Heart attacks that mostly happen in the morning tend to be more severe than cardiac arrests at night, warn researchers.
The study, published in the journal Trends in Immunology,discusses how time of the day affects severity of afflictions, ranging fromallergies to heart attacks. For example, studies showed that adaptive immuneresponses — in which highly specialised, pathogen-fighting cells develop overweeks — are under circadian control.
Researchers compiled studies, predominantly in mice, thatlooked at the connection between circadian rhythms and immune responses.”This is ‘striking’ and should have relevance for clinical applications,from transplants to vaccinations,” said study senior author ChristophScheiermann, Professor at the University of Geneva in Switzerland.
According to researchers, in both humans and mice, thenumbers of white blood cells also oscillate in a circadian manner, raising thequestion whether it might be possible one day to optimise immune responsethrough awareness and utilisation of the circadian clock.
For the study, researchers looked into separate studies thatcompared immune cell time-of-day rhythms under normal conditions, inflammationand disease.
“Investigating circadian rhythms in innate and adaptiveimmunity is a great tool to generally understand the physiological interplayand time-dependent succession of events in generating immune responses,”said Scheiermann.”The challenge lies in how to channel ourgrowing mechanistic understanding of circadian immunology into time-tailoredtherapies for human patients,” Scheiermann remarked.