Toronto, Sep 4 (IANS): Eight to nine hours of good quality sleep every night, combined with other healthy lifestyle behaviours, can reduce the negative consequences of stress in kids, suggests new research.

Getting a good night's sleep might buffer the impact of stress on kids' cortisol level, which is a hormone produced in the adrenal gland to regulate the body's cardiovascular, metabolic and immune systems.

While short-term exposure to cortisol prepares the body for the "fight or flight" response, long-term exposure to cortisol can put people at risk for health problems, like heart diseases, weight gain and depression.

"It is important that parents educate their kids at an early age about the importance of consistent and healthy sleep habits," said lead author of the study Jinshia Ly from Concordia University in Montreal, Canada.

For the study, the research team recruited 220 kids aged eight to 18 years old. The participants gave saliva samples from which their cortisol levels were measured.

The kids and their parents also answered questions about stress, sleep habits and bedtime routines.

The researchers found that poorer sleep quality, regardless of how long kids spent sleeping, promoted the negative effects of stress on their cortisol levels.

?gSleeping throughout the night without waking up, feeling rested in the morning, and absence of sleep problems, such as nightmares, apnea and snoring, are examples of a better quality sleep," Ly noted.

The study was published in the journal Psychoneuroendocrinology.