Daytime sleepiness is a warning sign
Christiane Fux studied journalism and psychology in Hamburg. The experienced medical editor has been writing magazine articles, news and factual texts on all conceivable health topics since 2001. In addition to her work for, Christiane Fux is also active in prose. Her first crime novel was published in 2012, and she also writes, designs and publishes her own crime plays.
More posts by Christiane Fux All content is checked by medical journalists.Anyone who has a pronounced need for sleep during the day should pay particular attention to their heart. Because daytime sleepiness increases the likelihood of developing a so-called metabolic syndrome. Its four characteristics: obesity, especially in the middle of the body, high blood pressure, increased blood sugar levels and impaired lipid metabolism.
Doctors also refer to this combination as “a deadly quartet” because it increases the risk of diabetes, diseased blood vessels, heart attacks and strokes to a particularly high degree. Researchers led by Tomohide Yamada from the University of Tokyo have now found that people who complain of extreme tiredness during the day or who sleep extensively during the day develop a metabolic syndrome particularly often.
Only a long nap is questionable
At first glance, the result seems surprising. Because an afternoon nap is considered performance-enhancing and healthy. A closer look at the data then also shows a U-shaped curve for the risk of a metabolic or heart disease. Only those who slept for more than 40 minutes were prone to unfavorable metabolic changes. If you took a nap but didn't sleep for more than 30 minutes, the risk of the fatal quartet even decreased.
For the overview study, the Japanese researchers evaluated 21 studies with more than 300,000 men and women from Asia and various Western countries. The participants answered questions about their sleeping habits and how tired they were during the day. They were also asked about their current health and medical history.
A day's sleep of 90 minutes and more was associated with a 50 percent higher risk of metabolic syndrome. The greatest increase was the risk of cardiovascular diseases. Just one hour of sleep a day caused it to climb by 83 percent, and that for diabetes by as much as 43 percent.
Fatigue warning signs
It cannot be deduced from the data that it is sleep during the day that makes you sick. It seems more likely that an already troubled metabolism is associated with fatigue. It also fits in with the fact that participants who did not enjoy a siesta but felt very tired were also more likely to get sick.
It is not new that sleep and cardiovascular diseases, obesity and diabetes are linked. However, previous studies had particularly focused on nighttime sleep. They showed that those who sleep too little (less than six hours) are at a higher risk of diabetes, cardiovascular diseases and obesity. The same also applies to people who sleep particularly long night after night - that is, nine hours and more.
Sleep, exercise, nutrition
"Sleep is an essential part of a healthy lifestyle - just like diet and exercise," says Yamada. The biological mechanisms through which sleep and health are interlinked, however, still needs to be researched.
Further studies should clarify the possible positive effect of short naps as well as the connection between long sleep periods during the day, daytime sleepiness and metabolic syndrome. A person's sleeping habits could also provide clues to future health problems. (cf)
Source. "Long Naps, Daytime Sleepiness Tied to Greater Risk of Metabolic Syndrome," American College of Cardiology News Release, March 21, 2016
