BEIJING, Sept. 7 (Xinhuanet) -- Getting up early in the morning is the good habit of many people for centuries, but early risers are actually at a higher risk of developing heart problems, according to media reports Friday quoting a new Japaese study.

    The study was presented at the World Congress of the World Federation of Sleep Research and Sleep Medicine Societies held in Cairns, Australia.

    People who habitually rose before 5 a.m. had a 1.7 times greater risk of high blood pressure and were twice as likely to develop hardening of the arteries as those who got up two to three hours later, the study found.

    The study, of 3,017 healthy adults aged 23 to 90, also found a possible link between vascular disease and early birds who began the day with vigorous exercise.

    "Rising early to go to work or exercise might not be beneficial to health, but rather a risk for vascular diseases," said the study.

    The study, conducted by researchers from several universities and hospitals in the western Japanese city of Kyoto, revealed a link between wake-up times and a person's cardiovascular condition. The study also noted that early risers were usually older.

    "The results are contrary to the commonly held belief that early birds are in better health," said Mayuko Kadono, a physician at Kyoto Prefectural University of Medicine, who led the study. "We need to find what the causes of this are, and whether exercising after waking early is beneficial."

    Cardiovascular disease, which includes heart attack, stroke and hypertension, is the biggest cause of death globally, according to the World Health Organization, which estimates 20 million people may die from cardiovascular disease every year by 2015, compared with about 17.5 million a decade earlier.

    (Agencies)