Longitudinal association of remnant cholesterol with cognitive decline vary by lipid-lowering therapy: a population-based cohort study

ObjectiveAlthough the association between remnant cholesterol (RC) and cognitive impairment has been reported, the association of RC with cognitive decline remains scarce. Also, the role of lipid- lowering therapy in the association is unclear. The study aimed to examine the longitudinal associations of RC with cognitive decline by lipid-lowering drug use status. MethodsThe study utilized data from wave 2 (2004-2005) to wave 8 (2016-2017) of the English Longitudinal Study of Ageing (ELSA). Global cognitive functions at baseline (wave 2) and during the follow-up (waves 3-8) were assessed by integrating three cognitive domains, including memory capacity, semantic fluency, and orientation. Multivariate-adjusted linear mixed models were employed to examine the longitudinal associations, with results presented as {beta} [95% confidence interval (CI)] in standard deviation (SD)/year. ResultsOf the 5053 participants ultimately included, 55.4% were female and the mean age (SD) was 65.7 (9.3) years. Per 1 mmol/L increment in RC was significantly associated with a faster rate of cognitive decline ({beta} = -0.010 SD/year, 95% CI: -0.019, -0.001). Furthermore, we observed that the association pattern between RC and cognitive decline only in the non-lipid-lowering drug group ({beta} = -0.019 SD/year, 95% CI: -0.031, -0.007), but not in the lipid-lowering drug group ({beta} = 0.007 SD/year, 95% CI: -0.006, 0.020), with a significant interaction (P = 0.015). Similar findings were observed for the three cognitive domains. ConclusionsHigher baseline RC levels were associated with steeper cognitive decline. Regular use of lipid-lowering drugs during follow-up might attenuate the accelerated cognitive decline caused by high RC.