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 vs. controls).Methods
Participants included 54 bereaved individuals and 47 controls with a mean age of 67.12 (SD=12.11). Inflammation was measured using C-reactive protein (CRP). Self-reported sleep disturbances were measured using the Pittsburgh Sleep Quality Index (PSQI). Depressive symptoms were measured using the Center for Epidemiologic Studies Depression Scale (CES-D).Results
Sleep disturbances were not associated with elevated levels of CRP in the overall group (B=0.030, standardized β=0.122, 95% Confidence Intervals [CI]=-0.027 – 0.087, p=0.299) 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 – 0.198, p=0.032). 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 – 0.196, p=0.026) and not controls (B=-0.016, β=-0.066, 95% CI=-0.096 – 0.065, p=0.690).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 following bereavement and establish whether objective sleep has differential associations with inflammation among bereaved adults.