Daytime Napping and Mortality Association in Older Adults

A recent study found an association between longer and more frequent daytime napping and higher mortality risk. The authors suggest using napping frequency and duration as behavioral markers of increased mortality risk [1].

Common activity with a dark side

Daytime napping is a relatively common activity among older adults. It is estimated that between 20% and 60% of older adults take daytime naps [2]. The feeling of reduced fatigue and increased alertness after a brief nap can give the impression that naps have a positive impact, but there is also a dark side to napping, especially excessive napping, which was linked to many adverse health effects in the elderly [3-5].

“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,” said lead author Chenlu Gao, Ph.D., an investigator at the Department of Anesthesiology in Mass General Brigham and an affiliated research fellow at the Division of Sleep and Circadian Disorders in the Department of Medicine.

The authors of this study addressed those shortcomings by analyzing data from wrist actigraphy, which was continuously recorded for up to 14 days. An actigraph is a device that records movement and, when combined with computer algorithms, estimates sleep parameters. While the device may have difficulty distinguishing sleep from quiet wakefulness, the chosen algorithm achieves high accuracy in doing so.

The data came from the Rush Memory and Aging Project (MAP), a study was initiated in 1997 and tracked mortality until 2025. During that time, almost 70% of participants died. That study included 1338 participants aged 56 years or older from retirement communities, senior and subsidized housing, and church groups in northern Illinois.

Duration and frequency matter

Analysis of the obtained data showed that both the duration and frequency of napping, but not variability in duration across days, affected mortality risk. The authors report that longer nap duration and each additional daily nap taken were associated with increased mortality. Specifically, “a 1-hour increase in nap duration corresponded to the risk associated with being approximately 1.1 years older.” While each additional daily nap corresponds to “a risk associated with being approximately 0.6 years older.”

The timing of naps also mattered: people who napped in the morning (between 9 AM and 1 PM) had a higher mortality risk than those who napped in the early afternoon. This risk was “equivalent to being approximately 2.5 years older.” However, in a subsequent analysis examining subgroups more closely, the association was absent when the analysis was limited to cognitively healthy individuals.

Napping at different times of the day might mean different things. While afternoon naps are associated with naturally decreased alertness at that time of day [6] and often linked to local cultural customs such as the siesta, morning naps might indicate disrupted circadian rhythms [7].

Understanding the connection

This study aligns with the results of the previous studies on this topic. For example, a recent meta-analysis showed that taking short naps (less than one hour) wasn’t associated with increased mortality risk, whereas taking longer naps (more than one hour) was [8].

The researchers speculate on the reasons linking napping and mortality risk. One possible reason for daytime naps is an underlying sleep disorder, such as obstructive sleep apnea; however, the researchers exclude this possibility because the models they used accounted for nighttime sleep duration and quality.

Similarly, they speculated that many chronic conditions can cause daytime fatigue, prompting napping. Although the researchers observed the associations even after adjusting for various comorbidities, they suggest that there may be patients with subclinical or undiagnosed conditions not accounted for in the analysis. Such undiagnosed conditions can lead to increased fatigue, napping, and mortality risk. In such a case, excessive napping would be a marker for an underlying health condition, which, if not addressed and treated, can lead to increased mortality risk.

Another possibility is cardiovascular system-related problems. The researchers explain that napping can result from sleep disruption or circadian misalignment, which can also lead to such problems as increased blood pressure [9], which further leads to a pro-inflammatory and pro-atherogenic state, all increasing mortality risk. What’s more, previous studies have shown an association between long daytime naps and cardiovascular risk factors and cardiovascular diseases [10].

Systemic inflammation was also previously linked to daytime napping. Specifically, an observational study found higher levels of inflammatory markers among those who took naps compared to those who didn’t [11], suggesting that chronic inflammation might lead to fatigue and daytime napping. Further studies indicated that the prevalence of inflammatory markers varies across times of day [12], suggesting possible links to distinct underlying conditions.

