Napping may be as good as drugs for lowering blood pressure
A midday nap may be just what you need, not just to boost your energy levels but also to lower high blood pressure. This, at least, is what new research from Greece suggests.
When the afternoon slump hits in the middle of a busy workday, many of us may feel tempted to catch some shut-eye in a quiet corner.
Daytime napping can definitely help boost our energy levels and productivity for the rest of the workday, but does it bring any other health benefits?
A new study that investigators from the Asklepieion General Hospital in Voula, Greece conducted now suggests that taking a nap at midday can effectively help people lower their blood pressure levels.
One of the study researchers, Dr. Manolis Kallistratos, is due to present the findings at the American College of Cardiology's 68th Annual Scientific Session in New Orleans, LA next Monday.
"Midday sleep appears to lower blood pressure levels at the same magnitude as other lifestyle changes. For example, salt and alcohol reduction can bring blood pressure levels down by 3 to 5 [millimeters of mercury (mmHg)]," reports Dr. Kallistratos.
In this study, the investigators worked with 212 participants who had a mean blood pressure of 129.9 mm Hg. According to guidelines from the National Heart, Lung, and Blood Institute, a person has high blood pressure if their readings of systolic blood pressure (pressure during a heartbeat) are 140 mm Hg or higher, and their readings of diastolic blood pressure (pressure between heartbeats) are 90 mm Hg or higher.
The participants were, on average, 62 years old, and close to one in four of them smoked, had a diagnosis of type 2 diabetes, or both.
Significant drop in blood pressure
Dr. Kallistratos and team split the participants into two groups — one that practiced midday napping and one that did not take up this practice.
Over 24 consecutive hours, the researchers took note of the participants' blood pressure measurements, the duration of their midday naps, their general lifestyle choices (such as alcohol consumption and physical activity), and their pulse wave velocity, which measures artery stiffness.
To obtain accurate blood pressure measurements from the participants throughout the day, the investigators asked them to wear ambulatory blood pressure monitoring devices.
Dr. Kallistratos and colleagues also adjusted for potential confounding factors that could affect blood pressure, such as age, biological sex, prescription medication, and lifestyle choices. They noted that there were no significant differences between how many blood pressure drugs participants in the two groups took.
The researchers found that people who took a daytime nap saw a 5.3 mm Hg drop in systolic blood pressure, which, the researchers explain, is about as much as someone could expect when taking blood pressure medication or making certain lifestyle changes to lower blood pressure.
Moreover, the team adds that each additional 60 minutes of napping time reduced average 24-hour systolic blood pressure by 3 mm Hg. Dr. Kallistratos explains that taking low doses of specialized drugs can lower a person's blood pressure levels by about 5–7 mm Hg on average.
"These findings are important because a drop in blood pressure as small as 2 mm Hg can reduce the risk of cardiovascular events, such as heart attack, by up to 10 percent," says the researcher.
"Based on our findings, if someone has the luxury to take a nap during the day, it may also have benefits for high blood pressure," he adds, noting that "[n]apping can be easily adopted and typically doesn't cost anything."
Researchers are confident in their findings
The researchers note that this is the first time that anyone has studied the effects of daytime naps on a person's blood pressure levels. Although the team encourages further research to replicate and validate the current results, its members are confident that their study offers important new information.
Dr. Kallistratos and colleagues explain that they made an effort to recruit study participants who reasonably controlled their blood pressure levels to ensure that their findings would be credible.
"The higher the blood pressure levels, the more pronounced any effort to lower it will appear," explains Kallistratos.
He continues, "By including people with relatively well-controlled blood pressure, we can feel more confident that any significant differences in blood pressure readings are likely due to napping."
The researchers observe that the results of their study should provide grounds for people to indulge in midday naps with less of a sense of guilt.
"We obviously don't want to encourage people to sleep for hours on end during the day," says Dr. Kallistratos, "but, on the other hand, they shouldn't feel guilty if they can take a short nap, given the potential health benefits."
"Even though both groups [of participants] were receiving the same number of medications and blood pressure was well controlled, there was still a significant decrease in blood pressure among those who slept during midday."
Dr. Manolis Kallistratos