Hepcidin in Obese Children as a Potential Mediator of the Association between Obesity and Iron Deficiency

Context: Obesity and iron deficiency are two of the most common nutritional disorders worldwide. Several studies found higher rates of iron deficiency in obese than in normal-weight children. Hepcidin represents the main inhibitor of intestinal iron absorption, and its expression is increased in adipose tissue of obese patients. Leptin is able, in vitro, to raise hepcidin expression. Objectives: Aims of this work were 1) to assess the association between poor iron status and obesity, 2) to investigate whether iron homeostasis of obese children may be modulated by serum hepcidin variations, and 3) to assess the potential correlation between leptin and serum hepcidin variations. Methods: Iron status and absorption as well as hepcidin, leptin, and IL-6 levels were studied in 60 obese children and in 50 controls. Results: Obese children showed lower iron and transferrin saturation (both P < 0.05) and higher hepcidin levels (P = 0.004) compared with controls. A direct correlation between hepcidin and obesity degree (P = 0.0015), and inverse correlations between hepcidin and iron (P = 0.04), hepcidin and transferrin saturation (P = 0.005), and hepcidin and iron absorption (P = 0.003) were observed. A correlation between leptin and hepcidin (P = 0.006) has been found. The correlation remained significant when adjusted for body mass index, sex, pubertal stage, and IL-6 values. Conclusions: We propose that in obese patients, increased hepcidin production, at least partly leptin mediated, represents the missing link between obesity and disrupted iron metabolism. (J Clin Endocrinol Metab 94: 5102-5107, 2009)