The inflammatory process of adipose tissue

Obesity and inflammation are highly integrated processes in the pathogenesis of insulin resistance, diabetes, atherosclerosis, and non-alcoholic fatty liver disease. The evidence that obesity can be regarded as an inflammatory disease comes from numerous studies showing a moderate increase of circulating inflammatory factors in obese patients and the identification of different types of immune cells infiltrating the human adipose tissue. Obesity may induce a pro-inflammatory state, which can cause or worsen insulin resistance in adipose tissue, skeletal muscle, and liver. The causative factors of this inflammation process in obesity are not entirely understood, but adipose tissue seems to play an important role in the relationship between obesity and chronic inflammation. Increased infiltration of adipose tissue with immune cells could cause adipose tissue insulin resistance via autocrine and paracrine cytokine/adipokine signalling, which contributes to systemically decreased insulin sensitivity via endocrine signalling. On the other hand, obesity-induced inflammation could represent a compensatory mechanism for increased adipose tissue turnover in obese states, which might protect obese individuals against deleterious effects of fat accumulation. A better understanding of the mechanisms and molecular components of obesity induced inflammatory response might lead to identifying novel therapeutic targets to prevent obesity-related complications.