Blood pressure variability and mind cognition impairment: a systemic review and meta-analysis

Blood pressure variability is hypothesized to play important role in development of cognition impairment. We aimed to explore the relationship of blood pressure variability and cognition impairment.We searched the following databases, EMBASE, Cochrane Library, Web of Science, up to October 2021 using blood pressure variability, cognition impairment, cognition dysfunction. Randomized double blind and observational trials were included. Dementia and Alzheimer's disease cases were excluded. Two reviewers confirmed the inclusion of studies and extracted the data independently. STATA V.15.1 was used to synthesize data.We included 23 studies and enrolled 42964 hypertensive patients. All studies assessed cognition function using Mini-Mental State Examination (MMSE) or other cognition function test. Ambulatory blood pressure variability, visit-to-visit blood pressure variability, measure to measure blood pressure variability, day-to-day blood pressure variability and beat-to-beat systolic blood pressure variability were applied in included trials. The variability of systolic blood pressure has significant relationship with cognition impairment (OR,1.747[1.25,2.44], P < 0.01), however, the variability of diastolic blood pressure did not show relationship with decreasing cognition function scale(OR,0.912[0.81,1.03], P> 0.05) by nalysing data which trial used MMSE scale. Results showed higher systolic blood pressure variability had negative relationship with attention (OR,1.63, [1.28,1.98], P < 0.01). In the aspect of memory and language function, blood pressure variability did not show a significant relationship. Higher blood pressure variability in both systolic and diastolic was associated with lower hippocampal volume and cortical infarcts.The variability of systolic blood pressure is dependently risk factor for cognition impairment in older adults with hypertension. For unsuccessfully treated hypertensive individuals (with blood pressured more than 140/90 mmHg),higher variability in both systolic and diastolic blood pressure was associated with cognitive damage, but these associations were not found in those controlled hypertension older adults.