ABSTRACT
Children born small for gestational age are known to be at increased risk for adult diseases such as hypertension, diabetes, and coronary heart disease. Oxidative stress is a common feature of these pathogenic conditions and can be the key link between size at birth and increased morbidity later in life. The purpose of this study was to analyze the parameters of lipoperoxidation and changes in antioxidant defense system as well as assess their relationship to birth weight. Concentrations of thiobarbituric-acid-reactive-substances and F2-isoprostanes, total antioxidant status, and the activity of both superoxide dismutase and glutathione peroxidase were measured in 65 children (33 boys, 32 girls; ages 8-13 y). Thiobarbituric-acid-reactive-substances and F2-isoprostane levels were significantly elevated in children born small for gestational age. Nevertheless, superoxide dismutase activity was significantly elevated in these children and the levels of both glutathione peroxidase activity and total antioxidant status were unchanged. Moreover, we found that systolic blood pressure was positively associated with thiobarbituric-acid-reactive-substances levels in race- and gender-adjusted models but not in a multivariable regression model. In conclusion, the current study revealed that there is evidence of oxidative stress in children born small for gestational age as supported by increased lipid peroxidation.
Subject(s)
Antioxidants/metabolism , Biomarkers , Infant, Small for Gestational Age/metabolism , Lipid Peroxidation , Oxidative Stress , Biomarkers/blood , Biomarkers/urine , Birth Weight , Blood Pressure , Brazil , Censuses , Child , Cohort Studies , Cross-Sectional Studies , Diabetes Mellitus/metabolism , Diabetes Mellitus/physiopathology , F2-Isoprostanes/urine , Female , Glutathione Peroxidase/blood , Humans , Hypertension/metabolism , Hypertension/physiopathology , Infant, Newborn , Infant, Small for Gestational Age/blood , Infant, Small for Gestational Age/urine , Lipids/blood , Male , Poverty Areas , Superoxide Dismutase/blood , Thiobarbituric Acid Reactive Substances/metabolism , Uric Acid/bloodABSTRACT
INTRODUÇÃO E OBJETIVOS: Os recém-nascidos de muito baixo-peso (RNMBP) têm necessidades nutricionais especiais. Existe uma tendência atual de se individualizar a oferta protéica para essas crianças. O objetivo do trabalho é determinar a utilidade da uréia sérica e urinária como indicadores da oferta protéica em RNMBP adequados (AIG) e pequenos para a idade gestacional (PIG). TIPO DE ESTUDO E LOCAL: Estudo prospectivo realizado no Berçário Anexo à Maternidade Instituto da Criança "Prof. Pedro de Alcântara" do Hospital das Clínicas, Departamento de Pediatria da Faculdade de Medicina, Universidade de São Paulo, Brasil. MÉTODOS: Setenta e dois RNMBP (oferta protéica média = 3,7 g/kg/dia) foram incluídos, em um estudo de coorte prospectivo, em dois grupos: AIG (n = 34) e PIG (n = 38). Amostras de sangue, coletas de urina de seis horas (Ur6h) e em amostras isoladas (AIUr) foram obtidas para determinação de uréia e creatinina após a 3ª semana de vida e duas semanas após. Análise estatística: teste t de Student, correlação de Pearson e regressão linear (p < 0,05). RESULTADOS: Não houve diferença entre os grupos quanto aos níveis de uréia sérica, uréia Ur6h e uréia AIUr, bem como entre as duas avaliações dentro de cada grupo. A uréia sérica correlacionou-se à uréia Ur6h nos RNAIG e nos PIG, bem como à uréia AIUr nos RNPIG. A uréia Ur6h correlacionou-se à uréia AIUr nos RNAIG e nos RNPIG. Não houve correlação entre a oferta protéica e a uréia sérica ou urinária. CONCLUSÕES: A uréia sérica e a urinária não refletiram a oferta protéica quando foram utilizadas ofertas médias de 3,7 g/kg/dia. Uréia AIUr pode ser tão confiável quanto uréia da urina coletada por períodos mais longos.
Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Dietary Proteins/metabolism , Energy Intake/physiology , Infant, Small for Gestational Age/metabolism , Infant, Very Low Birth Weight/metabolism , Urea/analogs & derivatives , Creatinine/blood , Creatinine/urine , Dietary Proteins/administration & dosage , Epidemiologic Methods , Gestational Age , Infant, Small for Gestational Age/blood , Infant, Small for Gestational Age/urine , Infant, Very Low Birth Weight/blood , Infant, Very Low Birth Weight/urine , Urea/blood , Urea/urineABSTRACT
CONTEXT AND OBJECTIVE: Very low birth weight (VLBW) infants have special nutritional needs. There is a current tendency to individualize their protein needs. The objective of this study was to determine the suitability of serum and urinary urea as indicators for protein intake in adequate-for-gestational-age (AGA) and small-for-gestational-age (SGA) VLBW infants. DESIGN AND SETTING: Prospective study in the nursery attached to the Maternity Ward of the "Prof. Pedro de Alcântara" Children's Institute, Hospital das Clínicas, Department of Pediatrics, Faculdade de Medicina da Universidade de São Paulo, Brazil. METHODS: Seventy-two VLBW infants (mean protein intake = 3.7 mg/kg/day) were enrolled in a prospective cohort study in two groups: AGA (n = 34) and SGA (n = 38). Blood samples, six-hour urine (6hUr) collections and urine sample tests (STUr) were obtained for urea and creatinine assays at three and five weeks of life. STATISTICAL ANALYSIS: Student's t test, Pearson correlation and linear regression (p < 0.05). RESULTS: There were no differences between groups for serum urea, 6hUr and STUr, or between two assessments within each group. Serum urea correlated with 6hUr in both AGA and SGA, and to STUr in SGA; 6hUr correlated with STUr in both AGA and SGA. There was no correlation between protein intake and serum or urine urea. CONCLUSIONS: Serum and urinary urea did not reflect protein intake when mean intakes of 3.7 g/kg/day were used. Sample tests of urinary urea can be as reliable as urea from urine collected over longer periods.