The impact of blood pressure variability on cognition: current limitations and new advances

Abstract

Dementia is the most common neurodegenerative disease in the aging population. Emerging evidence indicates that blood pressure (BP) variability is correlated with cognitive impairment and dementia independent of mean BP levels. The state-of-the-art review summarizes the latest evidence regarding the impact of BP variability on cognition in cognitively intact populations, patients with mild cognitive impairment, and different dementia types, focusing on the important confounding factors and new advances. This review also summarizes the potential mechanisms underlying the relationship between BP variability and cognitive impairment, and dementia, briefly discussing sex differences in the relationship. At last, current limitations and future perspectives are discussed to optimize BP management in preventing cognitive impairment and dementia.

Short-term blood pressure variability is inversely related to regional amplitude of low frequency fluctuations in older and younger adults

“…Therefore, some of the older adult participants may have had mild cognitive impairment, which could affect the study findings. However, our older adult sample was comparable to many other BPV studies using community-based samples that may or may not have included individuals with mild cognitive impairment [8] , [26] , [59] . Nevertheless, BPV may be higher in those with mild cognitive impairment when compared to older adults with normal cognition [53] , at least when BPV is measured over longer time intervals.…”

Reliability of beat-to-beat blood pressure variability in older adults

“…Sequence-based metrics, including systolic and diastolic ARV, displayed the highest test-retest reliability in the overall sample. This is likely due to their decreased susceptibility to outliers and low-frequency oscillations in beat-to-beat BP compared to dispersion and instability BPV metrics ( 57 - 59 ). This concept is illustrated in Figure 3D - E , where we can see BP dispersion metrics, such as SD, are more heavily influenced by low-frequency oscillations in BP while BP ARV is more directly influenced by beat-to-beat changes in blood pressure.…”

24-Hour Blood Pressure Variability Via Ambulatory Monitoring and Risk for Probable Dementia in the SPRINT Trial

“…24-hour and daytime BPV was related to dementia risk in the standard treatment group, whereas nighttime BPV was not associated with dementia risk in either group. There are few observational studies on ambulatory BPV and cognitive impairment/decline ( 1 , 42 ), and only one that directly compares 24-hour vs daytime vs nighttime BPV ( 25 ). Our findings with daytime BPV and not nighttime BPV are consistent with the study by McDonald et al, on relationships with cognitive decline.…”

“…Of course, it is expected that some of these mechanisms are shared across time intervals of BPV, and more research will help pinpoint specific therapeutic targets. Much of the work linking BPV to dementia risk has relied on mid- to long-term BPV ( 1 , 42 ). Recent SPRINT post hoc analyses using clinic-based BPV measured over longer time intervals reported links with dementia risk in both the standard and intensive treatment groups ( 11 , 12 ), whereas the present study using 24-hour BPV via ambulatory monitoring only found associations in the standard treatment group.…”