Statins and Cognitive Decline in Older Adults with Normal Cognition or Mild Cognitive Impairment

Objectives: To determine the effect of statins on cognitive decline in healthy elderly adults. Design: Longitudinal. Setting: National Institute of Aging network of Alzheimer's Disease Centers. Participants: Research volunteers with normal cognition at baseline evaluated an average 4.1 times over 3.4 years (1,244 statin users, 2,363 nonusers) and with mild cognitive impairment (MCI) at baseline evaluated an average 3.9 times over 2.8 years (763 users, 917 nonusers). Measurements: Cognitive performance was assessed according to 10 neuropsychological indices and the Clinical Dementia Rating Sum of Boxes (CDR-SOB). Repeated-measures analyses adjusted for age, sex, education, comorbidities, and family history of dementia were conducted. Results: Of participants with normal cognition at baseline, statin users performed significantly better across all visits in attention (Trails A) and had significantly slower annual worsening in CDR-SOB scores (P = .006) and slower worsening in Mini-Mental State Examination scores than nonusers (which was not significant after adjusting for multiple comparisons, P = .05). For participants with MCI, statin users performed significantly better across all visits on attention measures (Trail-Making Test Part A), verbal skills (Category Fluency), and executive functioning (Trail-Making Test Part B, Digit Symbol, and Digits Backward), but there were no differences in cognitive decline between users and nonusers. Conclusion: Elderly adults with normal cognition at baseline who used statins had a slower rate of annual worsening in CDR-SOB than nonusers.