A midday nap may be what your blood pressure needs
If you feel guilty about taking a mid-day siesta, you can stop now.
Midday naps are associated with reduced blood pressure levels, as well as a need for fewer antihypertensive medications, according to new research.
Naps for better blood pressure
“Although [English poet (1757-1827)] William Blake affirms that it is better to think in the morning, act at noon, eat in the evening and sleep at night, noon sleep seems to have beneficial effects,” says Dr Manolis Kallistratos, a cardiologist at Asklepieion Voula General Hospital in Athens, Greece.
He adds that two influential British Prime Ministers were supporters of the midday nap. “Winston Churchill said that we must sleep sometime between lunch and dinner, while Margaret Thatcher didn’t want to be disturbed at around 3:00 pm. According to our study, they were right, because midday naps seem to lower blood pressure levels, and may probably also decrease the number of required antihypertensive medications.”
“Μidday sleep is a habit that nowadays is almost a privileged, due to a nine to five working culture and intense daily routine,” he says. “However, the real question regarding this habit is: Is it only a custom, or is it also beneficial?”
How does a nap affect blood pressure?
The purpose of this prospective study was to assess the effect of midday sleep on blood pressure (BP) levels in hypertensive patients. The study included 386 middle aged patients (200 men and 186 women, average age 61.4 years) with arterial hypertension.
The following measurements were performed in all patients: midday sleep time (in minutes), office BP, 24 hour ambulatory BP, pulse wave velocity, lifestyle habits, body mass index (BMI) and a complete echocardiographic evaluation, including left atrial size.
After adjusting for other factors that could influence BP such as age, gender, BMI, smoking status, salt, alcohol, exercise and coffee, the researchers found that midday sleepers had 5% lower average 24 hour ambulatory systolic BP (6 mmHg) compared to patients who did not sleep at all midday. Their average systolic BP readings were 4% lower when they were awake (5 mmHg) and 6% lower while they slept at night (7 mmHg) than non-midday sleepers (Figure 1).
Dr Kallistratos says, “Although the mean BP decrease seems low, it has to be mentioned that reductions as small as 2 mmHg in systolic blood pressure can reduce the risk of cardiovascular events by up to 10%.”
Midday naps associated with reduced blood pressure and fewer medications
The researchers also found that in midday sleepers pulse wave velocity levels were 11% lower and left atrium diameter was 5% smaller. “These findings suggest that midday sleepers have less damage from high blood pressure in their arteries and heart,” says Kallistratos.
The duration of midday sleep was associated with the burden of arterial hypertension. Patients who slept for 60 minutes midday had 4 mmHg lower average 24 hour systolic BP readings and a 2% higher dipping status compared to patients who did not sleep midday. Dippers had an average of 17 minutes more midday sleep than non-dippers.
“Our study shows that not only is midday sleep associated with lower blood pressure, but longer sleeps are even more beneficial,” Kallistratos says. “Midday sleepers had greater dips in blood pressure while sleeping at night, which is associated with better health outcomes. We also found that hypertensive patients who slept at noon were under fewer antihypertensive medications compared to those who didn’t sleep midday.”
“We found that midday sleep is associated with lower 24 hour blood pressure, an enhanced fall of BP in night, and less damage to the arteries and the heart,” he says. “The longer the midday sleep, the lower the systolic BP levels and probably fewer drugs needed to lower BP.”