Background: Dementia of the Alzheimer’s type (DAT) impacts Hispanics disproportionately, with almost a twofold elevated risk of developing DAT, as well as earlier onset of the disease, than in non-Hispanic Whites. However, the role of main risk factors for DAT, such as APOE ɛ4 and blood pressure (BP) levels, remains uncertain among Hispanics.
Objective: To investigate the association of APOE ɛ4 and BP levels, measures with 24 h ambulatory BP monitoring, with incidence of DAT in an elderly cohort of Hispanics.
Methods:1,320 participants from the Maracaibo Aging Study, free of dementia at the baseline, and with ambulatory BP measurements and APOE genotype available were included. Adjusted Cox proportional models were performed to examine 1) the incidence of DAT and 2) the relationship between BP levels and DAT according to APOE genotypes. Models were adjusted by competing risk of death before the onset of DAT. Model performance was assessed by likelihood test.
Results: The average follow-up time was 5.3 years. DAT incidence was 5.8 per 1000 person-year. APOE ɛ4 carriers had a higher risk of DAT. In unadjusted analyses, conventional, 24 h, and nighttime systolic BP levels were significantly higher in participants who developed DAT and of APOE ɛ4 carriers (p < 0.05). After adjustment for competing for risk, only higher nighttime systolic BP was associated with DAT incidence, but only among subjects carrying APOE ɛ4.
Conclusion: In this Hispanic population, both APOE ɛ4 genotype and assessment of nocturnal systolic BP (rather than diurnal or office BP) were necessary to estimate DAT risk.
Melgarejo, Jesus D.; Aguirre-Acevedo, Daniel C.; Gaona, Ciro; Chavez, Carlos A.; Calmon, Gustavo E.; Silva, Egle R.; de Erausquin, Gabriel A.; Gil, Mario; Mena, Luis J.; Terwilliger, Joseph D.; Arboleda, Humberto; Scarmeas, Nikolaos; Lee, Joseph H.; and Maestre, Gladys E., "Nighttime Blood Pressure Interacts with APOE Genotype to Increase the Risk of Incident Dementia of the Alzheimer’s Type in Hispanics" (2020). School of Medicine Publications and Presentations. 143.
Journal of Alzheimer's Disease