Carotid Plaque in Alzheimer Caregivers and the Role of Sympathoadrenal Arousal

Objectives: To test the hypothesis that those who provide care for a spouse diagnosed with Alzheimer's disease would have increased prevalence of carotid artery plaque compared with noncaregiving controls and that prolonged sympathoadrenal arousal to acute stress would relate to this difference. Providing care for a spouse with Alzheimer's disease has been associated with an increased risk of coronary heart disease, potentially due to the impact of caregiving stress on the atherosclerotic disease process. Methods: Participants were 111 spousal caregivers (74 +/- 8 years of age; 69% women) to patients with Alzheimer's disease and 51 noncaregiving controls (75 +/- 6 years of age; 69% women). Inhome assessment of carotid artery plaque via B-mode ultrasonography was conducted. Plasma catecholamine response to an acute speech stressor task was also measured. Results: Logistic regression indicated that caregiving status (i.e., caregiver versus noncaregiver) was associated significantly with a 2.2 times greater odds for the presence of plaque independent of other risk factors of atherosclerosis (95% confidence interval, 1.01-4.73, p=.048). Decreased recovery to basal levels of epinephrine after a psychological stress task was associated significantly with the presence of plaque in caregivers, but not in noncaregivers. Norepinephrine recovery post stressor was not associated with plaque in either group. Conclusions: Caregivers had a higher frequency of carotid plaque compared with noncaregivers. Poorer epinephrine recovery after acute stress was associated with the presence of plaque in caregivers but not in noncaregivers. A prolonged sympathoadrenal response to acute stress might enhance the development of atherosclerosis in chronically stressed Alzheimer caregivers.