IL6 and obstructive sleep apnea syndrome: Furthermore, the underlying mechanism of the relationship between LSD and mortality risk may involve elevated levels of inflammatory markers, such as interleukin-6 and C-reactive protein.35 In addition, obstructive sleep apnea is characterized by long sleep duration, sleep disturbance, and daytime dysfunction and is also associated with increased risk of mortality and CVD.36 Thus, obstructive sleep apnea can mediate long sleep duration and mortality risk.