Correlations between apolipoprotein E epsilon4 gene dose and brain-imaging measurements of regional hypometabolism.
Level 4 - case-series / case-control
Cross-sectional matched observational neuroimaging study
PubMed 15932949 · doi:10.1073/pnas.0500579102
What was done
Positron emission tomography (PET) was used to measure the cerebral metabolic rate for glucose (CMRgl) in 160 cognitively normal individuals aged 47 to 68 years. The cohort included 36 APOE epsilon4 homozygotes, 46 heterozygotes, and 78 noncarriers matched for gender, age, and educational level. Brain regions evaluated included the precuneus, posterior cingulate, parietotemporal, and frontal cortex.
What was found
The abstract reports no numerical values, correlation coefficients, or p-values. It states that APOE epsilon4 gene dose was correlated with lower CMRgl in the precuneus, posterior cingulate, parietotemporal, and frontal cortex.
Why it matters
This study shows a gene-dose link between the APOE epsilon4 allele and regional brain hypometabolism in cognitively intact adults. It suggests PET imaging could serve as a quantitative presymptomatic endophenotype to evaluate modifiers of Alzheimer's risk.
Limits
The study is cross-sectional and cannot determine rate of cognitive decline or individual conversion to dementia. The abstract reports no numerical effect sizes or variance data. The sample is restricted to adults aged 47 to 68.
Cited by
- supports Brain metabolic changes detectable by fluorodeoxyglucose (FDG) PET occur in people's 30s and 40s, preceding Alzheimer's cognitive symptoms by two to three decades.