Zinc nutritional status and its relationships with hyperinsulinemia in obese children and adolescents.

A perturbation of zinc metabolism has been noted in subjects with obesity. The present work intends to investigate whether the zinc nutritional status is associated with hyperinsulinemia in obesity. A study was carried out in a group of obese children and adolescents (n=23) and compared to a control group (n=21), both between 7 and 14 yr of age. Software analyzed diet information from 3-d food records. Body composition was evaluated by body mass index (BMI), bioelectrical impedance, and skin-fold measurements. Zinc nutritional status was evaluated by Zn determination in plasma, erythrocyte, and 24-h urine, by atomic absorption spectrophotometry (lambda=213.9 nm). Insulin was measured by radioimmunoassay (Linco Res). Diets consumed by both groups had marginal concentrations of zinc. Zinc concentrations in plasma and erythrocytes were significantly lower in the obese group. Urinary zinc excretion and serum insulin were significantly higher in the same group, although the insulinemia and the parameters of zinc nutritional status were not significantly correlated. As a result, considering that zinc is part of the synthesis and secretion of this hormone, an assessment is necessary of the possible participation of the oligoelement in the mechanisms of insulin resistance, commonly present in obese patients.