Parental lifespan and polygenic risk score of longevity are associated with white matter hyperintensities

Abstract

Human longevity is moderately heritable and is hence influenced by both genetic and environmental factors. However, there remains considerable uncertainty regarding its relationship with brain ageing. In this study, we investigated the associations of parental lifespan (parental age at death) and polygenic risk score for longevity (longevity-PRS) with structural magnetic resource imaging (MRI) brain metrics considered to reflect the brain ageing process. We used a discovery sample (N = 19136) from the UK Biobank and a replication sample (N =809) from the Sydney Memory and Ageing Study and the Older Australian Twins Study. We found lower cerebral white matter hyperintensity (WMH) volumes to be significantly associated with longer parental lifespan in the discovery and replication samples and higher longevity-PRS in the discovery sample and a similar trend in the replication sample. The association of longevity-PRS with WMH remained significant after removing the influence of the apolipoprotein E locus. Additionally, the effects of longevity-PRS on the association were more prominent in males, especially in the older-male group. Our findings suggest that human longevity-related genes may have an influence on WMH burden, suggesting WMH volume may be a biomarker for longevity and an ageing endophenotype.