The effects of statins on cognitive performance are mediated by low-density lipoprotein, C-reactive protein and blood glucose concentrations.

Statins are widely used for cardiovascular disease prevention but their effects on cognition remain unclear. Statins reduce cholesterol concentration and have been suggested to provide both beneficial and detrimental effects. Our aim was to investigate the cross-sectional and longitudinal association between statin use and cognitive performance, and whether blood low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides, glucose, C-Reactive Protein (CRP), and vitamin D biomarkers mediated this association. We used participants from the UK biobank aged 40 to 69 without neurological and psychiatric disorders (n = 147,502 and n = 24,355, respectively). We performed linear regression to evaluate the association between statin use and cognitive performance and, mediation analysis to quantify the total, direct, indirect effects and the proportion meditated by blood biomarkers. Statin use was associated with lower cognitive performance at baseline (β = -0.40 [-0.53, -0.28], P = <.0001) and this association was mediated by LDL (Proportion mediated = 51.4%, P = 0.002), CRP (Proportion mediated = -11%, P = 0.006) and blood glucose (Proportion mediated = 2.6%, P = 0.018) concentrations. However, statin use was not associated with cognitive performance, measured 8 years later (β = -0.003 [-0.11, 0.10], P = 0.96). Our findings suggest that statins are associated with lower short-term cognitive performance by lowering LDL and raising blood glucose concentrations, and better performance by lowering CRP concentrations. In contrast, statins have no effect on long-term cognition and remain beneficial in reducing cardiovascular risk factors.