RESUMO
OBJECTIVE: To evaluate the associations of glycemic control and gestational age with ghrelin and proinsulin levels in cord blood and mothers' peripheral blood during pregnancy. METHODS: This is a cross-sectional comparative study of twenty-four pregnant women with gestational diabetes (GD), 18 with type 2 diabetes mellitus (T2DM), and 36 without diabetes, as well as their neonates. Levels of proinsulin, ghrelin, and glycated hemoglobin A1c (HbA1c) were measured from maternal blood during the last week before caesarian delivery and in neonatal umbilical cord blood samples. RESULTS: Mothers with GD and T2DM had significantly lower ghrelin levels compared to the healthy mothers (p<0.001). Maternal proinsulin was lower in women with GD than in women without diabetes (p<0.001). Proinsulin was significantly elevated in the neonates of women with GD and in women with HbA1c ≥6.5% (p<0.001). However, maternal ghrelin levels were higher (p=0.031) and neonate proinsulin levels lower in the pre-term offspring of mothers with GD (p=0.033). There was a negative correlation between HbA1c levels and birth weight (r=-0.407, p<0.001). CONCLUSION: Ghrelin levels were lower in pregnant women with diabetes, although pre-term birth appeared to reverse this trend in GD. Proinsulin levels were also low in pregnant women with diabetes and even lower in pre-term vs. at-term births. Both ghrelin and proinsulin levels were lower in pregnant women with diabetes and HbA1c of <6.5%. Thus, ghrelin participates in the adaptation to the caloric imbalance of diabetic pregnancy and may play a similar role in pregnancy-related complications, since high ghrelin concentrations may be necessary for normal fetal development.
