Indeed, hyponatremia was consistently associated with an increased risk of dementia in several observational studies and the mechanisms mediating the effect may include the chronic activation of the renin-angiotensin system, inflammation, oxidative stress, and mitochondria and hippocampal dysfunctions (Renneboog et al., 2006; Cooper et al., 2015; Xu et al., 2015; Chung et al., 2017). This evidence concerns the gene REN and dementia.