Comparison of leukocyte IL6 expression in patients with gestational diabetes mellitus (GDM) diagnosed by the Polish Diabetes Association (PDA) 2011 and 2014 criteria.

Abstract

Controversial data exist in the literature regarding relationship of IL-6 with gestational diabetes mellitus (GDM), partially resulting from different criteria for GDM classification. In the present study, we revised this linkage by investigating leukocyte IL6 expression and its associations with clinical characteristics of patients diagnosed by the Polish Diabetes Association (PDA) 2011 and 2014 criteria. A total of 145 pregnant women underwent 75 g two-hour OGTT, and GDM was diagnosed according to PDA 2011 criteria (GDM/PDA 2011 group; n = 113) and PDA 2014 criteria (GDM/PDA 2014 group; n = 104). IL6 gene expression was investigated in leukocytes of all participants by using real-time PCR method. Compared to respective NGT control groups, the GDM/PDA 2011 group exhibited higher FPG, two-hour OGTT, HbA1C and IL6 expression and lower HDL-C, whereas the GDM/PDA 2014 group had higher FPG, one-hour and two-hour OGTT, HbA1C and HOMA-IR, lower QUICKI-IS, and unchanged IL6 expression. No differences in metabolic parameters and IL6 expression were found between the two GDM groups. Compared to the NGT/PDA 2011 group, the NGT/PDA 2014 group had lower one-hour and higher two-hour OGTT and increased IL6 expression. With PDA 2014 criteria, IL6 expression correlated positively with two-hour OGTT in both NGT and GDM groups as well as with LDL-C in NGT group, and negatively with HDL-C in NGT group. With PDA 2011 criteria, no associations were evident in NGT and GDM groups. Nevertheless, significant positive correlation of IL6 mRNA with two-hour OGTT was observed in the entire study group. Differences in metabolic phenotypes as well as gene expression and correlation data between GDM and NGT groups, categorised based on PDA 2011 and 2014 criteria, are related to changes in gestational glucose tolerance status resulting from using PDA 2014 criteria. Moreover, our findings support the hypothesis that IL-6 is associated with glucose metabolism during pregnancy.