The delicate balance between fat and muscle: adipokines in metabolic disease and musculoskeletal inflammation.

Adipose tissue has evolved as a complex organ with functions far beyond the mere storage of energy. Chronic oversupply of calories, common to Western-style diets, frequently goes hand-in-hand with an altered secretion pattern of adipokines and elevated plasma free fatty acid levels, known to modulate insulin sensitivity in skeletal muscle. Intramyocellular accumulation of lipids directly attenuates insulin signaling within myocytes via distinct kinases. Obesity is also accompanied by an enhanced basal inflammatory tone, originating from adipocytes and adipose tissue-associated macrophages. In addition, adipocytes accumulate within the skeletal muscle and exert direct paracrine effects on muscle insulin sensitivity.