Objective: Spousal bereavement is linked to increased mortality and morbidity from inflammatory conditions. It also has a significant impact on sleep disturbances. Evidence from experimental studies indicates that chronic stress may prime individuals to have an exaggerated inflammatory response to acute stress. In this study, we examined the association between self-reported sleep disturbances and inflammation after adjusting for depressive symptoms and determined whether this association varies by bereavement status (bereaved individuals versus controls).
Methods: Participants included 54 bereaved individuals and 47 controls with a M (SD) age of 67.12 (12.11) years. Inflammation was measured using C-reactive protein. Self-reported sleep disturbances were measured using the Pittsburgh Sleep Quality Index. Depressive symptoms were measured using the Center for Epidemiologic Studies Depression Scale.
Results: Sleep disturbances were not associated with elevated levels of C-reactive protein in the overall group (B = 0.030, standardized β = 0.122, 95% confidence interval [CI] = -0.027 to 0.087, p = .299) after adjusting for depressive symptoms. Results indicated, however, that bereavement moderated the association between inflammation and sleep disturbances (B = 0.104, β = 0.517, 95% CI = 0.009 to 0.198, p = .032). Stratified analyses demonstrated that these associations differed across groups. Associations were significant among bereaved individuals (B = 0.104, β = 0.406, 95% CI = 0.013 to 0.196, p = .026) and not controls (B = -0.016, β = -0.066, 95% CI = -0.096 to 0.065, p = .690).
Conclusions: These findings provide preliminary evidence that bereavement moderates the association between self-reported sleep disturbances and inflammation. Future studies should examine the course of sleep disturbances after bereavement and establish whether objective sleep has differential associations with inflammation among bereaved adults.