Joint effect of mid and late life blood pressure on the brain
Objective: We hypothesized that in participants with a history of hypertension, lower late life blood pressure (BP) will be associated with more brain pathology. Methods: Participants are 4,057 older men and women without dementia with midlife (mean age 50 6 years) and late life (mean age 76 5 years) vascular screening, cognitive function, and brain structures on MRI ascertained as part of the Age, Gene/Environment Susceptibility (AGES) Reykjavik Study. Results: The association of late life BP to brain measures depended on midlife hypertension history. Higher late life systolic and diastolic BP (DBP) was associated with an increased risk of white matter lesions and cerebral microbleeds, and this was most pronounced in participants without a history of midlife hypertension. In contrast, in participants with a history of midlife hypertension, lower late life DBP was associated with smaller total brain and gray matter volumes. This finding was reflected back in cognitive performance; in participants with midlife hypertension, lower DBP was associated with lower memory scores. Conclusion: In this large population based cohort, late life BP differentially affects brain pathology and cognitive performance, depending on the history of midlife hypertension. Our study suggests history of hypertension is critical to understand how late life BP affects brain structure and function.
Neurology