Research on the sleeping habits of 2,400 adults found that males with dangerously high blood pressure, also known as hypertension, tend to go to bed significantly earlier than those without.
And once in bed, they spend more of the night tossing and turning, researchers at Hiroshima University found.
Men with the condition were found to go to bed on average 18 minutes earlier than those without it.
But the potential extra sleep gained was also found to have no impact on lowering blood pressure.
The average bed time for men with the condition was 11.10pm, while those without went at 11.28pm.
The ‘sleep score’ for males with high blood pressure was 5.3 – a score of five or more indicates a poor night.
For those without, the average was just 4.7.
Dr Nobuo Sasaki, who led the study, said: "Early bed times were associated with hypertension independent of anything else.”
The researchers say men with high blood pressure may prefer going to bed earlier because their health was worse, making them more tired.
But they didn’t rule out the possibility that hypertension alters the body clock.