A 5-year longitudinal study of the relationships between stress, coping, and immune cell β2-adrenergic receptor sensitivity

Caring for a spouse with Alzheimer's disease (AD) is associated with overall health decline and impaired cardiovascular functioning. This morbidity may be related to the effects of caregiving stress and impaired coping on β2-adrenergic receptors, which mediate hemodynamic and vascular responses and are important for peripheral blood mononuclear cell (PBMC) trafficking and cytokine production. This study investigated the longitudinal relationship between stress, personal mastery, and β2-adrenergic receptor sensitivity assessed in vitro on PBMC. Over a 5-year study, 115 spousal AD caregivers completed annual assessments of caregiving stress, mastery, and PBMC β2-adrenergic receptor sensitivity, as assessed by in vitro isoproterenol stimulation. Heightened caregiving stress was associated with significantly decreased receptor sensitivity, whereas greater sense of personal mastery was associated with significanty increased receptor sensitivity. These results suggest that increased stress may be associated with a desensitization of β2-receptors, which may contribute to the development of illness among caregivers. However, increased mastery is associated with increased receptor sensitivity, and may therefore serve as a resource factor for improved health in this population.