Insulin resistance – the basics every medical specialist should know

Abstract

Introduction and purpose: Insulin resistance (IR) is a health problem as it can accompany obesity and lead to serious metabolic complications. In recent years, it has been "overdiagnosed" in clinical practice due to the lack of specific diagnostic criteria. The article summarizes the current knowledge in the field of pathophysiology, clinical picture and diagnostics.
 State of knowledge: Obesity remains the leading cause of IR, especially in the 21st century. In a positive energy balance, the adipocyte overloaded with fat protects itself against further influx of glucose and fats and becomes insulin insensitive. A component of IR development is subclinical inflammation of macrophage-rich adipose tissue which is exacerbated by an adipocytokine imbalance, which in turn generates IR. The markers of cellular resistance to insulin are free fatty acids in the bloodstream which are responsible for the lipotoxicity in hepatocytes and myocytes. Compensatory fasting hyperinsulinemia, which is currently considered the most sensitive diagnostic criterion, provides evidence of IR. An effective method of sensitizing cells to insulin is lifestyle modification, including a low-energy diet with regular physical activity in the form of aerobic-resistance exercise. Literature recommends no pharmacological treatment of IR alone, without obesity or other concomitant diseases.
 Conclusions: IR is not a separate disease, but only a pathological expression of cells' adaptation to excess of consumed energy. However, in its systemic form, when the protective mechanisms become ineffective, it induces metabolic disturbances. Only the causal treatment of IR guarantees therapeutic success.