GPIHBP1 and obesity due to melanocortin 4 receptor deficiency: Taken together, the observed negative correlation between circulating GPIHBP1 levels and umbilical venous pO2 in GDM pregnancies suggests that circulating GPIHBP1 may serve as an indicator of placental vascular function, particularly given the multifaceted involvement of GDM and prepregnancy overweight or obesity in vascular dysfunction.