title: Sleep apnea, apolipoprotein epsilon 4 allele, and TBI: mechanism for cognitive dysfunction and development of dementia.
abstract: Sleep apnea is prevalent among patients with traumatic brain injuries (TBIs), and initial studies suggest it is associated with cognitive impairments in these patients. Recent studies found that the apolipoprotein epsilon 4 (APOE epsilon 4) allele increases the risk for sleep disordered breathing, particularly sleep apnea. The APOE epsilon 4 allele is associated with cognitive decline and the development of dementia in the general population as well as in patients with TBI. These findings raise the question of whether patients with TBI who are APOE epsilon 4 allele carriers are more vulnerable to the negative effects of sleep apnea on their cognitive functioning. While few treatments are available for cognitive impairment, highly effective treatments are available for sleep apnea. Here we review these different lines of evidence, making a case that the interactive effects of sleep apnea and the APOE epsilon 4 allele represent an important mechanism by which patients with TBI may develop a range of cognitive and neurobehavioral impairments. Increased understanding of the relationships among sleep apnea, the APOE epsilon 4 allele, and cognition could improve our ability to ameliorate one significant source of cognitive impairment and risk for dementia associated with TBI.
authors.affiliation: Sierra-Pacific Mental Illness Research, Education, and Clinical Center (MIRECC), 151-Y, 3801 Miranda Avenue, Palo Alto, CA 94304, USA. roh@stanford.edu
authors.forename: Ruth
authors.initials: R
authors.lastname: O'Hara
authors.forename: Avinoam
authors.initials: A
authors.lastname: Luzon
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Hubbard
authors.forename: Jamie M
authors.initials: JM
authors.lastname: Zeitzer
mesh_terms: D000544:Alzheimer Disease / Q000235:genetics*; D053327:Apolipoprotein E4 / Q000235:genetics*; D001930:Brain Injuries / Q000150:complications / Q000235:genetics*; D003072:Cognition Disorders / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D016017:Odds Ratio; D012307:Risk Factors; D012737:Sex Factors; D012891:Sleep Apnea Syndromes / Q000150:complications / Q000235:genetics*; D014728:Veterans
chemical_list: D053327:Apolipoprotein E4