Introduction: Obesity is the direct cause of a number of immediate problems during childhood. Recently, fat mass was described as a significant negative predictor of serum iron. Hepcidin is a hormone stimulated by an increase in plasma iron levels and iron deposits in tissues, and decreases iron release from macrophages and duodenal enterocytes into the plasma. This protein prevents excessive iron absorption and iron accumulation in tissues. Ferritin is the most commonly deployed indicator for determining iron deficiency. Several studied showed an association between obesity and iron deficiency in children, but the pathophysiological mechanisms linking these nutritional disorders are not well understood. The aim of this study was to investigate serum hepcidin, ferritin and iron concentrations in obese and non-obese children during prepubertal period.
Methods: We determined serum concentrations of hepcidin, ferritin, and iron in 30 obese children (z-score BMI≥2SD) aged 510 years. Exclusion criteria were: (a) presence of endocrine disorders or genetic syndromes, including syndromic obesity; (b) other chronic medical conditions; (c) intake of medications that could affect growth, pubertal development, nutritional or dietary status; (d) patients who did not sign the informed consent. The control group consisted of 30 non-obese children (z-score BMI <−1+1>). We assessed the average daily energy intake and the percentage of energy intake from protein, fat and carbohydrates in the diets of obese and non-obese children. Average daily food rations and their nutritional value were calculated using nutritional analysis software (Dieta 5®).
Results: Serum hepcidin concentration was higher by about 40% in obese than non-obese children (P<0.05). Similar values of ferritin and iron in both studied groups were found. Ferritin/hepcidin (P<0.05) ratio was almost 2-fold lower in obese children than controls. In obese children, hepcidin concentrations correlated negatively with BMI values (P<0.05), and positively with ferritin concentrations (P<0.01). Daily energy intake in children with obesity were higher (P<0.001) compared with the controls, but proportions of proteins, carbohydrates and fats in daily energy intake were similar in both groups. The diet of obese children had higher intake of iron (P<0.01) and vitamin C (P<0.001) than the diet of normal-weight children.
Conclusions: Our preliminary study suggests that higher hepcidin concentrations may not affect the serum level of iron in prepubertal obese children with sufficient iron consumption.
27 - 29 Sep 2018
European Society for Paediatric Endocrinology