IL6 and endothelial dysfunction: Several population studies have shown associations between frailty status and markers of inflammation (C-reactive protein (CRP) and interleukin-6 (IL-6)), markers of coagulation activation (D-dimer, factor VIII [8] and fibrinogen [6]) and biomarkers of endothelial dysfunction, such as asymmetric dimethylarginine, and flow mediated dilation, an ultrasound parameter that reflects endothelial function [11, 12].