Poor Sleep Associated With Long-Term Cognitive Decline in Hispanic/Latinx

According to research led by University of Miami Miller School of Medicine neurology faculty, poor sleep is associated with the risk of long-term cognitive decline in Hispanic/Latinx adults. 

A paper published online on May 25, 2021 in Alzheimer & Dementia reported the risk was especially high in middle-age adults without metabolic syndrome and women without obesity or metabolic syndrome. Hispanics/Latinx individuals were more likely to develop cognitive decline in processing speed, mental flexibility, and verbal memory during a 7-year follow up study. The study involved individuals who had sleep disordered breathing (eg, obstructive sleep apnea) and long sleep duration of 9 or more hours. 

“A surprising finding of this study of 5,500 US Hispanic/Latinx adults was that participants without obesity that had sleep apnea and long sleep duration had worse cognitive decline,” said senior author Alberto Ramos, MD, MSPH, associate professor of neurology, and research director of the Sleep Disorders Program. “To some extent, this was like a natural experiment where we removed the effect that obesity has on cognition and saw ‘the pure effect’ of sleep difficulties, such as sleep apnea, and long sleep duration on cognitive health.” 

According to Sonya Kaur, PhD, instructor in the Division of Neuropsychology at the Miller School, the study shows that metabolic risk factors for neurocognitive decline in nonHispanic/Latinx individuals are not generalizable to Hispanic/Latinx individual. Compared with nonHispanic/Latinx white individuals, Hispanic/Latinx people are at greater risk for metabolic syndrome and 4 times as likely to develop Alzheimer disease (AD).  

“In general, the relationship between sleep and cognition was not mediated by metabolic syndrome and obesity in Hispanic/Latinx people as it is in other groups,” Dr. Kaur said. “For Hispanic/Latinx persons, sleep seems to be a much stronger predictor than obesity and metabolic syndrome, which are traditionally thought of as predictors in terms of what causes cognitive decline in nonHispanic/Latinx people.” 

“We are conducting ongoing research on the cognitive effects of migration factors and genetic risk factors in Hispanic/Latinx patients, because there is evidence that genetic risk factors in nonHispanic/Latinx white individuals do not predict cognition decline in the same way as in Hispanic/Latinx people,” Dr. Kaur said. 

Dr. Ramos and colleagues previously published data about high prevalence of sleep disorders associated with neurocognitive dysfunction, including memory decline, in a diverse population of Hispanic/Latinx individuals.