Primary and secondary insulin resistance.

Insulin resistance (IR) is defined as insufficient insulin metabolic effect in target tissues, including glucose utilisation in skeletal muscle, suppression of hepatic glucose production and suppression of lipolysis in fat tissue. Primary IR originates as consequence of rare monogenetic defects of insulin receptor or molecules includes to post-receptor insulin signal cascade. Secondary IR originates mainly as a result of metabolic or hormonal changes, most commonly in visceral obesity by multifactorial postreceptor inhibition of insulin signal and it is associated with metabolic syndrome and type 2 diabetes mellitus. It is also present in endocrinopathies with overproduction of contraregulatory insulin hormones (cortisol, growth hormone, catecholamines) and using of some drugs (mainly steroids, immunosuppressive treatment). In practice IR is usually diagnosed by glycemic parameters with confirmation of prediabetic states and type 2 diabetes mellitus. The healthy life style and physical activity associated with weight loss are the most important for type 2 diabetes prevention. According to actual international guidelines metformin is only antidiabetic drug which is possible to use in prediabetic states with high risk of type 2 diabetes development, mainly in obese subjects with BMI > 35 kg/m2, age under 60 years and in women with history of gestational diabetes.