Neuropsychomotor development and genomic stability associated to folate and blood iron levels in preschool children / Desenvolvimento neuropsicomotor e estabilidade genômica associados aos níveis de folato e ferro sanguíneos de pré-escolares

Abstract Objectives: to evaluate the neuropsychomotor development and the genomic stability associated to folate and blood iron levels in preschool children. Methods: a cross-sectional study in which evaluated the biochemical exams (complete hemogram, serum ferritin, iron and folate), neuropsychomotor development (Denver II Test) and genotoxicity (micronuclei cytome in buccal mucosa cells) of 55 children aging 36-59 months old. Student´s T test, Kruskal-Wallis and Pearson's or Spearman's correlation tests were applied with a significance level of p<0.05 for data analysis. Results: the prevalence of anemia was 1.8%. The Denver II test classified 32.7% of the children as normal and 67.3% were suspected of having a delay. The children suspected of having a delay presented a slight reduction on hemoglobin and hematocrit (p=0.05 and p=0.14), intermediate reduction on iron and folate (p=0.29 and p=0.23) and a notable reduction on ferritin (p=0.03). Folate and iron were significantly associated to the frequency of cells with DNA damages (p<0.05). The frequency of binucleated cells was positively associated to the Red Cell Distribution Width (RDW) (r=0.56; p=0.02) in children without a delay and negatively with folate (r=-0.334; p=0.047) in children with a delay. Conclusions: this study showed a low prevalence of anemia, but a high rate of children suspected of having a neuropsychomotor, possibly associated to low ferritin levels. Additionally, iron and folate were associated to DNA damage which may have contributed to the psychomotor development delay.

Resumo Objetivos: avaliar o desenvolvimento neuropsicomotor e a estabilidade genômica associados ao folato e ferro sanguíneos em pré-escolares. Métodos: estudo transversal, no qual avaliou-se exames bioquímicos (hemograma completo, ferritina sérica, ferro e folato), desenvolvimento neuropsicomotor (Teste Denver II) e genotoxicidade (citoma de micronúcleos em células bucais esfoliadas) de 55 crianças com 36-59 meses de idade. Para a análise dos dados, empregou-se os testes T de Student, Kruskal-Wallis e correlação de Pearson ou Spearman, com nível de significância de p<0,05. Resultados: a prevalência de anemia foi de 1,8%. Pelo teste de Denver II foram classificadas 32,7% das crianças como normais e 67,3% como suspeita de atraso. As crianças com suspeita de atraso apresentaram pequena redução no hematócrito e hemoglobina (p=0,05 e p=0,14), redução intermediária de ferro e folato (p=0,29 e p=0,23) e redução marcante de ferritina (p=0,03). Ferro e folato associaram-se significativamente com a frequência de células com lesões no DNA (p<0,05). A frequência de células binucleadas associou-se positivamente com Red Cell Distribution Width (RDW) (r=0,56; p=0,02), nas crianças sem atraso e negativamente com folato (r=-0,33; p=0,05), nas crianças com atraso. Conclusões: este estudo mostrou baixa prevalência de anemia, mas elevada taxa de crianças com suspeita de atraso neuropsicomotor, possivelmente associada com baixos níveis de ferritina. Ademais, observou-se associação entre ferro e folato com dano no DNA, o que pode ter contribuído para o atraso neuropsicomotor.

Vitamin C intake reduces the cytotoxicity associated with hyperglycemia in prediabetes and type 2 diabetes.

Hyperglycemia leads to the formation of free radicals and advanced glycation end-products (AGEs). Antioxidants can reduce the level of protein glycation and DNA damage. In this study, we compared the levels of vitamin C intake, which is among the most abundant antioxidants obtained from diet, with the levels of fasting plasma glucose (FPG), glycated hemoglobin (A1C), DNA damage, and cytotoxicity in prediabetic subjects and type 2 diabetic subjects. Our results indicated that there was no significant correlation between FPG or A1C and DNA damage parameters (micronuclei, nucleoplasmic bridges, and nuclear buds). FPG and A1C correlated with necrosis (r = 0.294; P = 0.013 and r = 0.401; P = 0.001, resp.). Vitamin C intake correlated negatively with necrosis and apoptosis (r = -0.246; P = 0.040, and r = -0.276; P = 0.021, resp.). The lack of a correlation between the FPG and A1C and DNA damage could be explained, at least in part, by the elimination of cells with DNA damage by either necrosis or apoptosis (cytotoxicity). Vitamin C appeared to improve cell survival by reducing cytotoxicity. Therefore, the present results indicate the need for clinical studies to evaluate the effect of low-dose vitamin C supplementation in type 2 diabetes.

DNA damage in children and adolescents with cardiovascular disease risk factors.

The risk of developing cardiovascular disease (CVD) is related to lifestyle (e.g. diet, physical activity and smoking) as well as to genetic factors. This study aimed at evaluating the association between CVD risk factors and DNA damage levels in children and adolescents. Anthropometry, diet and serum CVD risk factors were evaluated by standard procedures. DNA damage levels were accessed by the comet assay (Single cell gel electrophoresis; SCGE) and cytokinesis-blocked micronucleus (CBMN) assays in leukocytes. A total of 34 children and adolescents selected from a population sample were divided into three groups according to their level of CVD risk. Moderate and high CVD risk subjects showed significantly higher body fat and serum CVD risk markers than low risk subjects (P<0.05). High risk subjects also showed a significant increase in DNA damage, which was higher than that provided by low and moderate risk subjects according to SCGE, but not according to the CBMN assay. Vitamin C intake was inversely correlated with DNA damage by SCGE, and micronucleus (MN) was inversely correlated with folate intake. The present results indicate an increase in DNA damage that may be a consequence of oxidative stress in young individuals with risk factors for CVD, indicating that the DNA damage level can aid in evaluating the risk of CVD.

Iron intake, red cell indicators of iron status, and DNA damage in young subjects.

OBJECTIVE: This study evaluated the association between primary DNA damage and chromosomal damage with iron intake and red blood cell parameters of iron status in a sample of healthy children and adolescents from a low-socioeconomic community. METHODS: The level of primary DNA damage was assessed using an alkaline comet assay and the level of chromosomal damage was assessed using the cytokinesis-block micronucleus assay. A automated complete blood count was used to evaluate red blood cell status. The intake of iron was measured using a food-recall questionnaire. RESULTS: According to hemoglobin levels, only 1 of the 30 subjects evaluated was anemic. Nevertheless, 43% of the sampled subjects showed decreased mean corpuscular volume in addition to an increased amount of primary DNA damage (P < 0.05). Mean corpuscular volume was negatively correlated with primary DNA damage (r = -0.429, P = 0.020) but not with chromosomal damage. The association between iron and primary DNA damage showed a U-shaped curve, indicating that an intake of approximately 15 mg of iron per day (up to two-fold of the dietary recommended intake) could minimize primary DNA damage in this age group. The frequency of micronuclei and nucleoplasmic bridges, indicators of chromosomal breakage/loss and chromosomal end-fusions, respectively, showed a negative correlation with iron intake. These results indicate that an intake of iron >15 mg/d could increase genomic stability in binucleated lymphocytes of the same group. CONCLUSION: An intake of iron ≥ 15 mg/d can decrease DNA damage in young subjects.