Endocrine Abstracts

Background: Osteocalcin (Ost) is an osteoblast derived protein locally acting on bone formation. Ost could also have a role in regulation of glucose and fat metabolism. It has been shown that Ost can directly stimulate proliferation of β cells and have effect on secreting insulin, and can act on insulin sensitivity by cytokines. It was not fully investigated in gestational diabetes mellitus. The aim of our study was to investigate osteocalcin in Turkish gestational diabetes mellitus and its subgroups.

Methods: We performed a case–control cross sectional study and evaluated all the demographic and anthropometric parameters of 80, age and body mass indices similar pregnant women, half of them having normal glucose metabolism (NGT) and the other half having gestational diabetes mellitus (GDM). We classified the women according to age, parity, body mass index, and vitamin D levels and compared Ost levels, calcium metabolism, glucose, lipid and insulin resistance parameters and correlation of all the parameters in NGT, GDM and in GDM subgroups.

Results: Osteocalcin levels were high, but not-significant, in gestational diabetes group and also in old, multiparous, having low Vitamin D and high BMI gestational diabetes subgroups. There was a positive correlation between Osteocalcin and C peptide in GDM and GDM subgroups having age>30, multiparous, Vitamin D>20 ng/ml, BMI>30 kg/m² (r=0.424, P<0.01; r=0.466, P<0.05; r=0.408, P<0.05; r=0.520, P<0.05; r=0.603, P<0.01; respectively) and a negative correlation between Osteocalcin and HDL-Cholesterol in GDM subgroups having multiparous, Vitamin D>20 ng/ml and BMI <30 kg/m² (r=−0.334, P<0.05; r=−0.352, P<0.05; r=−0.430, P<0.05; r=−0.442, P<0.05; respectively).

Conclusion: We concluded that Ost may play a role in Turkish GDM and it increases in order to cope with beta cell dysfunction and insulin resistance which are important in GDM etiopathogenesis. Although we could not demonstrate statistically significant high levels of Ost in our GDM patients and in all subgroups, probably due to our relatively small group and subgroup sizes we think that multiparity, high BMI, low Vitamin D levels provide negative conditions for especially insulin resistance was concerned.