alzhub page briefs (5 strongest publishable findings)

Derived from an observational Alzheimer's cohort; no participant-level data. Numbers and caveats trace to alzhub_findings.json. The prevalence hub is only linked where a finding gives rates; no finding here is a population prevalence estimate.

1. How often does mild cognitive impairment turn into dementia?

• One-line claim: About 3 in 10 people with mild cognitive impairment develop dementia within 3 years.
• Three numbers to show:
• Diagnosed with dementia by 12 months: 8.2% (95% CI 6.6-10.1) (n=988)
• by 36 months: 30.2% (27.2-33.4) (n=988)
• by 48 months: 37.7% (34.3-41.3) (n=988)
• Link to topic hubs: conversion, prevalence.
• Caveat to print: This is a research cohort of volunteers seen at memory clinics, so rates are higher than in the general population, and allowing for the timing of clinic visits moves the one-year figure up to about 13%.
• Source: /home/arodrig5/adni_pipeline/out/summary.md

2. What actually predicts dementia in mild cognitive impairment: tests or scans?

• One-line claim: Memory and thinking tests lift dementia-risk prediction far more than scans or spinal-fluid markers.
• Three numbers to show:
• Age/sex/education/APOE4 only (concordance): 0.635 (0.577-0.686) (n=297)
• • cognitive tests: 0.847 (0.812-0.877) (n=297)
• • amyloid PET and glucose PET: 0.863 (0.832-0.890) (n=297)
• Link to topic hubs: cognition, biomarkers, apoe, conversion.
• Caveat to print: Several of the cognitive tests are used by clinicians to decide the dementia diagnosis itself, which flatters their predictive power.
• Source: /home/arodrig5/adni_pipeline/out/cognitive.md

3. Can a blood test stand in for an amyloid PET scan?

• One-line claim: A blood p-tau217 to amyloid-42 ratio tracks amyloid on PET scans (correlation 0.75).
• Three numbers to show:
• Rank correlation, blood p-tau217/amyloid-42 ratio vs amyloid PET: 0.75 (0.66-0.81) (n=113)
• Rank correlation, blood amyloid-42/40 ratio vs amyloid PET (inverse): -0.68 (-0.75 to -0.59) (n=114)
• Benchmark: spinal-fluid amyloid-42/p-tau181 ratio vs amyloid PET (inverse): -0.81 (-0.83 to -0.78) (n=505)
• Link to topic hubs: biomarkers.
• Caveat to print: Only 113 people, one blood-test platform, and people with mild impairment, so it should not be read as how well the test performs for diagnosis in general.
• Source: /home/arodrig5/adni_pipeline/out/correlations.md

4. Even in a small genetic scan, APOE stands out

• One-line claim: In a small genetic scan the only genome-wide hit for Alzheimer's was the APOE gene region.
• Three numbers to show:
• Odds ratio, APOE-region variant, normal vs dementia: 5.4 (n=321)
• p-value: 6.4e-9 (n=321)
• Genome-wide-significant regions, normal vs dementia: 1 (APOE) (n=321)
• Link to topic hubs: apoe.
• Caveat to print: Only a few hundred people, so the odds ratio is inflated by comparing two extreme groups and this scan could not find new genes.
• Source: /mnt/adni/gwas_analysis/top20_CNvAD_m1_agesex_pc10.csv; /mnt/adni/gwas_analysis/lambda_gc.csv

5. Does genetic liability to ADHD predict cognitive decline in older adults?

• One-line claim: Genetic liability to ADHD did not predict memory or thinking scores or their decline in older adults.
• Three numbers to show:
• Smallest corrected p-value, sequenced sample: 0.793 (n=751)
• Smallest corrected p-value, independent array sample: 0.958 (n=391)
• Smallest corrected p-value, pooled: 0.925 (n=1142)
• Link to topic hubs: cognition, apoe.
• Caveat to print: ADHD is not recorded in this cohort, the score captures only a few percent of ADHD liability, European ancestry only, and the second sample is mainly early-enrolled people with limited amyloid data, so the test of an amyloid interaction is weak.
• Source: /mnt/adni/prs_adhd/report.md; /home/arodrig5/adni_pipeline/out/imputed_prs_replication.md