The Influence of Circadian Rhythm on Cardiovascular Diseases

Cardiovascular and cerebrovascular diseases are common acute clinical conditions characterized by sudden onset, rapid progression, high rates of disability and mortality, and poor prognosis, often posing life-threatening risks. Ischemic heart disease and stroke rank as the first and second leading causes of death worldwide, respectively. The circadian rhythm, governed by a hierarchical system of central and peripheral oscillators, regulates biological activities in a time-dependent manner. The dominant central pacemaker, located in the suprachiasmatic nucleus of the hypothalamus, synchronizes with geophysical time through light signals. Peripheral tissues, in turn, are influenced by this master pacemaker via neuronal and humoral signals, which coordinate circadian physiology and behavior. Cardiovascular physiology exhibits distinct circadian rhythms, with parameters such as body temperature and blood pressure showing significant diurnal variations. Coagulation function, blood pressure, vascular function, endothelial health, and lipid metabolism all exhibit significant diurnal rhythms. Studies have indicated that individuals engaged in shift work are more susceptible to abnormalities in vascular physiological factors, and atherosclerosis has been clearly associated with circadian rhythm disruption. Understanding the circadian mechanisms of the vascular system may represent an important avenue for preventing and treating cardiovascular disorders. By leveraging these rhythms, clinicians can optimize drug administration timing (e.g., chronotherapy with aspirin) to further reduce cardiovascular event rates and improve therapeutic outcomes. This article not only clarifies the circadian physiological patterns of the vascular system but also elucidates the correlation between vascular physiological abnormalities and shift work, as well as the potential risks of circadian disruption in the development of atherosclerosis.