Another cytokine called IL-10 mediates the expression of increased ferritin receptors on the surface of macrophages, which then sequesters even more iron.
Iron studies show low serum iron levels, normal to low serum iron transferrin or total iron binding capacity, low transferrin saturation, and normal or increased serum ferritin levels.
Two studies, one looking at a Japanese population and a Mexican population found that the body's storage form of iron, ferritin, correlated with visceral fat and insulin resistance — two hallmarks of the metabolic syndrome.