Four studies using Illumina’s 450k platform were found. Of these, one was previously reviewed [61], and reported as a non-primary outcome a nominal association of two probes with drinking after controlling for smoking. A second found no differences in methylation at CpG sites between groups stratified by alcohol intake, but did find one significant probe when pooling moderate and heavy drinkers versus abstainers, and found further evidence of association with the BLCAP region using an 11-probe sliding window technique [99]. A third study [100] using AD-discordant siblings found 865 hypomethylated and 716 hypermethylated sites, as defined by a DiffScore of 20 or greater (log transformation of P value, corresponding to 0.05 < p < 0.01 according to Illumina materials), with GABRP among the top thirty hypermethylated sites.
