Plasma cytokines during pregnancy provide insight into the risk of diabetes in the gestational diabetes risk group.

Aims/introduction: Gestational diabetes (GDM) is characterized by low-grade systemic inflammation, which manifests as changes in the levels of cytokines in the blood. We aimed to investigate plasma immune mediators during gestational weeks 23-28 in 213 women at risk for GDM, and to find associations between GDM and its complications.

Materials And Methods: We quantified the levels of adipokines: adiponectin, leptin, plasminogen activator inhibitor-1 and resistin; chemokines: C-C motif chemokine ligand 2 (CCL2), CCL4, C-X-C motif chemokine ligand 8 (CXCL8) and CXCL10; and cytokines: granulocyte-macrophage colony-stimulating factor, interferon-γ, interleukin (IL)-1β, soluble (s)IL-1RI, IL-2, sIL-2Ra, IL-4, IL-5, IL-6, IL-7, IL-10, IL-12(p70), IL-13, IL-15, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-27, transforming growth factor (TGF)-β1, TGF-β2, TGF-β3, tumor necrosis factor-α and soluble tumor necrosis factor receptor 2 using the Milliplex®MAP Magnetic Bead assay on Luminex®200™, and compared the results with clinical data from pregnancy and post-partum follow up.

Results: Lower levels of adiponectin and higher levels of CCL2 (Wilcoxon test, P = 3.4E-03 and P = 0.03, respectively) were found in women with GDM. IL-27 levels were associated with lower odds of GDM (adjusted logistic regression 0.90, P = 2.4E-03), and showed a risk association with glutamic acid decarboxylase autoantibody positivity (adjusted odds ratio 1.13, P = 2.8E-03). Similarly, higher IL-22 levels increased the odds of glutamic acid decarboxylase autoantibody positivity (adjusted odds ratio 4.23, P = 0.04). TGF-β1 was associated with post-partum fasting glucose levels, and CCL4 with post-partum C-peptide levels (linear regression, P = 0.04 and P = 0.01, respectively). Women who developed pregnancy complications had higher levels of CXCL10 and CCL4 (linear regression, P = 7.0E-04 and P = 0.01, respectively).

Conclusions: Plasma adiponectin and CCL2 concentrations distinguish women with GDM. IL-27 and IL-22 levels might select women with an autoimmune reaction, whereas increased TGF-β1 and CCL4 are associated with post-partum glucose and insulin metabolism.