LOS ANGELES, Jan. 13 (Xinhua) -- Getting less than seven to eight hours of solid sleep might increase the risk of catching cold, a new study has found.

    The risk of catching cold might rise by three times for people who get less than seven hours of sleep a night, researchers at Carnegie Mellon University in Pittsburgh said in the study.

    If people sleep poorly, the risk might increase by five times, said the study published in the Jan. 12 issue of Archives of Internal Medicine.

    In the study, the researchers collected data on 153 men and women from 2000 to 2004. The participants were asked how many hours they slept a night and whether they felt rested. They also asked how much time the participants spent in bed sleeping.

    The participants were then given nose drops containing a virus for the common cold. Five days later, they were asked to report if they had any signs and symptoms of a cold. The researchers also collected mucus samples to test for the virus. After 28 days, the researchers tested the participants' blood samples for antibodies to the virus.

    "Regular sleep habits may play an important role in your immune system's ability to fight off infectious disease," said study lead author Sheldon Cohen, a psychology professor. "Longer sleep duration and better sleep efficiency are both associated with greater resistance to the common cold."

    The study also found that people who sleep seven to eight hours a night have the lowest rates of heart disease and death.