Higher Visit-to-Visit Low-Density Lipoprotein Cholesterol Variability Is Associated With Lower Cognitive Performance, Lower Cerebral Blood Flow, and Greater White Matter Hyperintensity Load in Older Subjects

Background: Recently, it was shown that intraindividual variation in low-density lipoprotein cholesterol (LDL-C) predicts both cerebrovascular and cardiovascular events. We aimed to examine whether this extends to cognitive function and examined possible pathways using a magnetic resonance imaging substudy.

Methods: We investigated the association between LDL-C variability and 4 cognitive domains at month 30 in 4428 participants of PROSPER (PROspective Study of Pravastatin in the Elderly at Risk). Additionally, we assessed the association of LDL-C variability with neuroimaging outcomes in a subset of 535 participants. LDL-C variability was defined as the intraindividual standard deviation over 4 postbaseline LDL-C measurements, and all analyses were adjusted for mean LDL-C levels and cardiovascular risk factors.

Results: Higher LDL-C variability was associated with lower cognitive function in both the placebo and pravastatin treatment arms. Associations were present for selective attention (P=0.017 and P=0.11, respectively), processing speed (P=0.20 and P=0.029), and memory (immediate recall, P=0.002 and P=0.006; delayed recall, P=0.001 and P≤0.001). Furthermore, higher LDL-C variability was associated with lower cerebral blood flow in both trial arms (P=0.031 and P=0.050) and with greater white matter hyperintensity load in the pravastatin arm (P=0.046). No evidence was found for interaction between LDL-C variability and pravastatin treatment for both cognitive and magnetic resonance imaging outcomes.

Conclusions: We found that higher visit-to-visit variability in LDL-C, independently of mean LDL-C levels and statin treatment, is associated with lower cognitive performance, lower cerebral blood flow, and greater white matter hyperintensity load.