The individual and dyadic roles of neuroticism and conscientiousness in cardiac autonomic functioning of patients with cancer and their spousal caregivers.

Poor cardiovascular health is prevalent among patients with cancer and their spousal caregivers, partly due to cancer-related stress. This study examined the roles of neuroticism and conscientiousness, two stress regulatory tendencies, in heart rate variability (HRV; RMSSD) among patient-caregiver dyads. Patients newly diagnosed with colorectal cancer (N = 141, 56.33 years old, 34 % female, 64.54 Hispanic) and their spousal caregivers (N = 139, 55.46 years old, 62.77 % female, 62.77 % Hispanic) completed personality measures individually and underwent a laboratory stress task together, while cardiac functioning was continuously recorded. When adjusting for respiration rate, patients' higher neuroticism was associated with their own higher RMSSD at rest, and caregivers' higher conscientiousness was associated with their own poorer RMSSD recovery from stress. Dyadically, caregivers' higher neuroticism was linked with patients' slower RMSSD recovery. When respiration rate was not adjusted, the association involving patients' neuroticism became non-significant while several associations involving caregivers' conscientiousness became significant. Supplemental models involving respiration rate and heart rate found that one's higher conscientiousness was linked to one's own lower respiration rate at rest, greater respiratory and heart rate reactivity, and slower respiratory recovery. Additionally, one's neuroticism was associated with partner's blunted heart rate reactivity. Overall, patients' and caregivers' neuroticism served differential roles in patients' cardiac health, whereas caregivers' conscientiousness was deleterious for their own cardiac stress recovery. These results highlighted the unique roles within and between self-regulation tendencies in dyads newly affected by cancer.