KL and Alzheimer disease: In cerebrospinal fluid (CSF), Klotho levels decreased with age and were higher in healthy elderly individuals compared with patients with AD.15 Low plasma Klotho levels have been associated with lower Mini-Mental State Examination (MMSE)16 scores and an increased risk of vascular dementia, but not with late-onset AD.17 No study has so far correlated Klotho levels with the KL-VS haplotype in patients with AD, to our knowledge.