In the fully adjusted model, significant predictor variables associated with both dementia and/or MCI and cognitive decline included age (p = 0.002), all levels of education (primary, p < 0.001; secondary, p = 0.019; technical, p < 0.001), number of APOE ε4 risk alleles (1 versus 0, p = 0.018; 2 versus 0, p = 0.002) and hypertension (p = 0.018). This evidence concerns the gene APOE and dementia.