Fat Hormones, Adipokines

Adipose tissue functions as a dynamic endocrine organ secreting multiple proteins, factors, and hormones into the systemic circulation that are collectively described as adipokines. Adipokines exert pleiotropic effects on target tissues/organs thereby regulating energy homeostasis, metabolism, and insulin sensitivity, as well as immune and cardiovascular functions. Expanding adipose tissue in obesity undergoes a change in the adipokine secretion profile characterized by an increase of proinflammatory adipokines and suppression of anti-inflammatory adipokines increasing proinflammatory pathways within adipose tissue depots and creating an adverse circulating adipokine profile, resulting in a chronic, low-grade, systemic inflammatory state. Compelling evidence directly links the adverse proinflammatory adipokine profile in obesity with a spectrum of detrimental cardio-metabolic effects including hepatic, skeletal muscle, and myocardial insulin resistance, hypertension, atherosclerosis, hypercoagulability, thrombosis, and endothelial and cardiac dysfunction. This chapter presents a brief overview of the nature of adipose tissue in obesity and focuses on selected adipokines that have direct and indirect effects on the heart and cardiovascular system.