How much sleep do you get? This is your risk of stroke.

There is uncertainty about the optimum sleep duration for risk of different subtypes of stroke and ischaemic heart disease.

The present analyses involved 409,156 adults in the China Kadoorie Biobank study without a prior history of coronary heart disease or stroke or insomnia symptoms.

The associations of sleep duration with CVD types were U-shaped, with individuals reporting 7–8 h of sleep having the lowest risks.

Individuals reporting 7–8 h of sleep had the lowest risks and those who reported having ≤ 5 h or ≥ 10 h of sleep had 10% and 12% higher risks of total stroke and 23% and 22% higher risks of major coronary events (MCE), respectively.

The findings reinforce the importance of adequate sleep duration for prevention of most cardiovascular disease types and of prioritizing adults with abnormal sleep duration for more intensive treatment for prevention of stroke and coronary heart disease.