title: Statins, cognition, and dementia—systematic review and methodological commentary.
abstract: Firm conclusions about whether mid-life or long-term statin use has an impact on cognitive decline and dementia remain elusive. Here, our objective was to systematically review, synthesize and critique the epidemiological literature that examines the relationship between statin use and cognition, so as to assess the current state of knowledge, identify gaps in our understanding, and make recommendations for future research. We summarize the findings of randomized controlled trials (RCTs) and observational studies, grouped according to study design. We discuss the methods for each, and consider likely sources of bias, such as reverse causation and confounding. Although observational studies that considered statin use at or near the time of dementia diagnosis suggest a protective effect of statins, these findings could be attributable to reverse causation. RCTs and well-conducted observational studies of baseline statin use and subsequent cognition over several years of follow-up do not support a causal preventative effect of late-life statin use on cognitive decline or dementia. Given that much of the human research on statins and cognition in the future will be observational, careful study design and analysis will be essential.
authors: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA.
authors: Melinda C
authors: MC
authors: Power
authors: Department of Internal Medicine, Rush Institute for Healthy Aging, 1653 West Congress Parkway, Chicago, IL 60612, USA.
authors: Jennifer
authors: J
authors: Weuve
authors: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA.
authors: A Richey
authors: AR
authors: Sharrett
authors: Department of Psychiatry, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
authors: Deborah
authors: D
authors: Blacker
authors: Department of Neurology, Johns Hopkins School of Medicine, 733 North Broadway, Baltimore, MD 21205, USA.
authors: Rebecca F
authors: RF
authors: Gottesman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000453:epidemiology / Q000517:prevention & control*; D003704:Dementia / Q000453:epidemiology / Q000517:prevention & control*; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D064887:Observational Studies as Topic; D016032:Randomized Controlled Trials as Topic
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors