Possession of an APOE-ε4 allele, compared to APOE-e3 allele homozygotes, resulted in a 3.28 fold increased risk for AD (95% CI 1.98–5.44), whereas being regularly physically active (vs. not regularly physically active) reduced the risk for AD (OR 0.69, 95% CI 0.50–0.96). Here, APOE is linked to Alzheimer disease.