Study participants who napped regularly during the day were 12% more likely to develop high blood pressure and 24% more likely to have a stroke, compared with people who never napped. If the participant was under the age of 60, the risk of high blood pressure was up to 20%. High blood pressure is associated with a higher risk of cardiovascular disease and stroke, one of the world’s leading causes of death.
Smokers and drinkers often nap
Even when type 2 diabetes, existing high blood pressure, high cholesterol, sleep disturbances and night work were taken into account, the results held up, the study says.
Most naps were taken by those who smoked, drank alcohol daily, snored, “identified as a night owl” or suffered from insomnia.
The study was based on data from 360,000 participants who gave information to the UK Biobank about their napping habits between 2006 and 2010. The participants had their blood, urine and saliva analyzed on a regular basis. However, only the nap frequency was polled, not the length of the nap.
Alarm signal
“While napping in itself isn’t harmful, it seems that many people who take naps do it because they don’t sleep well at night. Poor sleep has been linked to poorer health, and naps can’t fix that,” clinical psychologist Michael Grandner told CNN in a statement.
“The results show that taking a nap increases the risk of high blood pressure and stroke, even when you consider all the other variables associated with the risk of cardiovascular disease and stroke,” said Dr. Phyllis Zee, director of the Center for Circadian and Sleep Medicine in Chicago, who was not involved in the study. Zee emphasizes to CNN that health professionals should check their patients’ sleeping habits often enough.