Longer sleep duration linked to lower brain volume in Hispanic/Latino population

Key takeaways:

• Researchers analyzed sleep and MRI data from 2,334 individuals.
• Increased sleep was associated with smaller brain volume, particularly in those aged 50 years and older.

In a diverse cohort of Hispanic/Latino individuals, longer sleep duration was associated with lower total brain and gray matter volume, according to research published in Alzheimer’s & Dementia.

“Recent work using self-reported sleep data from the National Health and Interview Survey suggests that Hispanics/Latinos, on average, were more likely to report shorter sleep duration compared to whites,” Kevin A. Gonzalez, BS, a researcher and PhD student in the department of neurosciences at the University of California, San Diego, School of Medicine, and colleagues wrote.

Although prior research confirmed associations between sleep duration, dementia and stroke, the body of research contains few studies that have evaluated sleep pattern–related outcomes of brain disease in diverse populations of Hispanics/Latinos.

Researchers analyzed data culled from the SOL-INCA (Study of Latinos-Investigation of Neurocognitive Aging) MRI study, which included 2,334 Hispanic participants aged 35 to 85 years who underwent neuroimaging, cognitive testing and self-reported their daily sleep duration. Primary outcomes for the study were total and regional brain volumes categorized by number of hours slept per night (fewer than 6 hours, 6 to 9 hours, more than 9 hours). Covariates included continuous age at time of MRI, time between MRI visits, sex, education level, ethnic background and continuous BMI.

Results showed that increased sleep was associated with smaller brain volume (β total_brain = 0.05), which was consistently the case in the subpopulation aged 50 years and older after adjusting for mild cognitive impairment status. Data further showed that sleeping more than 9 hours per night was associated with smaller gray matter  (β combined gray = 0.17) and occipital matter volumes (β occipital_gray = 0.18).

“This study reinforces the importance of sleep duration on brain aging, as well as cognitive impairments and physical health,” Alberto Ramos, MD, MS, professor of clinical neurology at the University of Miami Miller School of Medicine, said in a related release. “Sleep studies are particularly important for Hispanics, who have up to four times the risk for Alzheimer’s disease and related dementias, compared with non-Hispanic whites.”

Reference:

• Study Links Sleep Duration with Brain Volume in Older Hispanic Adults. https://news.med.miami.edu/miller-school-study-links-sleep-duration-with-brain-volume-in-older-hispanic-adults/. Published Sept. 29, 2023. Accessed Oct. 4, 2023.