Education and income might protect the brain differently against white matter lesions in aging

Abstract

AbstractBackgroundA lower socioeconomic status (SES) is associated with poorer cognitive health in old age and with more white matter lesions in the brain. It is not clear whether education and income, the two major components of SES, contribute differently to cognitive health, given that education is believed to build up a cognitive reserve. Aim of the study was to investigate how education and income independently contribute to cognitive functioning and brain white matter in aging.MethodParticipants (age 40‐80 years) of the representative population‐based LIFE‐Adult study completed the CERAD neurological test battery and underwent MR scanning (n=2,385 without neurological diseases). The association between education and income on cognitive performance and white matter lesions was analyzed via generalized linear regression modelling adjusted for age, gender, APOE e4 allele and household size. We further tested whether health (heart disease, high blood pressure, elevated blood lipids, diabetes, depression) could explain the associations.ResultHigher education as well as higher income were significantly associated with better performance in the CERAD and fewer total white matter hypointensities (WMH). Only higher education was associated with a lower Fazekas scale score, while only higher income was associated with fewer periventricular WMH. With increasing age, the protective effect of both, higher education and higher income, on performance in the Trail Making Test B and the total white matter volume increased. Older age additionally increased the protective effect of higher income on fewer total and periventricular WMH. The age‐related association between income and periventricular WMH was largely explained by high blood pressure.ConclusionOur findings suggest that higher education and higher income may protect cognitive functioning by a smaller loss of white matter in aging. While education is associated with WMH in general, income is specifically associated with periventricular WMH, an ageing‐related association that seems to be related to blood pressure. As none of the other health indicators explained our findings, more research is necessary to investigate what aspects of low educational attainment and low income bring about WMH.