A 19-year study reveals that objectively measured nap length, frequency, and timing can serve as trackable warning signs for underlying health conditions.
Key takeaways:
- Investigators followed 1,338 older adults for up to 19 years using wrist activity monitors to map nap length, frequency, time of day, and day-to-day variability.
- Each additional hour of daytime napping per day was associated with a 13% higher mortality risk, while each extra nap carried a 7% higher risk.
- Morning nappers demonstrated a 30% higher mortality risk compared to afternoon nappers.
- Researchers suggest implementing wearable daytime nap assessments to predict health conditions and prevent further decline
New research reveals that as people age, naps may be an easily trackable warning sign of underlying conditions or declining health. A study by investigators from Mass General Brigham and Rush University Medical Center followed 1,338 older adults for up to 19 years to track napping habits and associated mortality rates. They found longer, more frequent, and morning naps were associated with higher mortality rates.
The results are published in JAMA Network Open.
Between 20% and 60% of older adults take naps. While infrequent napping can be restorative, excessive daytime napping in old age has been linked to a wide range of health issues. Despite these associations, the relationship between napping and health in older individuals has been understudied, and previous research often lacked objective napping pattern data, the time of day naps took place, and changes in napping patterns from day to day.
“Excessive napping later in life has been linked to neurodegeneration, cardiovascular diseases and even greater morbidity, but many of those findings rely on self-reported napping habits and leave out metrics like when and how regular those naps are,” says lead author Chenlu Gao, PhD, an investigator in the department of anesthesiology at Mass General Brigham and an affiliated research fellow in the division of sleep and circadian disorders in the department of medicine, in a release. “Our study is one of the first to show an association between objectively measured nap patterns and mortality and suggests there is immense clinical value in tracking napping patterns to catch health conditions early.”
To close this knowledge gap, researchers turned to data from the Rush Memory and Aging Project. Beginning in 2005, participants wore wrist activity monitors for 10 days to measure rest-activity data. The team extracted sleep patterns from the data and mapped nap length, frequency, time of day, and day-to-day variability.
By 2025, 19 years’ worth of data had been collected. The researchers analyzed the data for associations between napping patterns at the initial assessment and all-cause mortality during the follow-up period.
They found that each additional hour of daytime napping per day was associated with an approximately 13% higher mortality risk, and each extra nap per day was associated with an approximately 7% higher mortality risk. Additionally, morning nappers had a 30% higher mortality risk compared to afternoon nappers. Irregular napping patterns were not associated with any increased mortality risk.
“It is important to note that this is correlation not causation. Excessive napping is likely indicating underlying disease, chronic conditions, sleep disturbances, or circadian dysregulation,” says Gao in a release. “Now that we know there is a strong correlation between napping patterns and mortality rates, we can make the case to implement wearable daytime nap assessments to predict health conditions and prevent further decline.”
