Effect of the Apolipoprotein E Genotype on Cognitive Change During a Multidomain Lifestyle Intervention A Subgroup Analysis of a Randomized Clinical Trial

IMPORTANCE The role of the apolipoprotein E (APOE) epsilon 4 allele as an effect modifier in lifestyle interventions to prevent cognitive impairment is still unclear. OBJECTIVE To examine whether the APOE epsilon 4 allele modifies the previously reported significant cognitive benefits of a multidomain lifestyle intervention (prespecified subgroup analysis). DESIGN, SETTING, AND PARTICIPANTS The Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) was a randomized clinical trial in 6 centers across Finland (screening and randomization performed from September 7, 2009, through November 24, 2011; intervention duration, 2 years). Data analysis was performed from August 1, 2015, to March 31, 2016. The study population was at-risk older individuals from the general population. Inclusion criteria were age of 60 to 77 years; Cardiovascular Risk Factors, Aging, and Dementia risk score of at least 6 points; and cognition at a mean level or slightly lower than expected for age. Individuals with dementia or substantial cognitive impairment and conditions that prevented cooperation or safe engagement in the intervention were excluded. APOE genotype data were available for 1175 of the 1260 participants. INTERVENTIONS Participants were randomly assigned in a 1: 1 ratio to a multidomain intervention group (diet, exercise, cognitive training, and vascular risk management) or a control group (general health advice). Group allocation was not actively disclosed to participants, and outcome assessors were masked to group allocation. MAIN OUTCOMES AND MEASURES Primary outcome was change in cognition measured through a comprehensive neuropsychological test battery. Analysis was based on modified intention to treat (participants with at least 1 postbaseline assessment). RESULTS A total of 1109 participants (mean [SD] age, 69.3 [4.7] years; 514 [46.3%] female) were included in the analysis: 362 APOE epsilon 4 allele carriers (173 intervention and 189