Avaliação da capacidade física de crianças nascidas prematuras com muito baixo peso

• Autor(a) principal: Tsopanoglou, Sabrina Pinheiro [UNIFESP]
• Data de Publicação: 2016
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=4264704; http://repositorio.unifesp.br/handle/11600/46453
• topic: Child; Preterm infant; Cardiopulmonary exercise test; Physical capacity; Aerobic capacity; Criança; Prematuro; Teste de exercício cardiopulmonar; Capacidade física; Capacidade aeróbica

Objectives: To compare aerobic capacity of children born prematurely with children born at term and to identify factors associated with aerobic capacity of these children during cardiopulmonary exercise test (CPET). Methods: Cross-sectional study with two groups of children aged 6-9 years: one group of children born prematurely with birth weight <1500g and followed at the Preterm out clinic of the Federal University of São Paulo. Children born at term composed the second group; brothers, friends or relatives of preterm children who did not presented clinical complications during neonatal period. Exclusion criteria were: congenital malformations, neuromuscular disorders, neurological, medical or developmental impairment that could compromise the results or safety of the child during the test and/or respiratory disease 15 days prior to testing. For CPET, it was adopted a quickly incremental symptom limited protocol with individualized load increase on treadmill. Variables measured were: oxygen pulse (PuO2), peak of heart rate (HR peak), percentage of maximum heart rate expected for age (% HR max), tidal volume/inspiratory capacity (VC/CI rest and peak), ventilatory equivalent for CO2 (VE/VCO 2 slope and lowest), oxygen consumption (VO2) peak and percentage of maximum predicted oxygen consumption for age (% VO2 max prev.), oxygen consumption at anaerobic threshold/anaerobic threshold (VO2 in LA), maximal oxygen and threshold of maximum percentage provided for oxygen-consuming for age ratio (VO2 @ LA/%VCO2 max. pred), Oxygen Uptake Efficiency Slope (OUES). The sample size calculation required 22 participants in each group, to evidence a difference of 7.3mL/kg/min. in VO2 between groups, considering alpha of 0.05 and beta of 0.80. Categorical variables were compared by chi-square or Fisher's exact test and numeric variables by the student t test or Mann-Whitney, according to their distribution evaluated by the Kolmogorov-Smirnov. Univariate and multiple linear regression analysis were applied to evaluate factors associated with aerobic capacity. Variables with clinical and statistical significance (p <0.2) detected by univariate regression were included in the multivariate model. Statistical analysis was performed using SPSS for Win / v.17.0, considering significant p <0.05. Results: Thirty-four preterm infants were included (gestational age 29.8 ± 2.5 weeks,birth weight 1131 ± 228g) and 32 term children. Among preterm children, 70.6% required mechanical ventilation and the length of stay in the unit neonatal was 61 ± 21 days. At inclusion in the study, both groups were similar in age, weight, height, body mass index and incidence of overweight/obesity, except for the z score for height/age (Preterm group: -0.35 ± 1.17 vs. Term group: 0.24 ± 0.96, p = 0.032). All parameters of aerobic capacity were similar in both groups. By multivariate linear regression: HR peak was positively associated with bronchopulmonary dysplasia and overweight/obesity; %Maximum heart rate was positively associated with broncopulmonary dysplasia, overweight/obesity; PuO2 was positively associated to the z-score for height/age and negatively to female; VO2 peak was positively associated with birth weight <1000 g, and negatively for female and overweight/obese. Conclusions: The parameters of aerobic capacity evaluated by the cardiopulmonary test were similar in both groups. Factors associated with aerobic capacity were female, broncopulmonary dysplasia and variables related to body growth, showing the influence of neonatal factors and postnatal growth on the aerobic capacity of children born prematurely.