Autonomic Function and Cognitive Function in the U.S. POINTER Neurovascular Ancillary Study.

Background: Autonomic regulation plays a major role in maintaining stable blood supply to the brain. Impaired autonomic function, as evidenced by high blood pressure variability (BPV) and/or low heart rate variability (HRV), is common in older adults and is associated with reduced perfusion, which can ultimately lead to impaired cognitive function. The U.S. POINTER Neurovascular (POINTER‐NV) ancillary study is an ongoing study designed to evaluate autonomic function in participants from the U.S. POINTER trial. Here we describe the baseline characteristics of the POINTER‐NV participants, focusing on autonomic measures and their relationship to cognitive function. Method: Continuous blood pressure and ECG recordings were used to assess BPV, HRV, and sympathovagal balance. Autonomic variables were compared according to cognitive status using the baseline Clinical Dementia Rating Scale Sum of Boxes (CDR‐SB) score. Linear regression was used to assess cross‐sectional associations between sympathovagal balance and BPV variables and composite scores for global cognition, executive function, memory, and processing speed, with and without adjustment for age, sex, and race/ethnicity. Result: Autonomic measures were available for 212 POINTER‐NV participants (mean age: 67.9 ± 5.4 years, 67% female, 33% people of color). There were no significant differences in BPV or HRV measures between participants with normal cognition (CDR‐SB score = 0) and those with possible cognitive impairment (CDR‐SB score = 0.5–1.0). Higher sympathovagal balance was significantly associated with higher scores of global cognition, executive function, and processing speed; however, this association became statistically insignificant after adjustment for age, sex, and race/ethnicity. Higher BPV measured as standard deviation of mean arterial pressure (SDMAP) was associated with lower scores for episodic memory after adjustment for age, sex, and race/ethnicity (p = 0.03). There was some suggestion that lower HRV might be associated with worse cognition, however, these associations were inconsistent across cognitive domains and did not remain after covariate adjustment. Conclusion: Age‐related changes in autonomic function can promote cognitive decline and dementia. Our data are consistent with prior evidence suggesting a role for sympathovagal balance and blood pressure variability in modulating cognitive function [ABSTRACT FROM AUTHOR]