When insomnia symptoms persist for a period of time, the inflammatory response in the body is aggravated, resulting in the release of more inflammatory factors, among which C-reactive protein (CRP), IL-1, IL-6 and tumor necrosis factor α (TNF-α) lead to vascular endothelial cell dysfunction and endothelium-dependent vasodilation function is reduced. Here, IL6 is linked to insomnia.