HealthDay News — Sleep-disordered breathing is associated with cognitive deficits, with the strongest associations seen in apolipoprotein ε-4 (APOE-ε4) allele carriers, according to a study published in the Annals of the American Thoracic Society.
Dayna S. Johnson, PhD, MPH, from Brigham and Women’s Hospital in Boston, and colleagues examined the correlations between indicators of sleep-disordered breathing and cognitive function among 1752 participants in the Multi-Ethnic Study of Atherosclerosis, and assessed effect modification by the APOE-ε4 allele.
About 9.7% of participants had sleep apnea syndrome (SAS) and 26.8% had one or more copies of the APOE-ε4 allele. The researchers found that a 1 standard deviation increase in the percent sleep time with up to 90% oxyhemoglobin saturation (%Sat<90%) and Epworth Sleepiness Scale (ESS) score correlated with poorer attention and memory, as measured by the Digit Span Test (DST) forward score.
There was also a correlation for SAS and higher ESS scores with poorer attention and processing speed, as measured by the Digit Symbol Coding Test (DSCT). The correlation of %Sat<90% with DST forward and of ESS with DSCT was modified by the presence of the APOE-ε4 allele.
“Overnight hypoxemia and sleepiness were associated with cognition. The average effect estimates were small, similar to effects estimated for several other individual dementia risk factors,” the authors wrote. “Associations were strongest in APOE-ε4 risk allele carriers.”
Johnson DA, Lane J, Wang R, et al. Greater cognitive deficits with sleep-disordered breathing among individuals with genetic susceptibility to Alzheimer’s disease: The multi-ethnic study of atherosclerosis [published online July 21, 2017]. Ann Am Thorac Soc. doi:10.1513/AnnalsATS.201701-052OC