Since the influence of age on the level of the studied parameters which related to iron metabolism cannot be excluded, further research concerning the relations between the ferroportin/hepcidin axis in obesity are needed and should be conducted on a larger group of subjects, assessing the potential impact of age on the hepcidin as well as the ferroportin levels. Here, SLC40A1 is linked to obesity due to melanocortin 4 receptor deficiency.