Heart Rate Variability is Associated with Global Cognition and Cognitive Impairment: Results from the Einstein Aging Study

AbstractBackgroundThe role of autonomic function in cognitive impairment is unclear. Heart rate variability (HRV) provides a feasible, non‐invasive measure of cardiac autonomic control. We examined whether HRV is associated with global cognition and cognitive impairment using 7‐day ambulatory ECG assessments in the Einstein Aging Study.MethodAnalyses included 84 participants free of dementia (mean age 78.1 (± 5.2) years; 82% female; 39% non‐Hispanic White, 44% non‐Hispanic Black, mean education 14.7 (± 3.3 years)). Participants wore a small, single lead ECG device continuously over 7 days. Power spectral analyses were applied to determine HRV over 5‐minute epochs in the high (0.15‐0.40 Hz, hfHRV) and low (0.04‐0.15 Hz, lfHRV) frequency bands, and values were log transformed. Demographics, comorbidities, and cognition were assessed during clinic visits. Two tests per domain evaluated memory, executive function, language, visuo‐spatial and attention with impairment defined as performance ≥ 1.5 SD below the age, sex, education standardized norm on at least one test. Global cognition was assessed using the MoCA, and Mild Cognitive Impairment (MCI) was defined using Jak‐Bondi criteria. Associations of HRV with cognition were examined using logistic (MCI, domain specific impairment) and linear (MoCA) regression adjusting for age, sex, race/ethnicity and education, diabetes, and hypertension.ResultMean MoCA score was 24 (SD 3.5), 21 (25%) had MCI and impairment was identified in 25% (memory), 28.6% (executive function), 21.4% (attention), 17.9% (language) and 27.4% (visuospatial). Both hfHRV and lfHRV were inversely associated with MCI (OR per 1 SD increase in log HRV: 0.47, p = 0.02 for hfHRV and 0.42, p = 0.01 for lfHRV) and with memory impairment (OR per 1 SD increase in log HRV: 0.52, p = 0.03 for hfHRV and 0.43, p = 0.01 for lfHRV). Higher hfHRV and lfHRV were each associated with better MoCA score (β for 1 SD increase in log HRV: 0.65, p = 0.046 for hfHRV; 0.80, p = 0.02).ConclusionWhether HRV is associated with cognitive impairment remains unclear, particularly the role of hfHRV, indicative of parasympathetic control. Findings suggest that hfHRV is related to cognitive performance and impairment. Results for lfHRV also suggest joint effects of the sympathetic and parasympathetic systems.