Lack of sleep connected to catching a cold, new research confirms

If you sleep six hours a night or less, you are 4 times more likely to catch a cold
September 1, 2015

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If you sleep six hours a night or less a night, you are 4.2 times more likely to catch a cold (five hours or less, 4.5 times more likely) compared to those who sleep more than seven hours in a night.

That’s the finding of a study by  Carnegie Mellon University’s Sheldon Cohen, the Robert E. Doherty University Professor of Psychology in the Dietrich College of Humanities and Social Sciences, and researchers from UC San Francisco and the University of Pittsburgh Medical Center.

Published in the journal Sleep, the researchers used objective sleep measures. For the study, 164 adults underwent two months of health screenings, interviews and questionnaires to establish baselines for factors like stress, temperament, and alcohol and cigarette use. The researchers also tracked their sleep patterns for seven days using a watch-like sensor that measured the duration and quality of sleep throughout the night.

Then, the participants were sequestered in a hotel, administered the cold virus via nasal drops and monitored for a week, collecting daily mucus samples to see if the virus had taken hold.

“Sleep goes beyond all the other factors that were measured,” Prather said. “It didn’t matter how old people were, their stress levels, their race, education or income. It didn’t matter if they were a smoker. With all those things taken into account, statistically sleep still carried the day and was an overwhelmingly strong predictor for susceptibility to the cold virus.”

Aric Prather, assistant professor of psychiatry at UCSF and lead author of the study, said the study shows the risks of chronic sleep loss better than typical experiments in which researchers artificially deprive subjects of sleep, because it is based on subjects’ normal sleep behavior. “This could be a typical week for someone during cold season,” he said.

Sleep should be treated as a crucial pillar of public health, along with diet and exercise, the researchers said.


Abstract of Behaviorally Assessed Sleep and Susceptibility to the Common Cold

Study Objectives:

Short sleep duration and poor sleep continuity have been implicated in the susceptibility to infectious illness. However, prior research has relied on subjective measures of sleep, which are subject to recall bias. The aim of this study was to determine whether sleep, measured behaviorally using wrist actigraphy, predicted cold incidence following experimental viral exposure.

Design, Measurements, and Results:

A total of 164 healthy men and women (age range, 18 to 55 y) volunteered for this study. Wrist actigraphy and sleep diaries assessed sleep duration and sleep continuity over 7 consecutive days. Participants were then quarantined and administered nasal drops containing the rhinovirus, and monitored over 5 days for the development of a clinical cold (defined by infection in the presence of objective signs of illness). Logistic regression analysis revealed that actigraphy- assessed shorter sleep duration was associated with an increased likelihood of development of a clinical cold. Specifically, those sleeping < 5 h (odds ratio [OR] = 4.50, 95% confidence interval [CI], 1.08–18.69) or sleeping between 5 to 6 h (OR = 4.24, 95% CI, 1.08–16.71) were at greater risk of developing the cold compared to those sleeping > 7 h per night; those sleeping 6.01 to 7 h were at no greater risk (OR = 1.66; 95% CI 0.40–6.95). This association was independent of prechallenge antibody levels, demographics, season of the year, body mass index, psychological variables, and health practices. Sleep fragmentation was unrelated to cold susceptibility. Other sleep variables obtained using diary and actigraphy were not strong predictors of cold susceptibility.

Conclusions:

Shorter sleep duration, measured behaviorally using actigraphy prior to viral exposure, was associated with increased susceptibility to the common cold.