Maternal tiredness and cytokine concentrations in mid-pregnancy

Abstract

Objective: Sleep disturbances relate to altered levels of inflammatory mediators in general population, but not much is known about the associations between sleep disturbances and inflammatory mediators during pregnancy. The present exploratory study investigated whether insomnia, tiredness, general sleep quality, and insufficient sleep duration during pregnancy relate to the concentrations of maternal peripheral circulating cytokines. As sleep disturbances are frequently observed in mood disorders, the results were controlled for symptoms of depression and anxiety.

Methods: 137 participants were randomly drawn from a representative FinnBrain Birth Cohort. Serum concentrations of selected cytokines were analyzed using Multiplex bead arrays from blood samples drawn at the gestational week 24. The sleep disturbances were evaluated using the Basic Nordic Sleep Questionnaire. Depressive and anxiety symptoms were measured with the Edinburgh Postnatal Depression Scale and the anxiety subscale of the self-rated Symptom Checklist 90, respectively.

Results: Enhanced tiredness was associated with cytokine concentrations of IL-2, IL-10, IL-12, IL-13, and TNF-α. The observed associations resembled a reversed U-shaped curve rather than being linear. Having a good general sleep quality was associated with higher logarithmic cytokine concentrations of IL-2, IL-4, IL-6, IL-10, IL-12, IL-13, and IFN-γ. There was no evidence for associations between insomnia or sleep loss and cytokines.

Conclusions: Maternal subjective tiredness and good general sleep quality were associated with altered levels of immunological markers during pregnancy. The association was independent from symptoms of depression and anxiety.

Keywords: Cytokines; Immunology; Pregnancy; Sleep; Sleep quality; Tiredness.