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Sleep shortage increases likelihood to catch a cold, study finds

A new study is reaffirming that to avoid getting sick be sure to get enough sleep.

Dr Marla Shapiro, CTV News, Sep 1, 2015

Back to school means getting back into school routines. For some , return to school has already started and for others this marks the week of return to school. Routines are hard to get back into but among the most important is SLEEP. New research is reminding us what we have known for a while- that sleep is critical for good health. But now a new study is reaffirming that: to avoid getting sick, be sure to get enough sleep.

New research found that people who sleep six hours a night or less are four times more likely to catch a cold when exposed to the virus, compared to those who spend more than seven hours a night. A single hour translated into the difference between getting a cold and now as we head toward cooler weather and crowding, colds generally increase.

This is interesting as this is the first study to use objective sleep measures to connect people's natural sleep habits and their risk of getting sick. The authors found that "short sleep was more important than any other factor in predicting subjects' likelihood of catching cold. What struck me even more what that it didn't matter how old people were, their stress levels, their race, education or income which typically we tend to find as modifiers for disease risk. It didn't matter if they were a smoker. With all those things taken into account, statistically sleep still was the most significant predictor of getting a cold!

The study, "Behaviorally assessed sleep and susceptibility to the common cold," appears online and in the September issue of the journal Sleep.

The Centers for Disease Control and Prevention call insufficient sleep a public health epidemic. Poor sleep has been linked with car crashes, industrial disasters and medical errors. In a new 2015 sleep poll study done by the National Sleep Foundation- this was what was found-

Those who say they have very good or excellent health and quality of life report sleeping 18 to 23 minutes longer on average in the past week than those who rate their health and quality of life as just good, fair or poor. Indeed, reported sleep duration and quality decline linearly with each health rating, showing that perceptions of one’s sleep and health are deeply related.

The study pointed out that sleep quality and duration should be considered a vital sign, as they are strong indicators of overall health and quality of life.

Those who said they were very or extremely motivated to get enough sleep reported sleeping 36 more minutes per night across the week compared with others (7.3 vs. 6.7 hours). Even among those with pain, a higher motivation to get sleep was associated with longer sleep durations and better sleep quality.

Did you know that poor sleep is linked to chronic illnesses, disease susceptibility and even premature death. Previous studies have shown that people who sleep fewer hours are less protected against illness after receiving a vaccine. Other studies have confirmed that sleep is among the factors that regulate T-cell levels.

What did this study do?

Researchers recruited 164 volunteers from the Pittsburgh, PA, area between 2007 and 2011. The recruits underwent two months of health screenings, interviews and questionnaires to establish baselines for factors such as stress, temperament, and alcohol and cigarette use. The researchers also measured participants' normal sleep habits a week prior to administering the cold virus, using a watch-like sensor that measured the quality of sleep throughout the night.

The researchers then sequestered volunteers in a hotel, administered the cold virus via nasal drops and monitored them for a week, collecting daily mucus samples to see if the virus had taken hold.

They found that subjects who had slept less than six hours a night the week before were 4.2 times more likely to catch the cold compared to those who got more than seven hours of sleep, and those who slept less than five hours were 4.5 times more likely.

The study shows the risks of chronic sleep loss better than typical experiments in which researchers artificially deprive subjects of sleep, said Prather, because it is based on subjects' normal sleep behavior. "This could be a typical week for someone during cold season," he said.

The new data add yet another piece of evidence that sleep should be treated as a crucial pillar of public health, along with diet and exercise, the researchers said.

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