A stronger association was observed for Aβ1–38 with increased risk of dementia among APOE-ε4 carriers (HR for dementia per SD decrease in Aβ1–38, 1.58; 95% CI, 1.01–2.89), whereas for Aβ1–42, this association was observed only among APOE-ε4 noncarriers (HR for dementia per SD decrease in Aβ1–42, 1.47; 95% CI, 1.09–1.99) (Table 4). Here, APOE is linked to dementia.