Mean DNA methylation levels over − 105, − 101, − 99, and − 94 CpG sites of the p62 gene were decreased in SDB patients with cognitive dysfunction versus those without cognitive dysfunction (3.56 ± 0.99 versus 4.01 ± 0.83%, adjusted p = 0.015, Fig. 3I). This evidence concerns the gene SQSTM1 and sleep apnea syndrome.