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Circadian variation of stroke onset in Hong Kong Chinese: a hospital-based study

R T Cheung1, W Mak, K H Chan

  • 1Division of Neurology, University Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong. rtcheung@hkucc.hku.hk

Cerebrovascular Diseases (Basel, Switzerland)
|July 4, 2001
PubMed

Insights

Stroke and transient ischaemic attack (TIA) onset shows significant daily rhythms. Ischaemic stroke or TIA risk peaks in the morning, while intracerebral haemorrhage risk is highest in the afternoon.

Area of Science:

  • Neurology
  • Circadian Biology
  • Epidemiology

Background:

  • Stroke and transient ischaemic attack (TIA) are significant public health concerns.
  • Understanding the temporal patterns of stroke onset may inform preventative strategies.
  • Previous research suggests potential daily variations in cardiovascular events.

Purpose of the Study:

  • To investigate the circadian variation in the onset of stroke and TIA.
  • To analyze temporal patterns for different stroke subtypes, including ischaemic stroke (IS) and intracerebral haemorrhage (ICH).
  • To compare circadian patterns between patients with and without a history of stroke or TIA.

Main Methods:

  • Retrospective analysis of Hong Kong Chinese patients admitted between October 1996 and July 1999.
  • Onset times were categorized into four 6-hourly periods starting from midnight.
  • Statistical analysis to determine significant circadian variations in event onsets.

Main Results:

  • Significant circadian variation in onset was observed for all stroke types, TIA, IS, ICH, and IS subtypes.
  • The highest risk period for IS or TIA onset was between 6 a.m. and noon.
  • The highest risk period for ICH onset was between noon and 6 p.m.
  • No significant difference in circadian variation was found between patients with and without prior TIA or stroke.

Conclusions:

  • This study confirms a significant circadian variation in the onset of various stroke types and TIA in Hong Kong Chinese patients.
  • Distinct temporal patterns exist for ischaemic stroke/TIA versus intracerebral haemorrhage.
  • These findings highlight the importance of considering daily rhythms in stroke research and clinical management.

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