Associations of postpartum sleep, stress, and depressive symptoms with LPS-stimulated cytokine production among African American and White women

Background: Postpartum is a period of unique psychosocial stress characterized by sleep disturbance, risk for depressed mood, and heightened parenting stress. However, data on effects of these exposures on inflammatory immune function are limited. Methods: This study examined associations among sleep, psychosocial stress (i.e., parenting stress, general perceived stress), mood (i.e., depressive symptoms), serum cytokine levels, and LPS-stimulated proinflammatory cytokine production among 69 women (32 African American, 37 White) assessed at 7-10 weeks postpartum. Results: No associations between behavioral measures and serum cytokine levels were observed among women of either race. In African American women, but not Whites, poorer sleep quality, greater parenting stress, and greater depressive symptoms were associated with greater LPS-stimulated IL-6 and IL-8 production (ps <= 0.05). Also in African Americans, greater general perceived stress was associated with greater IL-8 production, and greater depressive symptoms with greater stimulated TNF-alpha production (ps <= 0.05). Simple mediation models highlighted the bidirectional relationship between stress and sleep in relation to inflammation among African American women. Conclusions: Significant effects of both stress/distress and poor sleep quality on proinflammatory cytokine production during postpartum were observed uniquely among African American women. These data are consistent with an allostatic load model which predicts that conditions of chronic stress impart vulnerability to dysregulated responses to novel stressor exposures. The bidirectional nature of the stress-sleep relationship has clinical relevance. Studies examining whether interventions focused on one or both of these psychological factors during postpartum is beneficial for inflammatory profiles would be informative. In addition, examination of these models in relation to maternal health at postpartum, including delivery related wounds and other infections, is warranted.