title: Family history of Alzheimer disease predicts hippocampal atrophy in healthy middle-aged adults.
abstract: OBJECTIVE
  To evaluate the longitudinal influence of family history (FH) of Alzheimer disease (AD) and apolipoprotein E ε4 allele (APOE4) on brain atrophy and cognitive decline over 4 years among asymptomatic middle-aged individuals.
  
  
  METHODS
  Participants were cognitively healthy adults with (FH+) (n = 60) and without (FH-) (n = 48) a FH of AD (mean age at baseline 54 years) enrolled in the Wisconsin Registry for Alzheimer's Prevention. They underwent APOE genotyping, cognitive testing, and an MRI scan at baseline and 4 years later. A covariate-adjusted voxel-based analysis interrogated gray matter (GM) modulated probability maps at the 4-year follow-up visit as a function of FH and APOE4. We also examined the influence of parent of origin on GM atrophy. Parallel analyses investigated the effects of FH and APOE4 on cognitive decline.
  
  
  RESULTS
  Neither FH nor APOE4 had an effect on regional GM or cognition at baseline. Longitudinally, a FH × APOE4 interaction was found in the right posterior hippocampus, which was driven by a significant difference between the FH+ and FH- subjects who were APOE4-. In addition, a significant FH main effect was observed in the left posterior hippocampus. No significant APOE4 main effects were detected. Persons with a maternal history of AD were just as likely as those with a paternal history of AD to experience posterior hippocampal atrophy. There was no longitudinal decline in cognition within the cohort.
  
  
  CONCLUSIONS
  Over a 4-year interval, asymptomatic middle-aged adults with FH of AD exhibit significant atrophy in the posterior hippocampi in the absence of measurable cognitive changes. This result provides further evidence that detectable disease-related neuroanatomic changes do occur early in the AD pathologic cascade.
authors.affiliation: Geriatric Research Education and Clinical Center, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA.
authors.forename: O C
authors.initials: OC
authors.lastname: Okonkwo
authors.forename: G
authors.initials: G
authors.lastname: Xu
authors.forename: N M
authors.initials: NM
authors.lastname: Dowling
authors.forename: B B
authors.initials: BB
authors.lastname: Bendlin
authors.forename: A
authors.initials: A
authors.lastname: Larue
authors.forename: B P
authors.initials: BP
authors.lastname: Hermann
authors.forename: R
authors.initials: R
authors.lastname: Koscik
authors.forename: E
authors.initials: E
authors.lastname: Jonaitis
authors.forename: H A
authors.initials: HA
authors.lastname: Rowley
authors.forename: C M
authors.initials: CM
authors.lastname: Carlsson
authors.forename: S
authors.initials: S
authors.lastname: Asthana
authors.forename: M A
authors.initials: MA
authors.lastname: Sager
authors.forename: S C
authors.initials: SC
authors.lastname: Johnson
mesh_terms: D000544:Alzheimer Disease / Q000235:genetics* / Q000473:pathology* / Q000517:prevention & control; D000704:Analysis of Variance; D053327:Apolipoprotein E4 / Q000235:genetics*; D001284:Atrophy / Q000175:diagnosis; D003071:Cognition; D015331:Cohort Studies; D005220:Fathers; D005260:Female; D005838:Genotype; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008487:Medical History Taking; D008875:Middle Aged; D009035:Mothers; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests
chemical_list: D053327:Apolipoprotein E4