APOE and Lipid Level Synergy Effects on Declarative Memory Functioning in Adulthood

Abstract

This study of the general population examined interactions of the gene Apolipoprotein E (APOE) and/or lipid levels, and their effects on cognitive change. A MANCOVA model based on longitudinal data (with a 5 year follow-up) obtained from the Betula study (n = 1777; age 35–85 years) was used. The significant two-way and three-way interaction effects detected were equally frequent in tests of episodic and semantic memory. A difference in the distribution of interaction effects on episodic and semantic memory decline was also found. Men demonstrated the worst cognitive development as shown by significant two-way interaction effects on episodic memory whereas two-way interaction effects among women resulted in the worst semantic memory development. This result is discussed from the viewpoint that tests of episodic and semantic memory have different cognitive demands.This study focuses on how interaction effects of the gene APOE and vascular risk factors (such as lipid levels) affect cognitive abilities and also whether the interaction effects vary across age and sex. In this study, the main focus is on interaction effects as a phenomenon in itself.