A later study by Marousez and coworkers [150] analyzed the maternal plasma and breast milk apelin levels in relation to maternal GDM and obesity and demonstrated that the plasma apelin levels were significantly affected; namely lower levels were observed for obese mothers with GDM (~0.15 ng/mL) and without GDM (~0.19 ng/mL) than for non-obese mothers (~0.24 ng/mL). This evidence concerns the gene APLN and obesity due to melanocortin 4 receptor deficiency.