ABSTRACT
Objective To understand the alteration of retinol binding protein 4 (RBP4)in breast milk of women with gestational diabetes mellitus (GDM)and its clinical significance.Methods Sixty pregnant women diagnosed with GDM were selected as the cases.In the case group,breastfeeding amount reached more than 80% were defined as high -breastfeeding group while less than 20% were defined as low -breastfeeding.At the same time,45 nomal pregnant women were selected as the controls.Cord blood samples were collected during the delivery.Colostrums and mature milk samples were collected after the delivery.RBP4 and insulin concentrations were measured using enzyme -linked immunosorbent assay (ELISA ) and radioimmunoassay (RIA ) respectively.Infant birth weight and weight gain during postpartum reexamination were recorded.Results The concentrations of RBP4 and insulin in cord blood of GDM group (1 4.9 ± 2.6 μg/L and 8.3 ±1 .9 μU /mL)were higher than that in control group(1 2.4 ±2.7 μg/L and 6.0 ±2.1 μU /mL,P <0.001 ).RBP4 and insulin concentrations in colostrums of GDM group (1 6.9 ±4.2 μg/L and 1 1 .3 ±3.1 μU /mL)were higher than in controls (1 3.3 ±4.5 μg/L and 9.2 ±2.8 μU /mL,P <0.01 ).While in mature milk,RBP4 concentrations of GDMgroup were higher than that in controls (1 6.1 ±4.0 μg/L vs.1 2.5 ±3.1 μg/L,P <0.01 ).Insulin concentrationsof two groups were not significantly different.Comparing with low -breastfeeding group,RBP4 concentrations in mature milk of high -breastfeeding group were significantly lower (P <0.01 ).Cord blood RBP4 levels were positively correlated with infant birth weight (r =0.43,P <0.01 ).At the same time,in the colostrums,RBP4 levels were positively correlated with insulin levels (r =0.45,P <0.01 )and maternal weight gain during pregnancy (r =0.37,P <0.01 ).RBP4 concentrations in mature milk of high -breastfeeding group were negatively correlated with weight gain of infants (r =-0.49,P <0.01 ).Conclusion RBP4 in breast milk may be involved in the regulation of infant growth.Breastfeeding may reduce the RBP4 levels in women with GDM.