The old saying ‘Early to bed, early to rise, makes a man healthy and wise’ has been proved wrong by a study in Japan. The study conducted by Mayuko Kadono at Kyoto Prefectural University, analyzed 3,066 healthy adults averaging 57.2 years old. According to it, even a one-hour advance in the wake-up time of study participants increased the risk of hardening of the arteries by 1.2 times without a change in sleep duration.

The results, which underscore Kadono’s previous study that had shown links between vascular dysfunction and waking up before 5 a.m, were also presented at the 6th World Congress of the World Sleep Federation, which opened in Kyoto, Japan, on Oct. 16 2011.

According to the World Health Organization, Cardiovascular disease, which includes heart attack, stroke, and high blood pressure, may kill 23.6 million people by 2030, rising from 17.3 million in 2008. Kadono, an endocrinologist had also stated that as people age, they go to bed earlier and hence rise earlier and earlier bedtimes and earlier wake-up times had a larger influence on vascular condition than sleep duration. Age- associated changes of rhythm and sleep forms might influence vascular condition, according to him. The study also concluded that people who had difficulty falling or maintaining sleep at night had a higher prevalence of hypertension.