c, Fasting plasma glucose
Differential	Type 1 diabetes, Monogenic diabetes
Prevention	Healthy diet, exercise, maintaining a normal body weight
Treatment	Lifestyle modification, Metformin, Insulin
Medication	Sulfonylurea, GLP-1 receptor agonist, SGLT2 inhibitor
Prognosis	Variable with management
Frequency	~463 million (2019)
Deaths	~4.2 million per year

Type 2 diabetes. It is a chronic metabolic disorder characterized by high blood sugar levels due to insulin resistance and relative insulin deficiency. The condition represents a major global health challenge and is associated with significant morbidity and mortality. Effective management requires a multifaceted approach involving lifestyle changes and often pharmacological intervention.

Signs and symptoms

Classic symptoms include polyuria, polydipsia, and unexplained weight loss. Many individuals may be asymptomatic for years, with the condition detected only through routine blood tests. Other common presentations include fatigue, blurred vision, and slow-healing wounds. The presence of acanthosis nigricans can be a cutaneous marker. Complications such as peripheral neuropathy may manifest as paresthesia or pain in the extremities.

Causes and risk factors

The development is strongly linked to modifiable risk factors, primarily obesity and physical inactivity. Genetic predisposition plays a significant role, with a higher prevalence among those with a family history. Specific ethnic groups, including African Americans, Hispanic and Latino Americans, and South Asians, are at increased risk. Other contributing factors include advanced age, a history of gestational diabetes, and conditions like polycystic ovary syndrome. Environmental factors and urbanization also contribute to its rising incidence.

Pathophysiology

The core defect involves insulin resistance, where tissues such as skeletal muscle, liver, and adipose tissue fail to respond normally to insulin. This is often accompanied by a progressive decline in beta-cell function within the pancreatic islets, leading to inadequate insulin secretion. The liver contributes to hyperglycemia through excessive gluconeogenesis. Dysfunctional adipokine secretion from adipose tissue, such as increased resistin and decreased adiponectin, further exacerbates metabolic dysfunction.

Diagnosis

Diagnosis is established using criteria set by organizations like the American Diabetes Association or the World Health Organization. Key diagnostic tests include measurement of HbA1c, Fasting plasma glucose, and the Oral glucose tolerance test. A random plasma glucose level above a certain threshold in a symptomatic person can also confirm the diagnosis. Differential diagnosis from Type 1 diabetes may involve testing for autoantibodies such as Glutamic acid decarboxylase antibodies.

Management

First-line therapy involves intensive lifestyle modification, including medical nutrition therapy and increased physical activity. The medication Metformin is typically the initial pharmacological agent. If glycemic targets are not met, additional agents like Sulfonylureas, DPP-4 inhibitors, GLP-1 receptor agonists, or SGLT2 inhibitors are added. Insulin therapy, including basal insulin or prandial insulin, may be required in advanced cases. Management also focuses on controlling blood pressure and LDL cholesterol to prevent complications.

Epidemiology

It is a leading cause of morbidity worldwide, with prevalence rising dramatically. According to the International Diabetes Federation, approximately 463 million adults were affected in 2019. High rates are observed in Pacific Island nations and the Middle East and North Africa region. The increase is closely tied to global trends in obesity and sedentary lifestyles. It represents a substantial economic burden on healthcare systems, including those of the National Health Service in the United Kingdom and Medicare in the United States.

History

Descriptions of conditions resembling it appear in ancient medical texts from Egypt and India. The term "diabetes" was used by the Greek physician Aretaeus of Cappadocia. A pivotal moment was the discovery of insulin by Frederick Banting and Charles Best in the 1920s, though this was more critical for Type 1 diabetes. The distinction between type 1 and type 2 was clarified in the 20th century. Major clinical trials like the United Kingdom Prospective Diabetes Study and the Diabetes Control and Complications Trial have fundamentally shaped modern management strategies.

Category:Diabetes Category:Endocrine diseases Category:Metabolic disorders