Treatment of cardiovascular risk factors to prevent cognitive decline and dementia: a systematic review.
BACKGROUND
Over the last decade, evidence has accumulated that vascular risk factors increase the risk of Alzheimer disease (AD). So far, few randomized controlled trials have focused on lowering the vascular risk profile to prevent or postpone cognitive decline or dementia.


OBJECTIVE
To systematically perform a review of randomized controlled trials (RCTs) evaluating drug treatment effects for cardiovascular risk factors on the incidence of dementia or cognitive decline.


METHODS
RCTs studying the effect of treating hypertension, dyslipidemia, hyperhomocysteinemia, obesity, or diabetes mellitus (DM) on cognitive decline or dementia, with a minimum follow-up of 1 year in elderly populations.


METHODS
Cognitive decline or incident dementia.


RESULTS
In the identified studies, dementia was never the primary outcome. Statins (2 studies) and intensified control of type II DM (1 study) appear to have no effect on prevention of cognitive decline. Studies on treatment of obesity are lacking, and the results of lowering homocysteine (6 studies) are inconclusive. There is some evidence of a preventive effect of antihypertensive medication (6 studies), but results are inconsistent.


CONCLUSIONS
The evidence of a preventive treatment effect aimed at vascular risk factors on cognitive decline and dementia in later life is scarce and mostly based on secondary outcome parameters. Several important sources of bias such as differential dropout may importantly affect interpretation of trial results.
Ligthart
Suzanne A
SA
Department of General Practice, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. s.a.ligthart@amc.nl
Moll van Charante
Eric P
EP
Van Gool
Willem A
WA
Richard
Edo
E
D000368:Aged; D002318:Cardiovascular Diseases / Q000188:drug therapy / Q000517:prevention & control*; D003072:Cognition Disorders / Q000209:etiology / Q000517:prevention & control*; D003704:Dementia / Q000209:etiology / Q000517:prevention & control*; D003920:Diabetes Mellitus / Q000628:therapy; D050171:Dyslipidemias / Q000628:therapy; D006801:Humans; D020138:Hyperhomocysteinemia / Q000628:therapy; D006973:Hypertension / Q000628:therapy; D008875:Middle Aged; D009765:Obesity / Q000628:therapy; D012308:Risk Management; D016896:Treatment Outcome