Past-month insomnia symptoms were assessed by the item, “Difficulty falling or staying asleep?,” with the following response options: “I do not have this symptom” or “I have this symptom and...” “it doesn’t bother me,” “it bothers me a little,” “it bothers me,” “it bothers me a lot.” Circulating levels of the monocyte activation marker soluble CD14 (sCD14), inflammatory marker interleukin-6 (IL-6), and coagulation marker D-dimer were determined from blood specimens. Here, IL6 is linked to insomnia.