Although prior work has examined the relation of heart rate variability (HRV) to cognitive impairment, findings have been inconsistent. The association of cardiac vagal control with cognitive impairment remains unclear. Our goal was to examine the association of high frequency HRV (hf-HRV) with mild cognitive impairment and global cognition in a community-based sample of older adults. 84 participants (mean age 78.1 SD 5.2 years) wore single lead ECG devices for 6-9 days. HRV in the high (0.15-0.40 Hz, HF-HRV) frequency band was derived using power spectral analyses. The cognitive battery included the Montreal Cognitive Assessment (MoCA) to assess global cognition, and two tests per domain for memory, executive, language, visuo-spatial and attention. Mild Cognitive Impairment (MCI) was defined using Jak-Bondi criteria. Domain specific impairment was defined as scores > 1.0 SD below age, sex, education standardized norms on at least one test in a domain. Associations of HF-HRV with cognition were examined using logistic and linear regression adjusted for demographics, diabetes, and hypertension. Participants were 82% female; 39% Non-Hispanic White, 44% Non-Hispanic Black, 25% had MCI. Within domains, impairment was present in 25% (memory), 28.6% (executive function), 21.4% (attention), 17.9% (language), and 27.4% (visuospatial). HF-HRV was inversely associated with prevalent MCI (OR per 1 SD increase in ln HF-HRV: 0.47, p = 0.02) and with memory impairment (OR per 1 SD increase in ln HF-HRV: 0.52, p = 0.03). Higher HF-HRV was associated with higher MoCA score (β for 1 SD increase in ln HF-HRV = 0.65, p = 0.046). Higher hf-HRV, indicative of greater cardiac parasympathetic control is associated with lower odds of MCI, or memory impairment and with better global cognition after adjustment for cardiovascular risk factors. Future longitudinal studies are needed to confirm these associations.
Derby et al. (Fri,) studied this question.