A better understanding of those connections should be addressed in future studies, but for now, the researchers propose using napping patterns, which can be easily tracked with increasingly popular wearable devices that monitor activity, as biomarkers to identify patients at health risk.

“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,” said Gao.

Correlation not causation

The study authors advise against drawing causal inferences from their results and to understand them in the broader context of aging processes. “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,” said Gao.

Literature

[1] Gao, C., Cai, R., Zheng, X., Gaba, A., Yu, L., Buchman, A. S., Bennett, D. A., Gao, L., Hu, K., & Li, P. (2026). Objectively Measured Daytime Napping Patterns and All-Cause Mortality in Older Adults. JAMA network open, 9(4), e267938.

[2] Zhang, Z., Xiao, X., Ma, W., & Li, J. (2020). Napping in Older Adults: A Review of Current Literature. Current sleep medicine reports, 6(3), 129–135.

[3] Sun, J., Ma, C., Zhao, M., Magnussen, C. G., & Xi, B. (2022). Daytime napping and cardiovascular risk factors, cardiovascular disease, and mortality: A systematic review. Sleep medicine reviews, 65, 101682.

[4] Li, P., Gao, L., Yu, L., Zheng, X., Ulsa, M. C., Yang, H. W., Gaba, A., Yaffe, K., Bennett, D. A., Buchman, A. S., Hu, K., & Leng, Y. (2023). Daytime napping and Alzheimer’s dementia: A potential bidirectional relationship. Alzheimer’s & dementia : the journal of the Alzheimer’s Association, 19(1), 158–168.

[5] Leng, Y., Wainwright, N. W., Cappuccio, F. P., Surtees, P. G., Hayat, S., Luben, R., Brayne, C., & Khaw, K. T. (2014). Daytime napping and the risk of all-cause and cause-specific mortality: a 13-year follow-up of a British population. American journal of epidemiology, 179(9), 1115–1124.

[6] Milner, C. E., & Cote, K. A. (2009). Benefits of napping in healthy adults: impact of nap length, time of day, age, and experience with napping. Journal of sleep research, 18(2), 272–281.

[7] Bonnet M. H. (1986). Performance and sleepiness as a function of frequency and placement of sleep disruption. Psychophysiology, 23(3), 263–271.

[8] Wang, M., Xiang, X., Zhao, Z., Liu, Y., Cao, Y., Guo, W., Hou, L., & Jiang, Q. (2024). Association between self-reported napping and risk of cardiovascular disease and all-cause mortality: A meta-analysis of cohort studies. PloS one, 19(10), e0311266.

[9] Covassin, N., Bukartyk, J., Singh, P., Calvin, A. D., St Louis, E. K., & Somers, V. K. (2021). Effects of Experimental Sleep Restriction on Ambulatory and Sleep Blood Pressure in Healthy Young Adults: A Randomized Crossover Study. Hypertension (Dallas, Tex. : 1979), 78(3), 859–870.

[10] Sun, J., Ma, C., Zhao, M., Magnussen, C. G., & Xi, B. (2022). Daytime napping and cardiovascular risk factors, cardiovascular disease, and mortality: A systematic review. Sleep medicine reviews, 65, 101682.

[11] Leng, Y., Ahmadi-Abhari, S., Wainwright, N. W., Cappuccio, F. P., Surtees, P. G., Luben, R., Brayne, C., & Khaw, K. T. (2014). Daytime napping, sleep duration and serum C reactive protein: a population-based cohort study. BMJ open, 4(11), e006071.

[12] Wright, F., Hammer, M., Paul, S. M., Aouizerat, B. E., Kober, K. M., Conley, Y. P., Cooper, B. A., Dunn, L. B., Levine, J. D., DEramo Melkus, G., & Miaskowski, C. (2017). Inflammatory pathway genes associated with inter-individual variability in the trajectories of morning and evening fatigue in patients receiving chemotherapy. Cytokine, 91, 187–210.