Toronto, Dec 5 (IANS): Do you sleep too much or do you not get sufficient sleep? If so, there is bad news. The amount of time you sleep, including daytime naps, is associated with the risk of developing cardiovascular disease (CVD) and death, a new study warns.

The study found that people who slept for longer than the recommended duration of six to eight hours a day had an increased risk of dying or developing heart disease or stroke.

"Our study shows that the optimal duration of estimated sleep is six to eight hours per day for adults," said Chuangshi Wang, postdoctoral student from the McMaster University in Canada.

"Too little sleep could be an underlying contributor to death and cases of cardiovascular disease, and too much sleep may indicate underlying conditions that increase risk," Wang added.

Although daytime napping was associated with higher risks of death or cardiovascular problems in those with sufficient or longer sleep at night, this was not the case in people who slept under six hours at night as it compensated for the lack of sleep at night and mitigated the risks.

For the study, the team looked at a total of 116,632 adults aged between 35 and 70.

The findings, published in the European Heart Journal, showed that compared to people who slept for the recommended time, those who slept a total of eight to nine hours a day had a five per cent increased risk of developing the disease.

In addition, people sleeping between nine and ten hours a day had an increased risk of 17 per cent and those sleeping more than 10 hours a day had a 41 per cent increased risk.

Furthermore, they also found a nine per cent increased risk for people who slept a total of six or fewer hours.

Importantly, the team also found that for every 1,000 people sleeping six or fewer hours a night, 9.4 per cent developed CVD or died per year.

This occurred in 7.8 per cent of those sleeping six to eight hours, 8.4 per cent of those sleeping eight to nine hours, 10.4 per cent of those sleeping nine to 10 hours and 14.8 per cent of those sleeping more than 10 hours, findings further revealed.

"The general public should ensure that they get about six to eight hours of sleep a day. If you sleep too much regularly, then you may want to visit a doctor to check your overall health," Salim Yusuf, Professor from the varsity noted.