Poor Sleep Patterns May Accelerate Brain Aging in Late Midlife

Poor sleep patterns are associated with advanced brain age in individuals in midlife, according to study results published in Neurology journal.

To determine whether sleep disturbances impact risk for Alzheimer disease (AD) and AD-related dementias, understanding the relationship between sleep and brain health is important. Researchers aimed to study the effect of poor sleep characteristics and their changes among individuals in midlife.  

Eligible participants were enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study and had available sleep characteristics and brain magnetic resonance imaging (MRI) scans. Participants completed a sleep questionnaire at baseline and at 5 years, including information about sleep duration, sleep quality (measured using a 5-point Likert scale), and other sleep characteristics. Participants were categorized into 4 groups based on sleep characteristics: persistent short, persistent long, short to long, long to short sleep durations.

A total of 589 participants (mean age, 40.4; women, 53%; Black, 39%) were included in the study. The majority of participants (69.2%) had 0 to 1 poor sleep characteristic, following by 22% reporting 2 to 3 and 8% reporting more than 3 poor sleep characteristics.

Two or more poor sleep characteristics were associated with the Black race, hypertension and depression symptoms, and lower educational levels.

Compared with participants with 0 to 1 poor sleep characteristics, those with 2 to 3 or 3 or more poor sleep characteristics had 1.9-year (β=1.87; 95% CI, 0.55-3.18) and 3.5-year (β=3.54; 95% CI, 1.53-5.56) older brain age, respectively. Sleep characteristics were also individually examined. Participants who reported vs did not report bad sleep quality (β=1.84; 95% CI, 0.26-3.43); difficulty initiating sleep (β=2.38; 95% CI, 0.75-4.02); difficulty maintaining sleep (β=1.14; 95% CI, 0.03-2.25); and early morning awakening (β=2.45; 95% CI, 0.99-3.90) had older brain age.

In a subanalysis using repeated sleep data (n=566), participants with bad sleep quality (β=2.75; 95% CI, 0.17-5.33); difficulty initiating sleep (β=3.84; 95% CI, 1.77-5.91); difficulty maintaining sleep (β=1.81; 95% CI, 0.45-3.17); early morning awakening (β=3.81; 95% CI 1.83-5.78; and sleepiness (β=2.42; 95% CI, 0.59-4.24) had 2.8-, 3.8-, 1.8-, 3.8-, and 2.4-year older brain age, respectively.

Limitations of the analysis included the possibility of misclassification, as sleep measures were self-reported by participants; lack of generalizability that may have led to an underestimation of the results; and the observational nature of the study, which limited the ability to establish a causal relationship between sleep and brain age.

The researchers concluded, “Poor sleep was associated with advanced brain age in midlife, highlighting the importance of investigating early sleep interventions for preserving brain health.”