Too Much Sleep May Spell Trouble for Very Old, Especially Those with Cognitive Impairment

October 27, 2020

Both too much and not enough sleep can have negative ramifications for people of all ages. These range from obesity and cardiovascular disease to diabetes mellitus. Now a new study in the October issue of JAMDA suggests that too much sleep is associated with higher mortality in very old adults.

While cognitive impairment contributes to higher mortality is this population, the authors of The Role of Cognitive Impairment, Physical Disability, and Chronic Conditions on the Association of Sleep Duration with All-Cause Mortality Among the Very Old noted that this isn’t the only factor. They said, “A possible explanation is that poor quality of sleep, such as sleep fragmentation, waking after sleep onset, sleep latency, and feelings of fatigue and lethargy after a long sleep may induce sleep extension and decrease resistance to disease.” This, in turn, may lead to increased mortality.

The authors collected sleep data on nearly 20,000 Chinese adults between the ages of 80 and 105 for up to 10 years. They uncovered a relationship between longer periods of sleep (more than 9 hours per night) and mortality, with a significant relationship between longer sleep and cognitive impairment on mortality. However, the risk of mortality didn’t differ much for people with various physical disabilities and chronic conditions.

“These findings suggest that health practitioners and families should be aware of the potential adverse prognosis associated with long sleep,” the authors concluded. While getting a full night’s sleep is important for older adults and can contribute to health and quality of life, poor sleep—whether too much or too little—should be considered a red flag worth reporting to the physician or other practitioner. This is particularly true for older adults with cognitive impairment.

This study was conducted by researchers at the School of Public Health, Tianjin Medical University, Tianjin, P.R. China; Aging Research Center, Department of Neurobiology, Care Sciences and Society, Karolinksa Institute and Stockholm University, Stockholm, Sweden; and Department of Biostatisticians, School of Public Health, Yale University, New Haven, CT.

Click here for more information on the findings above and more details about the study. To contact the researchers or JAMDA editor for an interview, please email





JAMDA is the official journal of AMDA – The Society for Post-Acute and Long-Term Care Medicine. JAMDA publishes peer-reviewed articles including original studies, reviews, clinical experience articles, case reports, and more, on all topics more important to post-acute and long-term care medicine. Visit for more information.

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AMDA – The Society for Post-Acute and Long-Term Care Medicine is the only medical specialty society representing the community of over 50,000 medical directors, physicians, nurse practitioners, physician assistants, and other practitioners working in the various post-acute and long-term care (PALTC) settings. Dedicated to defining and improving quality, we advance our mission through timely professional development, evidence-based clinical guidance, and tireless advocacy on behalf of members, patients, families, and staff. Visit for more information.