Cronobiología y aplicaciones médicas (II). Ritmos ultradianos e infradianos. Cronomedicina

Abstract

Chronobiology is a discipline that investigates how biological processes are structured in time cycles in response to environmental variations, including circadian, ultradian, and infradian rhythms. Despite the fact that research has paid more attention to circadian rhythms, ultradian and infradian rhythms are also key to a comprehensive understanding of chronobiology. Ultradian rhythms, with cycles of less than 24 hours, tend to be anticipatory mechanisms that respond to unpredictable disturbances, notable among which are circahoral rhythms (cycles between 20 minutes and 2 hours) and circatidal rhythms (approximately 12 hours). Infradian rhythms include cycles greater than one day, notable among which are circaseptal rhythms (approximately 7 days), circalunar rhythms (28 – 32 days), and seasonal or circannual rhythms (regulated by temporal processes associated with the seasons of the year). The involvement of these rhythms in different physiological and pathological processes has also been demonstrated, thus supporting the relevance of considering both as an element of study in the area of chronobiology. On the other hand, chronomedicine is a translational area that is in expansion. It attempts to apply a basic knowledge of chronobiology to clinical practice, influencing sleep management and the pharmacological and non-pharmacological approach to different diseases. This second part will describe the relevance of ultradian and infradian rhythms in health and disease. It will also describe the underlying mechanisms of these biological rhythms. In addition, it will discuss how the knowledge of these rhythms and of circadian rhythms can be applied in the medical setting, exploring possible translational focuses based on chronobiology for the treatment and management of diseases. It will also highlight lifestyle-based interventions or specific aspects associated with women's menstrual cycles.