Chronobiology studies biological cycles or rhythms. Circadian rhythms are critical for the maintenance of cellular and psychophysiological health. Many health problems are affected by the time of day. For example, the symptoms of rheumatoid arthritis (RA) including joint pain and stiffness are more serious during the morning than at other time (Buttgereit et al., 2015). Such feature may be caused by the circadian cycling of certain cytokines and hormones that are often at the high levels in the morning.
The features of circadian rhythms may be utilized for individualized treatment of diseases. Chronotherapy is the therapeutic method targeting the body’s natural temporal cycles such as the circadian rhythms to improve the treatment effects. Such methods can help promote the therapeutic results and diminish side effects.
For example, in the glucocorticoid therapy of RA, the factor of the nocturnal increase of the blood cytokine levels such as IL-6 can be considered to decrease the seriousness of the symptoms including morning stiffness and pain (Buttgereit et al., 2015). In addition, chronotherapy at certain time of day may also help with other symptoms including depression and sleep disorders among RA patients.
Although chronotherapy has not been included in standard treatment guidelines, recent studies such as those in chronobiology have shown its potential benefits. With the development of translational medicine, the discoveries in chronobiology can be transformed into better therapies in the clinical practice.
Buttgereit F, Smolen JS, Coogan AN, Cajochen C. Clocking in: chronobiology in rheumatoid arthritis. Nat Rev Rheumatol. 2015 Jun;11(6):349-356. doi: 10.1038/nrrheum.2015.31.