Sleep under 7 or over 9 hours raises cardiometabolic disease risk 4%

October 4, 2026 at 07:55 AM1 min

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A study in Sleep Medicine found that sleeping less than seven or more than nine hours raises the risk of a first cardiometabolic disease by 4%. The risk of two or more such diseases rises by 10%, and death from any cause by 7%. The findings are based on 10-year data from the China Kadoorie Biobank.

Key Facts

Sleeping less than seven or more than nine hours raises the risk of a first cardiometabolic disease by 4%.
The risk of developing two or more cardiometabolic diseases increases by 10% for those outside the seven-to-nine-hour range.
All-cause mortality is 7% higher among people who sleep less than seven or more than nine hours.
The study analyzed 10-year data from the China Kadoorie Biobank and was published in Sleep Medicine.
Cardiometabolic diseases include myocardial infarction, stroke, diabetes, kidney disease, and non-alcoholic fatty liver disease.

Study Design

Researchers analyzed data from the China Kadoorie Biobank over a 10-year observation period. They compared participants who slept seven to nine hours per day with those who slept less or more. The study was published in the journal Sleep Medicine.

Risk Findings

Sleeping less than seven or more than nine hours raised the risk of a first cardiometabolic disease by 4%. The risk of two or more such diseases increased by 10%, and all-cause mortality by 7%. The highest risks were observed in people with disrupted sleep patterns who alternated between too little and too much sleep. The association held across different participant groups, according to the authors.

Causal Interpretation

Sleep duration does not directly cause disease but acts as one contributing factor, the authors noted. Cardiometabolic diseases include myocardial infarction, stroke, diabetes, kidney disease, and non-alcoholic fatty liver disease.