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 10percent,” 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.”

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.”

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