Interarm differences in systolic blood pressure and the risk of dementia and subclinical brain injury

Introduction: This study examined whether interarm differences in systolic blood pressure (IDSBP) ≥10 mm Hg were associated with the risk of incident dementia and subclinical brain injury. Methods: Between 1992 and 1998, 2063 participants of the Framingham Heart Study underwent assessment of IDSBP with results related to the 10-year risk of incident dementia including clinically characterized Alzheimer's disease. Secondary outcomes included markers of subclinical brain injury on magnetic resonance imaging. Results: High IDSBP were associated with a greater risk of incident dementia (hazard ratio [HR] 1.92; 95% confidence interval [CI], 1.09-3.40) and Alzheimer's disease (HR, 2.32; 95% CI, 1.29-4.18), but only in those who carried an apolipoprotein E (APOE) ε4 allele. IDSBP also predicted lower total brain volumes and more prevalent silent brain infarcts in those who were. APOE ε4 positive. Discussion: High IDSBP were associated with an increased risk of dementia, including clinical Alzheimer's disease, and subclinical brain injury in those who were. APOE ε4 positive.