Reserva de ferro reduzida em crianças com Transtorno do Espectro Autista

Abstract

Iron deficiency can be determined by stages of depletion, iron deficiency and anemia. Hemoglobin (Hb) is used to diagnose anemia, whereas serum ferritin concentration is used to estimate stored iron content. Iron depletion is indicated by values below 12μg.L-1 in children under 5 years and below 15μg.L-1 for children between 5 and 12 years. However, ferritin should be above 30 μg.L-1 since values below 15 μg.L-1 indicate the presence of physiological repercussions, especially in the brain. In the general pediatric population, iron deficiency is known to be very common, but is even more common in childhood developmental disorders, such as Autistic Spectrum Disorder (ASD). The aim of the study was to investigate serum ferritin concentration in children and adolescents with ASD. A cross-sectional study was conducted with children and adolescents between 3 and 18 years of age diagnosed with ASD. Those diagnosed with neuropathies and congenital heart disease, taking supplements, and who did not collect blood were excluded. Fifty-seven participants between 3 and 18 years old were evaluated. Anthropometry was performed and those responsible answered a standardized questionnaire on sociodemographic characteristics and clinical data. The variables analyzed were maternal education (years); age of child / adolescents (years); gender (male and female), skin color (white and non-white), body mass index (BMI) in z-score for age, antipsychotic use (yes or no). The outcome variables were ferritin ng.ml-1 and Hb g.dl-1. Hb values below 11.5 g.dL-1 for children aged 2 to 12 years and below 12.0 g.dL-1 for those older than 12 years were considered anemia. A reduced iron reserve was considered to be a ferritin concentration below 30 ng.mL-1. Regarding exposure analyzes in relation to the outcome, the comparison between two or three categories was performed with nonparametric tests. The independent association between each study age group and ferritin and Hb concentration was tested using adjusted linear regression analysis. Adjustment variables were mother's education, age, gender, skin color, use of antipiscotics and overweight. We considered a statistically significant difference p <0.05. The average age was 8.5 ± 3.1 years, most of them white, with antipsychotic and overweight. Maternal education was 9 years or older (63.2%), the prevalence of reduced iron stores and anemia was 21.1% and 7.0%, respectively. Adjusted analysis indicated that 17% of serum ferritin concentration was attributed to maternal education and age. Iron stores were lower among children ≤ 5 years old when compared to children over 5 years old. It was concluded that iron stores were reduced in children with autism spectrum aged ≤5 years, despite the absence of anemia.