IL6 and Airway obstruction: Mechanistically, circadian fluctuations in inflammatory cytokines and mediators may be responsible for exacerbating airway obstruction during the night (12), and some of these inflammatory mediators (e.g., histamine, cysteinyl leukotriene, and interleukin-6) also participate in the regulation of sleep-wake cycle and circadian rhythm, resulting in frequent arousals and sleep disturbances (13, 28).