Cholesterol and cognitive performance in normal controls and the influence of elective statin use after conversion to mild cognitive impairment: results in a clinical trial cohort.
BACKGROUND
We reported a significant 67% reduction in the hazard risk of incident Alzheimer's disease (AD) with elective statin use in the AD Anti-inflammatory Prevention Trial (ADAPT), without a reduction in risk of incident mild cognitive impairment (MCI).


OBJECTIVE
To assess if cholesterol levels are associated with cognitive performance and determine if statin use alters cognitive performance after onset of MCI.


METHODS
Fractionated cholesterol levels, neurological and cognitive status were evaluated annually. Comparisons of non-LLA (lipid-lowering agent) users or statin-LLA users were performed blind to the ADAPT medication randomization. Pearson's correlations were validated using a time-dependent linear mixed model.


RESULTS
The MMSE performance significantly declined over time in non-LLA users, and, after adjusting for this, a significant positive correlation between MMSE and HDL was identified (p = 0.0002). A negative correlation between total and LDL cholesterol, and immediate and delayed recall of the Rivermead paragraph was significant (total cholesterol, p < 0.003; LDL, p < 0.02). Pilot data suggest a positive signal on delayed recall of both the Hopkins word list and Rivermead paragraph with deterioration in the non-LLA users and improvement in the statin users after conversion to MCI.


CONCLUSIONS
Cholesterol levels may be associated with differential performance on the MMSE and measures of learning or memory. The trend for improved delayed recall in statin users with MCI compared to non-LLA users with MCI may have contributed to the reduced hazards risk of incident AD without reducing the risk of MCI.
Roberts Laboratory for Neurodegenerative Disease Research, Sun Health Research Institute, Sun City, Ariz., USA. alina.solomon@uku.fi
D Larry
DL
Sparks
Richard J
RJ
Kryscio
Donald J
DJ
Connor
Marwan N
MN
Sabbagh
Lisa M
LM
Sparks
Yushun
Y
Lin
Carolyn
C
Liebsack
D000544:Alzheimer Disease / Q000517:prevention & control*; D002784:Cholesterol / Q000378:metabolism; D003072:Cognition Disorders / Q000188:drug therapy*; D015331:Cohort Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D000960:Hypolipidemic Agents / Q000627:therapeutic use*; D008297:Male; D008609:Mental Status Schedule; D009483:Neuropsychological Tests; D013223:Statistics as Topic
D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D000960:Hypolipidemic Agents; D002784:Cholesterol