## Results: 3

1.

(A) Meta-analysis of studies testing the association between

*APOE ε*4+ and cerebral microbleeds (CMB). Fixed-effects inverse variance–weighted meta-analysis (heterogeneity test:*I*² = 0%,*p*= 0.88); secondary meta-analysis in the general population (heterogeneity test:*I*² = 0%,*p*= 0.45) and in high-risk population (heterogeneity test:*I*² = 0%,*p*= 0.96) also using a fixed-effects inverse variance–weighted meta-analysis. For secondary analysis using a random-effects model, see figure e-7. (B) Meta-analysis of studies testing the association between*APOE ε*44 and CMB. Fixed-effects inverse variance–weighted meta-analysis (heterogeneity test:*I*² = 11%,*p*= 0.34). For secondary analysis using a random-effects model, see figure e-7.*APOE ε*4+ =*APOE ε*4 carrier status; FHS = Framingham Heart Study; OR = odds ratio.2.

(A) Meta-analysis of studies testing the association between

*APOE ε*2+ and white matter hyperintensities (WMH) burden. Fixed-effects inverse variance–weighted meta-analysis for studies on*APOE ε*2+ and continuous WMH (providing standardized mean differences) (heterogeneity test:*I*² = 41%,*p*= 0.17) (i); all studies are from the general population. Fixed-effects inverse variance–weighted meta-analysis for*APOE ε*2+ and dichotomized WMH (heterogeneity test:*I*² = 45%,*p*= 0.14) (ii). For secondary analysis using a random-effects model, see figure e-8. (B) Meta-analysis of studies testing the association between*APOE ε*2+ and brain infarcts (BI). Fixed-effects inverse variance–weighted meta-analysis (heterogeneity test:*I*² = 25%,*p*= 0.26). For secondary analysis using random-effects model, see figure e-9.*APOE ε*2+ =*APOE ε*2 carrier status; FHS = Framingham Heart Study; OR = odds ratio;*p*=*p*value from inverse variance–weighted meta-analysis;*p z*score =*p*value from sample size–weighted*z*score–based meta-analysis; SMD = standardized mean difference; Sydney MAS = Sydney Memory and Ageing Study.3.

(A) Meta-analysis of studies testing the association between

*APOE ε*4+ and white matter hyperintensities (WMH) burden: fixed-effects inverse variance–weighted meta-analysis for studies on*APOE ε*4+ and continuous WMH (providing standardized mean differences) (heterogeneity test:*I*² = 24%,*p*= 0.20) (i); secondary meta-analyses in the general population (heterogeneity test:*I*² = 39%,*p*= 0.11) and in high-risk populations (heterogeneity test:*I*² = 0%,*p*= 0.63) also using a fixed-effects inverse variance–weighted meta-analysis. Fixed-effects inverse variance–weighted meta-analysis for*APOE ε*4+ and dichotomized WMH (heterogeneity test:*I*² = 0%,*p*= 0.65) (ii); secondary meta-analyses in the general population (heterogeneity test:*I*² = 0%,*p*= 0.46) and in high-risk populations (heterogeneity test:*I*² = 0%,*p*= 0.74) also using a fixed-effects inverse variance–weighted meta-analysis. Secondary analyses using random-effects meta-analyses yielded similar results (figure e-4). Additive model: additive genetic model relating the number of copies of the ε4 allele to WMH volume. (B) Meta-analysis of studies testing the association between*APOE ε*44 and WMH burden. Fixed-effects inverse variance–weighted meta-analysis on WMH burden studied as a continuous (heterogeneity test:*I*² = 8%,*p*= 0.36) (i) and as a dichotomous variable (heterogeneity test:*I*² = 0%,*p*= 0.93) (ii). For secondary analyses using a random-effects model, see figure e-5.*APOE ε*4+ =*APOE ε*4 carrier status; FHS = Framingham Heart Study; HTN = hypertension; OR = odds ratio;*p = p*value from inverse variance–weighted meta-analysis;*p z*score =*p*value from sample size–weighted*z*score–based meta-analysis; SMD = standardized mean deviation; Sydney MAS = Sydney Memory and Ageing Study.