Type 2 diabetes subtypes, aetiology and pathophysiology

Type 2 Diabetes Mellitus (T2DM) is a heterogeneous metabolic disorder characterized by chronic hyperglycemia resulting from a combination of progressive pancreatic beta-cell dysfunction and peripheral insulin resistance. Aetiology & Risk Factors The disease arises from a complex interaction between genetic susceptibility and environmental triggers, including physical inactivity, visceral obesity, poor diet, and aging. Pathophysiology Insulin resistance in muscle, liver, and adipose tissue impairs glucose uptake and suppresses hepatic glucose production. To compensate, pancreatic beta-cells overproduce insulin until progressive beta-cell exhaustion leads to severe insulin deficiency and sustained hyperglycemia. Subtypes (Novel Precision Clusters) Modern classification identifies distinct biological subtypes: Severe Insulin-Deficient Diabetes (SIDD): Marked by early beta-cell failure and high HbA1c. Severe Insulin-Resistant Diabetes (SIRD): Linked to high BMI, severe tissue insulin resistance, and elevated kidney disease risk. Mild Obesity-Related Diabetes (MOD): Associated with early-onset obesity. Mild Age-Related Diabetes (MARD): Occurs in older populations with a milder disease progression. Type 2 Diabetes Mellitus (T2DM) is a heterogeneous metabolic disorder characterized by chronic hyperglycemia resulting from a combination of progressive pancreatic beta-cell dysfunction and peripheral insulin resistance. Aetiology & Risk Factors The disease arises from a complex interaction between genetic susceptibility and environmental triggers, including physical inactivity, visceral obesity, poor diet, and aging. Pathophysiology Insulin resistance in muscle, liver, and adipose tissue impairs glucose uptake and suppresses hepatic glucose production. To compensate, pancreatic beta-cells overproduce insulin until progressive beta-cell exhaustion leads to severe insulin deficiency and sustained hyperglycemia. Subtypes (Novel Precision Clusters) Modern classification identifies distinct biological subtypes: Severe Insulin-Deficient Diabetes (SIDD): Marked by early beta-cell failure and high HbA1c. Severe Insulin-Resistant Diabetes (SIRD): Linked to high BMI, severe tissue insulin resistance, and elevated kidney disease risk. Mild Obesity-Related Diabetes (MOD): Associated with early-onset obesity. Mild Age-Related Diabetes (MARD): Occurs in older populations with a milder disease progression.