According to the British newspaper “The Times” reported on July 25, a study shows that people who are used to napping may be at risk of high blood pressure and stroke.
Researchers looked at data from 358,000 people in the U.K. who answered questions about how they slept during the day.
Those who had to nap most of the time had a 12 percent higher chance of developing high blood pressure. During the 11-year follow-up period, they were 24 percent more likely to have a stroke than people who never napped.
Compared to people who don’t nap, those who do occasionally are 7 percent more likely to develop high blood pressure and 12 percent more likely to have a stroke.
Most of the time to nap less than one in 20 adults, three out of five said they rarely or never nap.
People who habitually nap are predominantly men, smokers, daily drinkers, insomniacs and snorers. They were also more likely to be overweight and to have lower levels of education and income than those who did not nap.
Most of these survey participants between the ages of 40 and 69 did not change the frequency of napping throughout the study period.
Younger nappers had higher odds of developing health risks compared to older individuals. People under 60 who had to nap most of the time had a 20 percent higher risk of developing high blood pressure, while nappers over 60 had only a 10 percent higher risk of developing high blood pressure.
The study was observational and could not prove cause and effect. Experts say napping itself may not be harmful, but it is an indicator of poor health.
The study on napping was published in the American Heart Association’s journal Hypertension, and the association’s Dr. Michael Grandner said, “This study echoes other findings that more naps seem to reflect an increased risk of heart disease and other conditions.”
The doctor said, “This may be because, while napping itself is not harmful, many people nap probably because they don’t sleep well at night. Poor nighttime sleep quality is associated with poor health, and napping is not enough to compensate.”
The new study did not refer to the duration of naps, only the frequency with which people took them.
About one-third of British adults have hypertension, which is blood pressure above 140/90 mmHg. If left untreated, this can increase the risk of serious diseases, such as heart disease and stroke.
The study concluded, “The exact biological mechanisms underlying the effects of daytime napping on blood pressure regulation or stroke are not known. Little is known about the underlying mechanisms, but this may include the long-term effects of increased inflammation or peak blood pressure after napping.”