Adiposity-Related Inflammation: Effects of Pregnancy

In the nonpregnant population, there is extensive evidence of a systemic low-grade inflammatory status in relation to excess adipose tissue. Less is known about the relation during pregnancy. Objective: Our main objective was therefore to explore the effect of pregnancy on adiposity-related systemic inflammation. Design and Methods: This study is a longitudinal cohort study of 240 pregnant women of Scandinavian heritage at Oslo University hospital-Rikshospitalet, Norway from 2002 to 2005. The inflammatory markers (C-reactive protein [CRP], Interleukin-6 [IL-6], monocyte chemoattractant protein 1 [MCP-1], IL1-Ra, tumor necrosis factor receptor II, and IL-10) were measured at four timepoints during pregnancy and analyzed by enzyme immuno-assay. The women were categorized based on BMI at inclusion (BMI < 25, 25-30, and > 30 kg/m(2)). Data were analyzed by Friedman-test, Wilcoxon signed rank test, or Kruskal-Wallis test as appropriate. Results: Maternal adiposity was associated with significantly higher circulatory levels of several inflammatory markers (CRP, MCP-1, IL-6, and IL-1Ra). However, this proinflammatory upregulation was not evident toward the end of pregnancy, as levels of CRP, MCP-1, and IL-6 were not any longer significantly different between the BMI categories. Conclusions: Although normal pregnancy exhibits proinflammatory features, this does not seem to have additive or synergistic effects on the inflammation associated with adiposity. On the contrary, we found that the BMI-dependent increase in proinflammatory markers was not evident at the end of pregnancy.