Circadian rhythms in medicine: unraveling the time dimension for optimized healthcare outcomes, disease management and prevention

Circadian rhythms (CRs), the endogenous biological oscillations that occur approximately every 24 hours, are integral to human health. While physicians typically diagnose and treat diseases without considering temporality, time may be a critical factor in medical practice. A growing body of evidence shows that molecular clocks regulate 24-hour CRs in vital cardio-metabolic, endocrine, immunological, and behavioral processes. In addition, a growing number of studies indicate a link between circadian rhythm disruption (CRD), common in modern, always-on societies, and the prevalence, severity, and progression of several non-communicable diseases, including cancer, cardiovascular disease, and mental disorders. In addition, maternal chronodisruption has been associated with intrauterine growth restriction (IUGR). IUGR infants, who account for 3-7% of all births worldwide and 24% of newborns in developing countries, are predisposed to non-communicable diseases (NCDs) in adulthood, such as cardiovascular disease, hypertension, metabolic syndrome, and behavioral problems, in line with the Developmental Origins of Health and Disease (DOHaD) hypothesis, with significant societal implications. Circadian medicine aims to incorporate knowledge of 24-hour biological rhythms not only to optimize diagnostic and therapeutic strategies focusing on drug delivery, disease management, and overall patient well-being but also to prevent circadian-related disorders. The potential for integrating chronobiology into clinical practice begins with a deeper understanding of CRs and their impact on human health and disease, ultimately enabling more personalized healthcare, improved patient outcomes, and reduced healthcare costs. This burgeoning field of medicine promises the significant potential to improve disease prevention, diagnosis, and treatment, benefiting patients and healthcare systems alike.