Table 1

Structural (Volumetric MRI) and Functional (Cognitive Testing) Brain Aging Phenotypes

Exam cycle


Phenotypic Trait (Abbreviated Variable Name)

Number of traits

N

Original Cohort (Exam 26)

Offspring Cohort (Exam 7)

Covariates Used to Create Multivariable-Adjusted Residuals


Volumetric Brain MRI*


Total Cerebral Brain Volume (ATCBV)

1

705

Original Cohort & Offspring data are pooled

Age, age-squared, sex, current smoking status, diabetes, systolic blood pressure, anti-hypertensive drugs, atrial fibrillation, EKG-LVH at Offspring examination 7 and Original cohort 26; data from sex-specific regressions pooled.

Frontal Brain volume (AFBV)

1

705

Parietal Brain Volume (APBV)

1

705

Occipital Brain Volume (AOBV)

1

705

Temporal Brain volume (ATBV)

1

705

Hippocampal Volume (AHPV)

1

327

Lateral Ventricular Volume (ALVV)†

1

705

Temporal Horn Volume (LTHBV)†

1

705

White Matter Hyperintensity Volume (BMRIZLWMHVMV) [Age-, sex-specific Z-score of log-normalized white matter hyperintensity volume]

1

705

Current smoking status, diabetes, systolic blood pressure, anti-hypertensive drugs, atrial fibrillation, EKG-LVH at Offspring examination 7 and Original cohort 26; data from sex-specific regressions pooled.


Cognitive Test Performance


Factor 1:Verbal Memory (F1)

1

694

Original cohort and Offspring data are pooled

Birth cohort by decade, education, Framingham Stroke Risk Profile score, plasma homocysteine concentrations (at the 20th Original cohort and the 6th Offspring examinations), apolipoprotein E genotype (ε4 +ve/-ve); data from sex-specific regressions were pooled.

Factor 2:Visual Memory and Organization (F2)

1

694

Factor 3: Measure of attention and executive function-Trails A and B (F3)

1

694

Boston Naming Test (Nam)

1

694

Similarities (Sim)

1

694

Wide-Range Achievement Test (WRAT)

1

694


*All MRI volumes were expressed as a ratio of total intracranial volume (TCV), trait names used in this table correspond to trait names posted at the website; an 'A' preceding the trait name refers to the multivariable adjusted residual.

† Log-normalized values of these traits were used. Website http://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?id=phs000007 webcite.

Seshadri et al. BMC Medical Genetics 2007 8(Suppl 1):S15   doi:10.1186/1471-2350-8-S1-S15

Open Data