Adipokiner

Adipokiner, or adipocytokines, are a diverse group of signaling proteins secreted mainly by adipose tissue. They function as hormones and cytokines that coordinate metabolic and inflammatory processes across organs. They are produced by adipocytes and cells of the adipose tissue stroma, including macrophages, and can act autocrine, paracrine, or endocrine.

In metabolism they influence appetite and energy expenditure (notably leptin) and modulate insulin sensitivity and lipid metabolism in liver and muscle (adiponectin, resistin, visfatin). Inflammation is another key dimension; adipose tissue releases pro-inflammatory cytokines such as TNF-alpha and IL-6, particularly in obesity, contributing to chronic low-grade inflammation and insulin resistance.

Prominent adipokines include adiponectin (anti-inflammatory and insulin-sensitizing; reduced in obesity) and leptin (satiety signaling; often elevated in obesity with possible leptin resistance). Pro-inflammatory mediators such as TNF-alpha and IL-6 are linked to insulin resistance. Resistin and visfatin have complex roles in glucose metabolism and inflammatory signaling.

Clinical relevance: Altered adipokine profiles are associated with obesity-related diseases, including type 2 diabetes, cardiovascular disease, and NAFLD. Because adipokine signaling links metabolism and inflammation, it is a focus of research for therapies aiming to improve insulin sensitivity and reduce metabolic risk.

See also: adipose tissue, cytokines, inflammation, metabolic syndrome.