A study scheduled to be reviewed at the 65th Annual Scientific Session for the American College of Cardiology reports that long naps and daytime sleepiness put an individual at higher risk of developing metabolic syndrome.
Metabolic syndrome is characterized by a collection of conditions that put an individual at risk for developing heart disease, such as high blood pressure, high sugar, high cholesterol, and excess waist fat. This new study showed that naps over 40 minutes were associated with a significant increase in the risk of metabolic syndrome. It was also noted that being excessively tired throughout the day was a risk for the condition as well.
A diagnosis of metabolic syndrome has been drastically increasing throughout the world, and, not surprisingly, napping has grown to be more prevalent as well. Researchers believe that clarifying this relationship between sleeping/tiredness and metabolic syndrome could help both prevent heart disease and improve treatments.
The study was a meta-analysis of 21 observational studies with over 307,000 participants of both Asian and western descent. It was linked to the findings of an earlier study done by Dr. Tomohide Yamada, the lead researcher, which looked at the association between heart disease and type 2 diabetes that was linked to daytime sleepiness and napping.
The participants were asked a series of questions about whether or not they were excessively tired during the day and if they took naps on a regular basis. These answers were compared to those with a diagnosis of heart disease, obesity, and type 2 diabetes.
Researchers found that those who napped for less than 40 minutes did not have an increased risk of developing metabolic syndrome; however, those who went beyond the 40 minutes had a significantly increased risk. Further, a 90-minute nap, as well as excessive tiredness during the day, increased the risk by about 50%. Those who took less than 30-minute naps had a slight dip in their risk of metabolic disease.
The previous study noted that napping for an hour increases the risk of diabetes by 50%. This did not, however, show any link or correlation to obesity, despite the clear connection between obesity, diabetes, and metabolic syndrome. In a completely different study done in 2015 by Dr. Yomada and his colleagues, it was found that those who took longer than one-hour naps were 82% more likely to develop heart disease, and 27% higher likelihood of death by any cause.
In all of the above studies, it is of note that those who napped for under 30 minutes were at decreased risk of developing diabetes, heart disease, or metabolic syndrome. However, Dr. Yomada believes that additional study is needed to confirm this theory.
Sleep, as many already know, is vital to our health. It is just as important as proper diet and activity. The above studies show that very short naps may be beneficial to our overall health, but the mechanics of how that works in the body and brain are not yet fully understood.
In essence, according to the CDC, one in three Americans do not get enough quality sleep, and the prevalence of disease continues to increase. Further studies that look at how naps correlate to metabolic syndrome, heart disease, and diabetes may help determine better treatment options and strategies for patients suffering with these conditions. Future research will look at how sleep and napping can benefit cardiovascular disease, how longer naps and daytime sleepiness are related to metabolic syndrome, and identify ways healthcare providers can identify health problems based on sleep/napping habits.
Author: Rachael Herman is a professional writer with an extensive background in medical writing, research, and language development. Her hobbies include hiking in the Rockies, fishing, and reading.
© 2021 American Sleep Association.