Approved research

Association between blood lipid fractions and cognitive performance: a Mendelian randomisation study

Lay summary

Observational studies generated inconsistent results regarding the associations of blood lipids and lipid-lowering treatments with cognitive function. There have been no randomised controlled trials primarily investigating the effects of any lipid-lowering therapies on cognitive function. This study involving Mendelian randomisation analysis aims to explore the association of blood lipid fractions with cognitive scores and cognitive impairment in general and stroke population, respectively. In this study, we will identify British participants who provided data on lipid test results, valid genetic information and cognitive test results. Blood lipid fractions to be analysed in this study include low-density lipoprotein cholesterol(LDL-C), high-density lipoprotein cholesterol(HDL-C) and triglycerides(TG). We are primarily interested in their cognitive test scores for memory, reasoning and information processing speed. We will also investigate the association of blood lipid fractions with cognitive decline. In the Mendelian randomisation(MR) study, we can use genetic variants associated with LDL-C, HDL-C and TG, respectively, to divide participants into subgroups with different genetically determined levels of these blood lipid fractions. While multiple variants are related to each lipid fraction, we will generate allele scores and use the scores as an instrument to evaluate the causal effect of the lipid fractions on cognitive function or cognitive decline. We will compare the results from MR study with conventional observational study. We expect to spend two years in conducting this study. We will start this project when it has been approved and the data on blood lipid tests are available. This study will provide further evidence of the unintended effects of lipids and relevant modification drugs on cognitive function in general population and stroke patients. The results of this study may inform lipids management in clinical practice and future research on this topic.