2022 Alzheimer's Association Research Fellowship to Promote Diversity (AARF-D)

Timing and Irregularity of Daytime Napping and Alzheimer’s disease

What factors affect how daytime napping impacts cognitive health?

Chenlu Gao, Ph.D.
Brigham and Women's Hospital
Boston, MA - United States

Background

Circadian rhythms are natural biological changes that occur over an approximately twenty-four-hour cycle and are often called the sleep-wake cycle. These rhythms usually respond to the amount of light and darkness in an environment. They involve daily patterns of sleeping, eating and other activities. Disruptions to circadian rhythms can alter an individual's  ability to get proper sleep. Recent studies reveal that sleep disruption or poor sleep patterns may impact the risk of developing Alzheimer’s and other brain diseases and may precede cognitive impairment by several years. 

Daytime napping, which is prevalent among older adults, is a critical component of the sleep-wake cycle. However, the impact of daytime napping on cognitive health is not well understood. While some studies suggest that daytime napping may benefit cognitive functioning, others have found that longer naps are associated with faster cognitive decline as an individual ages. Factors such as the timing and regularity of naps may be important aspects of a person’s napping behavior, yet little research has examined their impact.
 

Research Plan

Dr. Chenlu Gao and colleagues will study the relationship between timing and regularity of daytime napping, cognitive functioning, and development of Alzheimer’s. The researchers will study 1,400 older adults in the Memory and Aging Project, a community-based study led by Rush Alzheimer’s Disease Center. In the study participants, the study team will objectively measure sleep/wake states using wristband actigraphy, a non-invasive method of recording human sleep-wake cycles, and identify daytime napping schedule and duration. The team will also administer a battery of cognitive tests to the participants on an annual basis. 

In addition, Dr. Gao and colleagues will study whether the timing and consistency of daytime naps interact with specific genetic risk factors for Alzheimer’s to influence the trajectory of cognitive changes over time.
 

Impact

This study may shed light on the links between daytime napping, genetic susceptibility, and Alzheimer’s in older adults. The findings may help establish clinical guidelines on healthy napping, as well as help caregivers establish daily caregiving routines for older adults.