Heart rate variability, blood pressure and cognitive function: Assessing age effects

Increasing age is the most significant risk factor for dementia. Aging populations see cognitive disorders becoming increasingly prevalent, unfortunately paired with high economic and social consequences. Mild cognitive impairment (MCI) is the earliest detectable stage preceding dementia. This study aimed to identify early links between heart rate variability (HRV) and blood pressure (BP) to cognitive performance. Three blood pressure readings were taken pre and post study. Electrocardiogram was recorded during both resting (baseline) and cognitive interventions (active). HRV was extrapolated using a fast Fourier transform algorithm to produce low and high frequency bandwidths. Two psychometric tools were administered to assess cognitive domains such as memory, reasoning and visual construction ability. In the youngest age group, 18-35 years, higher blood pressure was detrimental to judgment and orientation but beneficial to calculation and memory skills. Higher sympathetic drive (low frequency) impaired language, recall and attention ability. In the middle age group (36-50 years) higher blood pressure predicted decline in comprehension, orientation and attention domains. Higher sympathetic activity (low frequency) was linked to decreases in various domains such as similarity and construction. The oldest group (51-65 years) showed higher blood pressure precipitated declines in recall ability and high sympathetic activity (low frequency) impaired orientation func-tion. These various associations suggest autonomic activity biomarkers for cognitive impairment vary according to age. Few studies confirm specific autonomic implications on cognition from young to older age. The cognitive associations reported highlight the potential importance of autonomic activity as a predictive tool for cognitive decline. Early detection of cognitive impairment allows for intervention methods to be applied sooner to slow or cease cognitive decline progression. © 2013 River Publishers