Long regular naps linked with higher death risk in older Vietnamese adults

What the researchers did

The study used data from the Longitudinal Study of Ageing and Health in Vietnam, which ran from 2018 to 2023. It included 4,447 older adults living at home. Their average age at the start was about 70.

People reported how they napped. Choices were no nap, or short (under 30 minutes), medium (30 to 59 minutes) or long (60 minutes or more) naps. Each of these was either taken regularly or only as needed. The researchers also scored night-time sleep health on four things: satisfaction with sleep, daytime sleepiness, broken sleep and sleep duration.

They then checked who had died by the four-year follow-up. They tested whether nap type was linked with death. They also tested whether this link depended on how well people slept at night.

What they found

By follow-up, 514 people (12%) had died. After allowing for night-time sleep health and other factors, only regular long naps were linked with a higher chance of dying. The odds were about 40% higher than for people who did not nap. Other nap types did not differ clearly from no napping.

Night-time sleep health seemed to matter too. Taking long naps only when needed, combined with poor night-time sleep, was linked with higher death odds. For most nap types, the chance of dying rose as night-time sleep got worse. The exceptions were regular long naps, where it stayed high whatever the night-time sleep, and regular short naps, where it fell as night-time sleep got worse.

The authors concluded that regular long naps were linked with higher death risk, and that napping and night-time sleep may be tied together.

The caveats

• This was an observational study, so it cannot show that long naps cause earlier death. People may nap for an hour or more because they are already unwell or very tired.
• Napping and sleep were self-reported. The abstract does not say whether illness, such as sleep apnoea, was taken into account.
• Naps were recorded at the start of the study only, and follow-up was about four years.
• Seven nap types were compared, so some groups may have been small. The results come from older adults in Vietnam and may not apply to other countries or younger people.

What this could mean for you

If you nap, this study does not suggest that short naps, or naps taken only when needed, were linked with higher death risk. Regular naps of an hour or more were linked with higher odds of dying, but the study cannot say that napping caused this.

If you find you need long naps every day, or feel very sleepy in the daytime, it is worth mentioning to your doctor. It can be a sign of poor night-time sleep or another health problem that can be treated.

Night-time sleep health was also linked with outcomes in this study, so looking at the whole 24-hour pattern may help more than looking at naps alone.