Friday, September 4, 2020

Wake up!

Long Napping Increases Risk of Cardiovascular Disease, Study Finds

Cat Kitten GIFNapping is a habit prevalent worldwide and occurs from an early age.

Hypothetically, a daytime nap might reduce stress and be recognized as a public health tool to battle fatigue.

Maintaining a healthy nap habit has been considered as an important lifestyle factor for one’s health. 

However, nap duration can range from minutes to over one hour and it is indeed not the same when it comes to the frequency, which could cause heterogeneity among individuals.

Several observational studies were previously conducted to investigate whether the duration of napping affects potential health consequences.

However, the association between napping and the risk of incident cardiovascular disease and all-cause mortality was unclear. Additionally, the dose-response relation between nap time and relevant health outcomes was also uncertain.

“Daytime napping is common all over the world and is generally considered a healthy habit,” said lead author Dr. Zhe Pan, a researcher in the First Affiliated Hospital of Guangzhou Medical University.

“A common view is that napping improves performance and counteracts the negative consequences of ‘sleep debt.’ Our study challenges these widely held opinions.”

Dr. Pan and colleagues conducted a systematic search of Medline, Embase, and Cochrane databases from inception to December 2019 for cohort studies investigating the association between napping and the risk of incident cardiovascular disease and/or all-cause mortality.

They included a total of 313,651 participants (57.8% female, 38.9% took naps) from 20 cohort studies in their analysis.

They found that long naps (more than one hour) were associated with a 30% greater risk of all-cause death and 34% higher likelihood of cardiovascular disease compared to no napping.

When night-time sleep was taken into account, long naps were linked with an elevated risk of death only in those who slept more than 6 hours per night.

Overall, naps of any length were linked with a 19% elevated risk of death.

The connection was more pronounced in women, who had a 22% greater likelihood of death with napping compared to no napping, and older participants, whose risk rose by 17% with naps.

Short naps (less than one hour) were not risky for developing cardiovascular disease.

“The results suggest that shorter naps (especially those less than 30 to 45 minutes) might improve heart health in people who sleep insufficiently at night,” Dr. Pan said.

“The reasons why napping affects the body are still uncertain, but some studies have suggested that long snoozes are linked with higher levels of inflammation, which is risky for heart health and longevity.”

“Other research has connected napping with high blood pressure, diabetes, and poor overall physical health.”

“If you want to take a siesta, our study indicates it’s safest to keep it under an hour. For those of us not in the habit of a daytime slumber, there is no convincing evidence to start.”

The study was published in the journal Sleep Medicine.
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Zhe Pan et al. 2020. Association of napping and all-cause mortality and incident cardiovascular diseases: a dose-response meta analysis of cohort studies. Sleep Medicine 74: 165-172; doi: 10.1016/j.sleep.2020.08.009