Power naps and siestas are recommended to keep our bodies energized and alert, especially when a person has not had much sleep. However, taking long naps in the daytime in spite of a regular sleep schedule may be a sign of a health condition.
A study scheduled to be presented on April 3 at the 65th Annual Scientific Session and Expo (ACC.16) of the American College of Cardiology (ACC) suggests that people who take long naps and/or are very tired in the daytime have a higher risk of developing metabolic syndrome.
Power naps are supposed to be between 10 and 30 minutes long, but studies show that a nap longer than 40 minutes in the daytime showed an increase the risk for type 2 diabetes and heart disease. The risk raises sharply after 40 minutes, and 60 to 90 minutes worth of day napping sees the risk increase to 50 percent. On a less scary note, those who day-nap for less than 30 minutes also show a slight risk decrease.
"[Clarifying] the relationship between naps and metabolic disease might offer a new strategy of treatment, especially as metabolic disease has been increasing steadily all over the world," said Dr. Tomohide Yamada.
The study, which will be presented by lead author Yamada at ACC.16, is an extension of his team's previous research that ties excessive sleep and tiredness with metabolic conditions. Specifically, it involves the data of 307,237 Asian and western individuals from countries across the globe.
Participants of the study were asked about their daytime habits, such as if they feel sleepy or excessively tired during day, if they take naps and how long the naps are as well as their medical history, specifically, those relating to type 2 diabetes, heart disease and obesity.
Results showed that, those who admitted to taking naps for more than 40 minutes saw a sharp increase in their risk for metabolic disease, whereas those who napped but made sure to not exceed 30 minutes have steadier charts.
The latest research supports previous studies done by Dr. Yamada's team, which had to do with showing how people's sleeping habits affect their risk for metabolic syndrome. However, Dr. Yamada said more research must be done in order to really verify the data, especially since people nowadays get less sleep due to busy schedules and distractions — technological or otherwise.
"Sleep is an important component of our healthy lifestyle, as well as diet and exercise. Short naps might have a beneficial effect on our health, but we don't yet know the strength of that effect or the mechanism by which it works," he said.
Dr. Yamada and his team still want to take the study further. After all, even with the 307,237 participants they gathered data from, it is still just a speck in the more than 7.4 billion people in the world. What they did manage to show consistently is that a power nap really does decrease the risk for metabolic syndrome. He is also encouraging other research to focus on the potential benefits of power naps to cardiovascular health.
