Approximately 1 in 8 instances of dementia — roughly half a million across the nation — might be associated with sleeplessness.
The recent discoveries, published on December 27th in the Journals of Gerontology: Series A, lend credence to mounting proof that slumber is an adjustable risk element for cognitive decline, much like impaired hearing and elevated blood pressure.
This research does not establish a direct causal link between sleeplessness and dementia for individuals, according to Yuqian Lin, a data analyst at Massachusetts General Hospital in Boston. Instead, she explains, it examines the overall degree to which sleeplessness could contribute to dementia within the general populace.
Lin and her associates examined data from the National Health and Aging Trends Study, also known as NHATS, a long-term survey comprising 5,900 U.S. adults aged 65 and above. Participants indicated whether they faced challenges in initiating sleep, maintaining sleep, or both. Dementia was identified through established research methodologies employing cognitive assessments and feedback from relatives or caretakers.
To gauge the societal impact of sleeplessness, Lin’s team calculated the proportion of dementia cases that could potentially be averted if sleep disruptions linked to insomnia were eliminated. This calculation integrated the prevalence of both insomnia and dementia within the NHATS cohort with relative risk estimates derived from recent extensive meta-analyses connecting sleeplessness to later-life dementia.
Employing this methodology, the research group estimated that insomnia could be responsible for about 12 percent of dementia cases in the United States. “We were quite struck by the significance of the impact,” Lin remarked. She pointed out that this estimation is comparable to population-level figures for hearing loss, which is widely acknowledged as a significant modifiable risk factor for dementia.
The estimated effect differed based on age and gender. The percentage of dementia cases linked to sleeplessness was somewhat greater among females and most pronounced in adults in their late sixties and early seventies — a period when early preventative measures might yield the most substantial benefits.
Nonetheless, some specialists suggest that the findings warrant careful consideration. The relationship between sleep and dementia is intricate and reciprocal, according to Kristen Knutson, a sleep researcher at Northwestern University Feinberg School of Medicine in Chicago, who was not involved in the study.
There are believable biological mechanisms that link poor sleep to brain well-being, Knutson stated, encompassing inflammation, cardiovascular alterations, and inefficient clearing of metabolic waste from the brain. However, sleep difficulties might also serve as an early harbinger of neurodegeneration, making it difficult to disentangle causality.
“I believe we must acknowledge the importance of sleep disruption for brain health,” Knutson asserted. “I think we are progressing, but this study reinforces the evidence in recognizing that sleep disturbances are not merely an inconvenience — they represent a symptom or a cause related to health. We need to do more to comprehend and acknowledge the significance of sleep health, for both cerebral and general well-being.”
This article was produced as part of the Journalists in Aging Fellows Program, organized by The Gerontological Society of America and The Journalists Network on Generations, with the backing of The John A. Hartford Foundation.
