APOE and dementia: A notable result is the pronounced sex difference in dementia risk associated with the APOE ε4 allele, with women facing a substantially higher risk in those with two copies of APOE ε4 allele (HR = 4.39, 95% CI: 3.52–5.47) than men (HR = 2.92, 95% CI: 2.20–3.88).