Association between circulating levels of galanin and pre-pregnancy body mass index in patients with gestational diabetes mellitus.

Galanin is an important neuropeptide which induces an increase in obesity and appetite, improving insulin sensitivity and glucose tolerance in experimental animals. Although significantly higher levels of plasma galanin are found in pregnant women with gestational diabetes mellitus (GDM), there is a limited understanding of its precise mechanism underlying this variation. In the present study, concentrations of circulating galanin were determined at baseline in pregnant women with GDM and pregnant women with normal glucose tolerance (NGT). Correlation analyses were performed between galanin and pre-gestational body weight, pre-gestational BMI, and hormone involved in various homeostatic processes. Results showed that plasma galanin level was significantly higher in the patients with GDM than in the NGT subjects (p<0.001). Plasma galanin was positively correlated with pre-gestational body weight (r=0.42, p=0.037), pre-gestational BMI (r=0.643, p=0.001), and fasting blood glucose (r=0.840, p<0.001) in the GDM group. Moreover, a significant negative correlation was shown between galanin and sex hormone binding globulin (SHBG) (r=-0.901, p<0.001) in the GDM group. These data indicate that serum galanin concentration increases markedly in pregnant women with GDM, and this increase seems to be related to the increase of pre-gestational BMI and significantly lower SHBG in patients with GDM. Thus, circulating galanin is affected under conditions of altered pre-gestational BMI with highest levels in GDM patients. The increase of galanin under conditions of GDM may indicate a physiological function to improve glucose tolerance which is often impaired in GDM subjects.