Alzheimer's disease genetic risk score and neuroimaging in the FINGER lifestyle trial

Abstract INTRODUCTION We assessed a genetic risk score for Alzheimer's disease (AD‐GRS) and apolipoprotein E ( APOE4 ) in an exploratory neuroimaging substudy of the FINGER trial. METHODS 1260 at‐risk older individuals without dementia were randomized to multidomain lifestyle intervention or health advice. N = 126 participants underwent magnetic resonance imaging (MRI), and N = 47 positron emission tomography (PET) scans (Pittsburgh Compund B [PiB], Fluorodeoxyglucose) at baseline; N = 107 and N = 38 had repeated 2‐year scans. RESULTS The APOE4 allele, but not AD‐GRS, was associated with baseline lower hippocampus volume (β = −0.27, p = 0.001), greater amyloid deposition (β = 0.48, p = 0.001), 2‐year decline in hippocampus (β = −0.27, p = 0.01), total gray matter volume (β = −0.25, p = 0.01), and cortical thickness (β = −0.28, p = 0.003). In analyses stratified by AD‐GRS (below vs above median), the PiB composite score increased less in intervention versus control in the higher AD‐GRS group (β = −0.60, p = 0.03). DISCUSSION AD‐GRS and APOE4 may have different impacts on potential intervention effects on amyloid, that is, less accumulation in the higher‐risk group (AD‐GRS) versus lower‐risk group ( APOE ). Highlights First study of neuroimaging and AD genetics in a multidomain lifestyle intervention. Possible intervention effect on brain amyloid deposition may rely on genetic risk. AD‐GRS and APOE4 allele may have different impacts on amyloid during intervention.