Adiponectin is reduced in gestational diabetes mellitus in normal weight women

Background. Adiponectin is an adipose tissue-derived protein counteracting insulin resistance and inflammation. We have compared women with gestational diabetes mellitus (GDM; n = 22) and normal pregnancies (controls; n = 29) to evaluate whether adiponectin represents a link between endocrine function of adipose tissue and the development of diabetes during pregnancy. Methods. The participants were categorized according to their prepregnancy body mass index (BMI) into two classes: BMI < 25 and BMI = 25. Plasma concentrations of adiponectin, leptin and insulin were measured by radioimmunoassay (RIA). Total cholesterol, high density lipoprotein (HDL) cholesterol and triacylglycerol were determined by routine enzymatic methods. Expression of adiponectin/glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was determined by real-time reverse transcription polymerase chain reaction (RT-PCR) in subcutaneous adipose tissues obtained by excision at cesarean delivery. Results. Among individuals with GDM and BMI < 25 kg/m(2) (n = 8), plasma adiponectin concentration was lower than in the controls (n = 20), 8.1 +/- 1.2 mug/mL vs. 12.2 +/- 1.1 mug/mL; p = 0.04). The mean plasma leptin concentrations did not differ between the GDM and control groups. Plasma concentrations of insulin and C-peptide were significantly higher among GDM than control individuals independent of BMI. For all the women included in the study, we found that plasma adiponectin only correlated negatively with prepregnancy and third-trimester (sampling day) BMI (p = 0.03 vs. p = 0.01). In abdominal subcutaneous adipose tissue of pregnant women, adiponectin mRNA levels were lower in GDM than in control subjects (0.77 +/- 0.18 vs. 1.39 +/- 0.15; p = 0.05). Conclusions. These results indicate that low plasma adiponectin concentration is associated with GDM. In addition, we found that adiponectin mRNA levels in adipose tissue biopsies from GDM subjects were reduced.