Although there have been no previous studies on the association between serum magnesium concentration and coagulopathy, our hypothesis that hypomagnesemia is associated with coagulopathy in sepsis might be biologically plausible based on the association of hypomagnesemia with high-mobility group box 1 (HMGB1), a damage-associated molecular pattern and a lethal mediator of sepsis [29] and inflammatory cytokines [13]. Here, HMGB1 is linked to blood coagulation disease.