Sleep disorder serves as 'significant predictor' of incident dementia in patients with TBI

Sleep disorders in both men and women with traumatic brain injury independently correlated with the onset of dementia, according to results of a retrospective cohort study that included than 712,000 adult patients.

Researchers first published the findings in Sleep, the journal of the Sleep Research Society, and presented the study results at the society’s annual meeting, which is being held virtually.

“Our study’s novelty is its confirmation of sleep disorders’ association with incident dementia in both male and female patients, independently of other known dementia risks,” Tatyana Mollayeva, MD, PhD, associate director of the acquired brain injury research lab at the University of Toronto and affiliate scientist at the KITE Research Institute in the University Hospital Network, University of Toronto, said in a press release. “We are also the first to report on the risks that sleep disorders and other factors pose separately for male and female patients with TBI.”

Mollayeva and colleagues sought to analyze the relationship between sleep disorders and risk for dementia in a population-based cohort of adult men and women with TBI. The retrospective cohort study included patients admitted to the ED or acute care hospital with TBI diagnoses between May 2003 and April 2013. The researchers followed all patients through May 2016. The primary exposure was a sleep disorder, while dementia served as the primary outcome; the researchers defined both variables according to the ICD 10th revision diagnosis. Mollayeva and colleagues examined the relationship between sleep disorders and dementia using multivariate Cox proportional hazard modeling, according to the study report.

The analysis included 712,708 patients with TBI of all severities (median age, 44 years; 59% men).

During a median follow-up period of 52 months (interquartile range, 19-86 months), 4.6% of patients (n = 32,834) developed dementia. After controlling for age, sex, income level, injury severity and known comorbidity risks, a diagnosed sleep disorder served as a “significant predictor” of incident dementia (HR = 1.25; 95% CI, 1.146-1.363), according to the study results.

When the researchers stratified the results by sex, they found that the relationship between a sleep disorder and dementia remained significant among both men (HR = 1.255; 95% CI, 1.112-1.415) and women (HR = 1.234; 95% CI, 1.088-1.4).

“Sensitivity analyses on Alzheimer’s disease case definition and using fine and gray competing risk models confirmed the association between sleep disorder and dementia in both sexes,” Mollayeva and colleagues wrote.

The results indicated that screening for sleep disorders should be “part of regular care” for patients with TBI, according to the researchers. They also noted that, because of the “steady” increase in TBI survivors and in life expectancy, undiagnosed sleep disorders could result in “a new cascade” of cognitive deficits independent of TBI.

“The strong links to incidence of dementia in both sexes suggest a need for more targeted sleep disorders risk awareness in patients with TBI,” Mollayeva said in the press release.

Reference:

SLEEP 2021. Sleep disorders are associated with increased dementia risk in patients with traumatic brain injury. Available at: https://www.sleepmeeting.org/sleep-disorders-are-associated-with-increased-dementia-risk-in-patients-with-traumatic-brain-injury/. Accessed June 10, 2021.