EPO and obesity due to melanocortin 4 receptor deficiency: In relation to the level of adiposity, after age adjustment, EPO levels were found to be higher in the morbid obesity group (16.0 ± 6.1 mIU/mL) compared with the other groups of patients (10.8 ± 5.1 mIU/mL in the obesity group, 10.4 ± 4.7 mIU/mL in the overweight group, and 10.0 ± 5.3 mIU/mL in the normal-weight group; p = 0.001) (Fig. 1B).