This Article Free upon publication Full Text Full Text (PDF) All Versions of this Article: 118/3/284    most recent CIRCULATIONAHA.108.771246v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Foerch, C. Search for Related Content PubMed PubMed Citation Articles by Foerch, C. Pubmed/NCBI databases Medline Plus Health Information Stroke Related Collections Acute Cerebral Hemorrhage Acute Cerebral Infarction Related Article

(Circulation. 2008;118:284-290.)
© 2008 American Heart Association, Inc.

Stroke

Abrupt Shift of the Pattern of Diurnal Variation in Stroke Onset With Daylight Saving Time Transitions

Christian Foerch, MD; Horst-Werner Korf, MD; Helmuth Steinmetz, MD; Matthias Sitzer, MD, for the Arbeitsgruppe Schlaganfall Hessen (ASH)

From the Department of Neurology (C.F., H.S., M.S.) and Institut fuer Anatomie II (H.-W.K.), Goethe University, Frankfurt am Main, Germany.

Correspondence to Christian Foerch, MD, Department of Neurology, Schleusenweg 2-16, 60528 Frankfurt am Main, Germany. E-mail foerch{at}em.uni-frankfurt.de

Received February 4, 2008; accepted May 12, 2008.

Background— Stroke onset shows a pattern of diurnal variation, with a peak in morning hours. Rhythmic changes in blood pressure, hormones, and other parameters have been suggested as underlying mechanisms, but exogenous factors such as increasing physical activity after awakening may also be of relevance. To characterize the impact of external clock changes on the rhythmic variation in stroke onset, this parameter was recorded in patients during transition periods into and out of Daylight Saving Time (DST).

Methods and Results— The present study was based on a prospective stroke registry in Germany that contains time points of stroke onset from 44 251 patients admitted between 2000 and 2005. To achieve a uniform timeline, time points of stroke onset were set back from Central European Summer Time (CEST) to Central European Time (CET) for patients admitted during DST periods. Compared with the last week before the clock change, transition to or from DST resulted in an immediate shift of stroke onset time points within the first week after the clock change in reference to the uniform timeline (transition from CET to CEST –60 minutes for the time points in both the 25th and 50th percentiles of the diurnal pattern, P<0.001; transition from CEST to CET +60 minutes for the time points in both the 25th and 50th percentiles, P<0.001; patients pooled on a weekly basis). A significant shift was already present the first and second day after the transitions (ie, Monday and Tuesday).

Conclusions— Transition to or from DST is coupled with an immediate shift in the time pattern of stroke onset. This strengthens the idea that exogenous factors associated with awakening are important determinants of the pattern of diurnal variation of stroke onset, because entrainment of the human circadian clock within hours is unlikely.

---

 

CLINICAL PERSPECTIVE

Related Article:

Clinical Summaries
Circulation 2008 118: 211-212. [Extract] [Full Text]