Relationship of orthostatic blood pressure to white matter hyperintensities and subcortical volumes in late-life depression

Background Structural brain abnormalities are associated with late-life major depression, with numerous studies reporting increased white matter hyperintensities (WMH) and reduced cortical/subcortical grey matter volumes. There is strong evidence linking vascular disease to WMH, but limited evidence on its association with subcortical volumes. Aims To investigate the relationship of orthostatic blood pressure changes to WMH and subcortical grey matter volumes in late-life depression. Method Thirty-eight people with depression and a similarly aged comparison group (n=30) underwent fluid attenuated inversion recovery (FLAIR) and T-1-weighted magnetic resonance imaging as well as systematic orthostatic blood pressure assessments. Volumetric estimates of WMH and subcortical grey matter were obtained for each participant and the relationship to blood pressure drop on active stand was examined. Results An association between orthostatic systolic blood pressure drop and WMH volumes in temporal and parietal regions was found in the depression group (age-corrected partial correlation r'=0.31-0.35, P<0.05). Subcortical volumes were not related to blood pressure changes or WMH volumes in either group. Conclusions We found evidence for an association between the degree of orthostatic systolic blood pressure drop and WMH volume in the depression group. Since blood pressure drops lead to WMH in animals our findings suggest systolic blood pressure drops may be a factor contributing to these lesions in late-life depression.