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Background: Emerging evidence has linked electrocardiographic parameters with serum adhesion molecules and cognition; however, their interrelationship has not been explored. Objective: We sought to investigate the associations of ventricular depolarization and repolarization intervals with serum adhesion molecules and cognitive function among rural-dwelling older adults. Methods: This population-based study engaged 4,886 dementia-free participants (age ≥60 years, 56.2% women) in the baseline examination (March-September 2018) of MIND-China. Of these, serum intercellular and vascular adhesion molecules (ICAM-1 and VCAM-1) were measured in 1591 persons. We used a neuropsychological test battery to assess cognitive function. Resting heart rate, QT, JT intervals, and QRS duration were assessed with electrocardiogram. Data were analyzed using general linear models adjusting for multiple confounders. Results: Longer JT interval was significantly associated with lower z-scores of global cognition (multivariable-adjusted β= –0.035; 95% confidence interval = –0.055, –0.015), verbal fluency (–0.035; –0.063, –0.007), attention (–0.037; –0.065, –0.010), and executive function (–0.044; –0.072, –0.015), but not with memory function (–0.023; –0.054, 0.009). There were similar association patterns of QT interval with cognitive functions. In the serum biomarker subsample, longer JT and QT intervals remained significantly associated with poorer executive function and higher serum adhesion molecules. We detected statistical interactions of JT interval with adhesion molecules (pinteraction <0.05), such that longer JT interval was significantly associated with a lower executive function z-score only among individuals with higher serum ICAM-1 and VCAM-1. Conclusion: Longer ventricular depolarization and repolarization intervals are associated with worse cognitive function in older adults and vascular endothelial dysfunction may play a part in the associations.

Background: Evidence has emerged that altered ventricular electrocardiogram profiles are associated with dementia, but the neuropathological mechanisms underlying their associations are poorly understood. Objective: To investigate the interrelationships of ventricular electrocardiogram profiles with dementia and plasma Alzheimer’s disease (AD) biomarkers among older adults. Methods: This population-based cross-sectional study included 5,153 participants (age ≥65 years; 57.3% women) living in rural communities in China; of these, 1,281 had data on plasma amyloid-β (Aβ)40, Aβ 42, total-tau, and neurofilament light chain (NfL) protein. The QT, QTc, JT, JTc, QRS intervals, and QRS axis were derived from the 10-second electrocardiogram recording. The DSM-IV criteria were followed for clinical diagnosis of dementia, the NIA-AA criteria for AD, and the NINDS-AIREN criteria for vascular dementia (VaD). Data were analyzed using general linear models, multinomial logistic models, and restricted cubic splines. Results: Of the 5,153 participants, 299 (5.8%) were diagnosed with dementia, including 194 with AD and 94 with VaD. Prolonged QT, QTc, JT, and JTc intervals were significantly associated with all-cause dementia, AD, and VaD (p < 0.05). Left QRS axis deviation was significantly associated with all-cause dementia and VaD (p < 0.01). In the subsample of plasma biomarkers (n = 1,281), prolonged QT, JT, and JTc intervals were significantly associated with a lower Aβ 42/Aβ 40 ratio and higher plasma NfL concentrations (p < 0.05). Conclusion: Alterations in ventricular repolarization and depolarization are independently associated with all-cause dementia, AD, VaD, and AD plasma biomarkers in older adults (age ≥65 years). Ventricular electrocardiogram parameters may be valuable clinical markers for dementia and the underlying AD pathologies and neurodegeneration.