Numerous studies link poor sleep quality and short duration with an increased risk of contracting acute infections. Most of these studies, however, use subjective sleep measures. Now new, more robust research confirms that short sleep duration increases by around four-fold the risk of contracting the common cold.

Researchers enrolled 164 healthy men and women aged between 18 and 55 years. Wrist actigraphy and diaries captured sleep duration and continuity for seven consecutive days. The researchers then administered nasal drops containing rhinovirus and monitored volunteers for signs of a clinical cold for five days.

Volunteers who slept for less than five hours, or for between five and six hours, were 4.50 and 4.24 times respectively more likely to develop a cold than those sleeping more than seven hours a night. The 66 per cent increase in those sleeping 6.01 to seven hours was not statistically significant.

This association was independent of antibody levels before the challenge with rhinovirus, demographics, season, body mass index, psychological variables (including perceived stress), and practices such as smoking, alcohol consumption and activity.

“Short sleep was more important than any other factor in predicting subjects’ likelihood of catching [a] cold,” said lead author Aric Prather, assistant professor of psychiatry at University of California, San Francisco. “It didn’t matter how old people were, their stress levels, their race, education or income, or if they were a smoker. “With all those things taken into account, statistically sleep still carried the day. Not getting [enough] sleep fundamentally affects your physical health.”

^{(Sleep 2015; 38:1353-9)}