Key points are not available for this paper at this time.
OBJECTIVE: The relationship between long-term blood pressure exposure and DTI-ALPS of the brain, a noninvasive technique that utilizes diffusion tensor imaging to quantify the diffusivity of water molecules within the perivascular space, in the general population remains unknown. This study aimed to investigate the associations between cumulative exposure of blood pressure and neuroimaging metrics associated with glymphatic function, which plays a crucial role in maintaining cerebral homeostasis by facilitating fluid exchange and eliminating metabolic waste. METHODS: A multicenter, community-based cohort study involving 955 participants was conducted. Analysis of diffusion tensor image analysis along the perivascular space (DTI-ALPS), which can reflect the glymphatic function, was conducted using brain MRI data collected from 2020 to 2022. Cumulative systolic and diastolic blood pressure (cSBP, cDBP) during follow-up periods of 4, 8, and 12 years prior to neuroimaging data acquisition were calculated. Generalized linear models were employed to assess the association between cSBP and cDBP exposure across different time periods and the DTI-ALPS index. RESULTS: The mean age of participants was 55 years, with females accounting for 45.9 %. Participants with higher cDBP over 90 mmHg during a follow-up period of 12 years exhibited a lower average DTI-ALPS index compared to normotensive individuals (beta = -0.038, 95 % confidence interval CI -0.068 to -0.008). This association remained significant among middle-aged individuals aged 45 to 60 years (beta = -0.050, 95 % CI -0.097 to -0.003). No statistical difference was observed regarding high cSBP exposure or for groups with shorter follow-up periods. CONCLUSION: Prolonged exposure to high cDBP is associated with low DTI-ALPS, potentially indicating impaired glymphatic function. This implies that managing DBP may have a greater impact on brain health than systolic blood pressure, particularly during midlife. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT05453877.
Guo et al. (Wed,) studied this question.