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

Abstract

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.

Keywords: ABI; Alzheimer's disease; Ankle-brachial index; Atherosclerosis; Blood pressure; Cerebrovascular disease; Dementia; Framingham Heart Study; Interarm differences in systolic blood pressure; Magnetic resonance imaging; Peripheral vascular disease.

Figure 1

Selection of study participants. IDSBP = Interarm differences in systolic blood pressure; MRI = Magnetic resonance imaging. Note: MRI was performed an average of 3.8 years after IDSBP were measured. The risk of incident dementia was calculated as the 10-year risk, starting from the time of IDSBP measurement.