Adipose Tissue

Adipose Tissue

Adipose tissue is the body’s main energy store. It holds calories as triglycerides inside specialized cells called adipocytes. It is also a major endocrine organ that releases many active molecules, known together as adipokines. These include leptin, adiponectin, resistin and inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6). Through these signals, fat tissue helps regulate energy balance, glucose metabolism, lipid levels and inflammation throughout the body.

Humans have two main types: white adipose tissue (WAT) and brown adipose tissue (BAT). White fat is the main form in adults and mostly stores energy and releases adipokines. Brown fat burns energy to make heat, using uncoupling protein 1 (UCP1). A third type, beige or “brite” fat cells, can appear inside white fat after cold exposure or certain drugs and also produce heat, much like brown fat. The balance between storing energy in white fat and burning it in brown and beige fat is a major focus of obesity research.

Clinical Relevance to Retatrutide

Too much fat tissue, especially visceral fat around the abdominal organs, is a hallmark of obesity and is strongly linked to insulin resistance, type 2 diabetes and cardiovascular disease. Retatrutide, a triple agonist of the GLP-1, GIP and glucagon receptors, has produced large drops in body weight in clinical trials, much of it from lost fat. Its glucagon receptor activity is thought to speed fat breakdown (lipolysis) and raise energy use, which may add to the fat loss from GLP-1 receptor activity alone. Less visceral fat and less fat stored in organs such as the liver may explain many of the metabolic gains seen with retatrutide, including better insulin sensitivity and less fatty liver.