Depressive symptoms and proinflammatory cytokines across the perinatal period in African American women

Background: Comparatively few studies have examined the biological mechanisms that may underlie the reported racial disparities in antenatal and postpartum depression. Objective: To examine the associations among race, depressive symptoms and the proinflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α across the perinatal period in a diverse sample of healthy pregnant women at elevated psychosocial risk. Methods: 171 subjects were enrolled. Women were interviewed and blood samples drawn at 18 and 32 weeks gestation and 6 weeks and 6 months postpartum. Depressive symptoms were measured using the Edinburgh Postnatal Depression Scale. Serum levels of IL-6 and TNF-α were assayed using high sensitivity enzyme-linked immunosorbent assay kits. Results: Compared with non-African American (AA) women, AA women had significantly higher levels of IL-6 (est. diff=0.521, p=0.02, confidence interval (CI): 0.088-0.954) but not TNF-α across all time points (est. diff=-0.060, p=0.80, CI: -0.517 to 0.397). IL-6 was not associated with depressive symptoms but differences in IL-6 were accounted for by greater Body Mass Index in AA women. Conclusions: Compared with non-AA women, AA women entered pregnancy with elevated inflammatory cytokine levels that persisted across the perinatal period. This group difference in inflammation did not suggest increased risk for depression, but suggests other implications for long-term health.