CD4 and metabolic disease: This inflammation is called metabolic inflammation and is similar to the chronic inflammatory process that occurs during aging.247 Increased fat mass, metabolic dysfunction, and systemic inflammatory responses are key features of these metabolic diseases and can further exacerbate immune dysfunction associated with aging.164 In T2D, a hallmark of immune aging is a reduction in the proportion of naïve CD4+ T cells alongside increased memory CD4+ T cells and effector CD4+ and CD8+ T cells.