Blood pressure variability and cognitive function in older hypertensives.

Several studies have shown that cerebrovascular organ damage can related not only to average blood pressure (BP) levels, but also to BP variability. The aim of this study was to investigate the relationship between 24 hr BP variability and cognitive function in older hypertensives. Forty older, never treated hypertensives were submitted to 24 hr ambulatory BP monitoring (ABPM) and subdivided, according to the variability of the systolic BP (SBP), in two groups: 23 with higher (> PV) and 17 with lower (< PV) SBP variability, defined as the standard deviation (SD) of the mean 24 hr SBP values and as coefficient of variation (CV). They underwent a cognitive assessment by mini mental state examination (MMSE) and a recording of the brain event-related potentials (ERPs). ERPs record neuronal electric activity when the patients are submitted to frequent and rare acoustic stimuli and must recognize and count rare (target) stimuli. The two groups with statistically different 24 hr SBP variability, did not show significant differences in MMSE scores or in N2 and P300 ERP latencies, thus indicating a lack of difference in the cognitive ability between the two groups. Our results show that cognitive function is not related to 24 hr SBP variability in older hypertensives.