Glucose metabolism in posterior cingulate cortex has supplementary value to predict the progression of cognitively unimpaired to dementia due to Alzheimer's disease: an exploratory study of 18 F-FDG-PET.
Level 3 - non-randomized controlled study
Longitudinal observational cohort study evaluating prognostic imaging biomarkers.
PubMed 37610594 · doi:10.1007/s11357-023-00897-0
What was done
The authors investigated whether glucose metabolism measured by 18F-FDG-PET standard uptake value ratio (SUVR) in the posterior cingulate cortex (PCC) adds prognostic value to CSF biomarkers (Aβ42 and ptau-181). They evaluated the progression of cognitively unimpaired individuals to Alzheimer's disease dementia using Kaplan-Meier survival analyses to calculate hazard ratios (HR) over 5- and 10-year windows, and assessed physiological correlations with Pearson analyses.
What was found
PCC SUVR progressively declined across the Alzheimer's disease continuum. Combining PCC SUVR with CSF Aβ42 increased the hazard ratio for progression from HR = 2.56 to 3.00 at 5 years and from HR = 2.76 to 4.20 at 10 years. Combining PCC SUVR with CSF ptau-181 increased the HR from 2.83 to 3.91 at 5 years and from 2.32 to 4.17 at 10 years. PCC SUVR showed a weak correlation with CSF Aβ42/Aβ40 (r = 0.14, p = 0.02) and correlated with cognitive scale scores (r ranging from -0.407 to 0.383, p < 0.05).
Why it matters
Incorporating posterior cingulate FDG-PET measures alongside traditional amyloid and tau fluid biomarkers may improve the identification of cognitively unimpaired individuals at highest risk of progressing to dementia.
Limits
The abstract does not disclose the sample size, cohort source, demographic details, follow-up duration distribution, or confidence intervals for the reported hazard ratios. As an observational study, unmeasured confounding and lack of independent cohort validation remain potential concerns.
Cited by
- context Low cerebral blood flow, particularly in the hippocampus, parietal lobes, and posterior cingulate gyrus, is the primary brain imaging predictor of Alzheimer's disease.