title: Circadian variation of stroke onset in Hong Kong Chinese: a hospital-based study.
abstract: Circadian variation of onset of transient ischaemic attack (TIA) or stroke during four 6-hourly periods starting from midnight was studied in Hong Kong Chinese patients admitted to a regional hospital between October 1996 and July 1999. The onset was classifiable into one of the 6-hourly periods in 832 of 905 patients; patients with unclassifiable onset were more likely to have lacunar infarct and less likely to have intracerebral haemorrhage (ICH). There was a significant circadian variation of onset in all strokes and TIA, TIA alone, ischaemic stroke (IS), ICH and different IS subtypes. The risk of onset was greatest between 6 a.m. and noon for IS or TIA, but between noon and 6 p.m. for ICH. There was no difference in the circadian variation between patients with and without prior TIA or stroke. This hospital-based study revealed a significant circadian variation of onset in different types and subtypes of stroke.
authors: Division of Neurology, University Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong. rtcheung@hkucc.hku.hk
authors: R T
authors: RT
authors: Cheung
authors: W
authors: W
authors: Mak
authors: K H
authors: KH
authors: Chan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006723:Hong Kong; D006761:Hospitals; D006801:Humans; D002546:Ischemic Attack, Transient / Q000401:mortality / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D020521:Stroke / Q000401:mortality / Q000503:physiopathology*; D013997:Time Factors