title: Brain white matter damage in aging and cognitive ability in youth and older age.
abstract: Cerebral white matter hyperintensities (WMH) reflect accumulating white matter damage with aging and impair cognition. The role of childhood intelligence is rarely considered in associations between cognitive impairment and WMH. We studied community-dwelling older people all born in 1936, in whom IQ had been assessed at age 11 years. We assessed medical histories, current cognitive ability and quantified WMH on MR imaging. Among 634 participants, mean age 72.7 (SD 0.7), age 11 IQ was the strongest predictor of late life cognitive ability. After accounting for age 11 IQ, greater WMH load was significantly associated with lower late life general cognitive ability (β = -0.14, p < 0.01) and processing speed (β = -0.19, p < 0.001). WMH were also associated independently with lower age 11 IQ (β = -0.08, p < 0.05) and hypertension. In conclusion, having more WMH is significantly associated with lower cognitive ability, after accounting for prior ability, age 11IQ. Early-life IQ also influenced WMH in later life. Determining how lower IQ in youth leads to increasing brain damage with aging is important for future successful cognitive aging.
authors.affiliation: Brain Research Imaging Centre, Department of Clinical Neurosciences, University of Edinburgh, Edinburgh, UK; Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, UK.
authors.forename: Maria Del C
authors.initials: Mdel C
authors.lastname: Valdés Hernández
authors.forename: Tom
authors.initials: T
authors.lastname: Booth
authors.forename: Catherine
authors.initials: C
authors.lastname: Murray
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Gow
authors.forename: Lars
authors.initials: L
authors.lastname: Penke
authors.forename: Zoe
authors.initials: Z
authors.lastname: Morris
authors.forename: Susana Muñoz
authors.initials: SM
authors.lastname: Maniega
authors.forename: Natalie A
authors.initials: NA
authors.lastname: Royle
authors.forename: Benjamin S
authors.initials: BS
authors.lastname: Aribisala
authors.forename: Mark E
authors.initials: ME
authors.lastname: Bastin
authors.forename: John M
authors.initials: JM
authors.lastname: Starr
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Deary
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Wardlaw
mesh_terms: D000368:Aged; D000375:Aging / Q000473:pathology* / Q000502:physiology / Q000523:psychology*; D002540:Cerebral Cortex / Q000473:pathology* / Q000503:physiopathology*; D002648:Child; D003071:Cognition; D003072:Cognition Disorders / Q000209:etiology* / Q000473:pathology* / Q000523:psychology; D005260:Female; D006801:Humans; D007361:Intelligence Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D002666:Psychology, Child; D012307:Risk Factors
keywords: Cerebrovascular disease/stroke; Cognition; Cognitive aging; Dementia; MRI; White matter hyperintensities