Eight-year parallel change in baroreflex sensitivity and memory function in a sample of healthy older adults

Abstract

Objectives To examine whether changes in the cardiac autonomic nervous system (ANS) over time, as expressed by baroreflex sensitivity (BRS), were associated with long-term changes in cognitive performance in elderly individuals without dementia. Design Community-based 8-year longitudinal study. Setting Clinical settings. Participants Individuals aged 66.9 ± 0.9 (N = 425). Measurements At baseline and follow-up, subjects underwent a clinical interview, autonomic and vascular measurements, and a neuropsychological evaluation including attentional, executive, and memory tests using standardized Z-scores. BRS was defined as being normal, moderate, or severe alteration at each evaluation. On the basis of the longitudinal changes subjects were stratified as being stable, moderate or improved. Results Mean attentional, executive, and memory change Z-scores were -0.41 ± 0.9, -0.15 ± 0.7, and -0.14 ± 0.8, respectively. BRS of 56% of the subjects remained unchanged, of 20% decreased, and of 24% improved. After regression analysis, the worsened BRS group was 1.88 times as likely to have greater memory change as the group with stable BRS (P =.02). No significant association was found between longitudinal change in BRS and attentional and executive changes. Conclusion In healthy elderly individuals, BRS decrease was associated with a weak but significant decrease in memory function. The long-term effect of BRS on memory changes may suggest a role of the ANS in cognitive decline.