Less Sleep, More Colds

A recent study has me thinking. One of my changes for 2009 (not resolution, mind you...just a change) is to add more sleep. That is more sleep each night and more each week. A number of studies have looked at the effects and the toll of lack of sleep. It seems that from cardiovascular to immunologic systems are among the two at most risk. See Sleep Habits and Susceptibility to the Common Cold as published in The Archives of Internal Medicine.

Here is a summary of findings...

• The less a person slept, the more likely he or she was to develop a cold (there was a graded association between infection rate and average sleep duration).


• Participants who slept fewer than 7 hours were 2.94 times more likely to develop a cold than those who had 8 hours or more sleep.


• The more efficiently a person slept (more of the time in bed actually spent asleep), the less likely he or she was to develop a cold (i.e. there was also a graded association between sleep efficiency and rate of infection).


• Participants whose sleep efficiency feel below 92 per cent were 5.50 times more likely to develop a cold than those whose efficiency was 98 per cent or more.


• Feeling rested was not linked to rate of infection.


• These relationships could not be explained by the potential counfounders such as levels of virus-specific antibodies beforehand, demographics, the season of the year, body mass index, socioeconomic status, health behaviours, and psychological variables.