24-Hour Sleep Duration in Early Gestation is Associated with Increased Markers of Inflammation Among Women with a History of Preeclampsia

Background: Sleep duration, both short and long, is recognized as a potential contributor to adverse health conditions. This study evaluated whether long sleep duration in early gestation (15 weeks) was associated with increased circulating concentrations of inflammatory cytokines across pregnancy. Methods: Self-reported 24-hour sleep duration and blood samples were obtained concurrently at 15, 24 and 36 weeks gestation in 85 pregnant women with a history of preeclampsia. Plasma samples were assayed for the inflammatory cytokines IL-2, -6, -8, IFNγ, TNFα, GM-CSF and anti-inflammatory cytokines IL-4, -5, and -10 using Luminex technology. A ratio of pro-to-anti-inflammatory cytokines was calculated using multiples of the median (MOMs) for each relevant cytokine type to normalize the data for comparison. Data were analyzed using repeated measures mixed models. Results: Women with long sleep (≥ 9 hours) at 15 weeks gestation had higher IL-6 concentrations throughout gestation than women who were regular sleepers (p = .003). No other cytokine or the ratio of pro-to-inflammatory cytokines differed between groups. No interactions of group by time were significant. Conclusions: The tendency to sleep for more than 9 hours in early pregnancy may contribute to increased low-grade inflammation as evidenced by higher circulating concentrations of IL-6. This may initiate or augment pre-existing pathophysiology associated with adverse pregnancy outcomes. While, our data are preliminary, they direct further investigation to determine whether this association increases risk for adverse pregnancy outcomes.