Author + information
- Alberto Dominguez-Rodriguez, MD, PhD⁎ (, )
- Martin Garcia-Gonzalez, MD and
- Pedro Abreu-Gonzalez, MD
- ↵⁎Hospital Universitario de Canarias, Cardiology, Coronary Care Unit, Ofra s/n, La Cuesta, La Laguna, Tenerife E-38320, Spain
We read with great interest the recent report by Moreno P et al. (1) concerning inflammation as one of the primary pathophysiologic processes in cardiovascular disease. However, we would like to add two comments.
First, it has also been clearly documented that the occurrence of coronary syndromes during the day are not uniform; rather, they occur with rhythmic variation. The existence of a circadian rhythm in the acute coronary syndrome suggests that the problem might, in some way, be associated with, or started by, physiological rhythms, with peak activity at certain parts of the day or night. Numerous studies have tried to establish the cause for this circadian rhythm and its clinical and therapeutic implications (2). Experimental studies have shown that both immune cell number and immune functions may vary during the 24-h circadian period (3).
Second, the increase in mortality from cardiovascular events in winter might be due to alterations in the biological clocks located in the suprachiasmatic nuclei, whose rhythm is determined by day–night alternation, that is, by the light/darkness cycles. These cycles regulate functions such as the secretion of cortisol (4), blood pressure (5), vasomotor tone (6), tissue plasminogen activator (7), and pro-inflammatory cytokines (8,9).
Therefore, considering the potential association among inflammation and circadian rhythm, the presence of a variability during the 24 h of inflammatory and immunologic functions would permit, hypothetically, one to identify the light/dark times in which any peak of inflammatory activity could be associated with a greater incidence of cardiovascular events.
This LE is paired with LR JACC 081705-3080
- American College of Cardiology Foundation
- Moreno P.R.,
- Fuster V.
- Vernikos-Danellis J.,
- Winget C.M.