The risk factors for AD are, among others, age, genetics (APOE-e4), Down syndrome, genetic mutations involving the APP gene and genes for presenilin-1 and presenilin-2, first-degree relative with AD, smoking, midlife obesity, hypertension, high cholesterol levels, diabetes, diet, low physical activity, lower socioeconomic status, and poor sleep quality. This evidence concerns the gene APP and Alzheimer disease.