U.S. adults who sleep no more than five hours per night or who have a diagnosed sleep disorder are more likely to have suffered a recent cold than those who sleep more, according to a new study.
“In many countries, particularly western countries, sleep takes a back seat to productivity, which may make some sense in the short term but certainly not the longer term,” said coauthor Aric A. Prather of the Center for Health and Community at the University of California, San Francisco. “Sleep happens with whatever time is left after all of the other ‘necessary’ tasks are attended to.”
Getting too little sleep can have a direct impact on cardiovascular, endocrine and immune functioning that may increase disease risk over time, Prather told Reuters Health by email.
In addition, “poor sleep may lead to health behaviors that also raise one’s risk for poor heath,” he said. “Short sleepers are less likely to exercise and more likely to engage in less than ideal nutrition that, again over time, can affect health.”
One quarter had told a doctor about trouble sleeping and 7 percent had been diagnosed with a sleep disorder.
Over the previous 30 days, 19 percent of ‘short sleepers’- that is, those with five or fewer hours of sleep per night – had a head or chest cold, compared to 16 percent of those who slept for six hours and 15 percent of those who got seven or more hours.
After accounting for factors like age, sex, race, education level and smoking status, those with a diagnosed sleep disorder were also more likely to have had a cold or infection than others, the researchers reported in JAMA Internal Medicine.
“This data does not allow us to know whether sleep causes an increase in susceptibility to respiratory infections,” only that the two are somehow connected, Prather said.
Chronic poor sleep increases the risk of obesity, diabetes and heart disease, he said.
“Sleep deprivation studies in the laboratory have clear effects on immune function, and other clinical studies have shown that poor sleep before exposure to the cold virus influences the risk of actually developing a cold,” said Dr. Daniel J. Buysse of the University of Pittsburgh School of Medicine, who was also not part of the new research.