Impairments in Information Processing Speed and Executive Function are Associated with Reduced Cardiac Autonomic Modulation in Older Adults

Background/Objectives: Cognitive decline has been increasingly linked to cardiac autonomic control, yet its relationship with specific cognitive domains, such as information processing speed and executive function, remains unclear. This study investigated the association between cardiac autonomic modulation and cognitive performance in older adults. Methods: A cross-sectional study was conducted with 101 older adults (≥60 years) from a university hospital outpatient clinic. Participants were classified as cognitively intact (WCI) or cognitively impaired but not demented (CIND) based on neuropsychological assessment. Heart rate variability (HRV) was assessed under resting conditions, focusing on time-domain parameters (SDNN, rMSSD, and pNN50). The Trail Making Test Part A (TMT-A) and Part B (TMT-B) were used to evaluate information processing speed and executive function, respectively. ANCOVA models were applied to adjust for confounders such as age, sex, and comorbidities. Results: The CIND group exhibited significantly lower HRV indices (SDNN: p<0.05, d=0.44; rMSSD: p<0.05, d=0.39; pNN50: p<0.05, d=0.40), suggesting reduced parasympathetic modulation. Participants with preserved processing speed and executive function displayed higher HRV values, with pNN50 significantly associated with processing speed (p=0.04) and SDNN with executive function (p=0.02). ANCOVA confirmed that these associations remained significant after adjusting for confounders. Conclusions: Reduced cardiac autonomic modulation, particularly parasympathetic activity, is associated with cognitive impairment in aging. Lower pNN50 was linked to slower processing speed, while lower SDNN correlated with impaired executive function, reinforcing the potential of HRV as a biomarker for neurophysiological alterations in cognition.