Thus, G. Tranah et al., based on the results of the Osteoporotic Fractures in Men (MrOS) Study, found that, in subjects with cognitive decline apolipoprotein E (APOE), ε4 genotype carriers (APOE rs429358 SNP) had longer stage 3 NREM-sleep, lower WASO, and higher sleep efficiency (reflecting lower arousability), which the authors explained by the imbalance in neural plasticity and an overactive downscaling of synapses during sleep [37]. Here, APOE is linked to Mental deterioration.