Table 3.

Summary

Many physiology and pathophysiology of disease processes exhibit circadian patterns, involving behavioral or functional variations that cycle every 24 h.

Immune responses due to sepsis vary at different times of the day. Circadian disruption, demonstrated by genetics models and sleep deprivation in humans, affects the severity of immune response.

Airflow obstruction tends to worsen in the early morning, corresponding to circadian changes of pulmonary function and abundance of immune cells in the airway.

Upper airway collapsibility and apnea length follow an endogenous circadian pattern in obstructive sleep apnea and are worse in early morning.

Many properties of tumorigenesis, such as cell proliferation and DNA repair, are regulated in a circadian fashion. Chronic circadian disruption in shift workers increases cancer risk.

Chronotherapy, the practice of giving treatment at specific times, has been shown to be beneficial, with reduced toxicity in treatment of asthma and chemotherapy for various malignancies.