These changes are not only related to obesity but may be due also to sleep fragmentation induced by apnea and hypopnea, to frequent arousals leading to an increase in stress hormone levels [23], to direct effects of hypoxia on central neurotransmitters with alterations in the hypothalamus-pituitary axes and in the secretion of the peripheral endocrine glands [24], and to the effects of hypercapnia which may increase levels of adrenocorticotropic hormone (ACTH) and adrenal hormones [9, 25]. The gene discussed is POMC; the disease is obesity due to melanocortin 4 receptor deficiency.