> “A fat cell is almost like a primitive immune cell,” says Hotamisligil. “It can request the assistance of immune cells when in trouble, but if the stress continues, and the immune cells remain, they start changing their character and behavior from helpful to harmful.”
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> When overloaded with stored lipid, fat cells begin to lose their functional and structural integrity and may start spilling their toxic cargo. When cells fail like this, the immune system kicks in, initially to assist in clean-up. Macrophages engorge themselves on the leaking fuel, and may die themselves during this process. But in the long run, what is meant to be a mutually beneficial interaction between the metabolic and immune systems turns into a very dangerous and harmful relationship. Obese individuals thus live in a state of chronic stress and inflammation; in fact, many people do, because their energy intake vastly exceeds their needs. Hotamisligil calls this chronic energy overload, and the resulting abnormal immune response, metaflammation: metabolic inflammation.
This article brings together a whole host of different areas of research about human inflammation. I would recommend reading it, but it isn't an article you can skim and there's no big bang conclusions, just more areas of keen research and exploration.