Different association patterns of emotion regulation and heart rate variability in older and younger adults

Several mental health conditions seen in older people are associated with impaired emotion regulation. Heart rate variability (HRV) may be an index of emotion regulation capacity, but it is unclear whether and how aging influences this association. Early neurodegenerative processes, such as Alzheimer's disease-related reduction of locus coeruleus (LC) integrity, may play a role, as LC modulates both HRV and self-regulatory networks. We pre-registered a cross-sectional study to investigate the relationship between measures of emotion regulation, HRV and LC structural MRI integrity in a lifespan sample of cognitively normal healthy adults (n = 678, aged 18-88 years, 51% female), recruited between 2010 and 2012 as part of the Cambridge Centre for Ageing and Neuroscience (Cam-CAN) cohort. We hypothesized that age-related differences in the HRV-emotion regulation relationship could be attributed to reduced LC integrity in older versus younger adults. Exploratory analyses incorporated alternative and novel measures of emotionality and LC rostro-caudal functional connectivity gradients from more recent Cam-CAN studies. In contrast to younger adults, we found an inverse relationship between resting HRV and measures of emotion regulation performance in older adults. There was no evidence that LC integrity influenced this relationship. A more 'old-like' LC rostro-caudal functional connectivity gradient, but not LC signal intensity, was related to lower HRV and worse reappraisal outcomes. We identify complexity in the association between HRV and emotion regulation with age and gaps in understanding of the relationship between different measures of LC integrity. Future studies should explore compensatory mechanisms underlying age-related differences in autonomic and emotion regulation.