adipokinen

Adipokines are a group of bioactive molecules secreted by adipose tissue. They include hormones and cytokines produced by adipocytes and other cells in fat tissue, reflecting an endocrine function of adipose tissue. Classic adipokines include adiponectin, leptin, resistin, and visfatin (NAMPT), along with chemerin, omentin, and apelin. These factors circulate in the blood and can act at distant organs, though some also function locally within adipose tissue.

Adipokines regulate energy balance, glucose and lipid metabolism, appetite, and insulin sensitivity, as well as inflammatory and immune processes. Adiponectin generally improves insulin sensitivity and has anti-inflammatory effects, whereas leptin controls appetite and energy expenditure but obesity is associated with leptin resistance. Pro-inflammatory adipokines such as TNF-α, IL-6, and resistin tend to be elevated in obesity, contributing to chronic low-grade inflammation and metabolic dysfunction.

Secreted by adipocytes and stromal vascular cells, adipokines signal through specific receptors and participate in autocrine, paracrine, and endocrine communication. They influence liver, muscle, brain, vasculature, and immune cells, linking adipose tissue function to systemic metabolism and inflammation.

Altered adipokine profiles are associated with metabolic diseases including type 2 diabetes, obesity, metabolic syndrome, and cardiovascular disease. Therapeutic approaches aim to modulate adipokine signaling or increase beneficial adipokines, but clinical translation remains complex. The recognition of adipose tissue as an endocrine organ emerged in the late 20th century and has shaped current understanding of obesity-related disease.

See also adipose tissue, cytokines, metabolic syndrome.