Trabalho externo avaliado por meio do teste de caminhada de seis minutos em crianças em idade escolar

Abstract

The Six-Minute Walk Test (6MWT) is widely used in the evaluation of the functional and exercise capacity of healthy and sick children, being an easy test, low cost and with high clinical applicability. The distance covered in the 6MWT (6MWTdistance) is the endpoint used in the interpretation of the test result. However, the literature indicates that the work measurement in the 6MWT (6MWTwork) seems to represent better the performance of children. Thus, the objectives of this thesis were to characterize the functional capacity of school-age children through the measure 6MWTwork; to verify if the 6MWTwork is able to discriminate the functional capacity of school-age children in relation to the 6MWTdistance; and to verify whether age, gender, nutritional status, height, physical activity practice and heart rate (HR) delta (HRfinal 6MWT minus HR rest) determine 6MWTw in school-aged children. It was an exploratory cross-sectional study through a secondary analysis of data from two centers of a multicenter study titled "Reference values for Six-minute Walk Test in healthy children in Brazil." The sample was composed of 319 children of both sexes between 7 and 12 years of age and obtained at the Federal Universities of Minas Gerais and of Uberlândia. The first article contemplated the first two objectives and the mean of the 6MWTdistance of Brazilian children in this age group (579 meters) was considered for the analysis related to 6MWTwork. The results showed that the 6MWTwork correctly classified, on average, 71.2% of the variation between the groups analyzed, 73.6% of the children walking below 579m and 58% of those walking above 579 m (Cut-off point of the discriminant function: 192211.22 Joules, p <0.0001, canonical correlation function of 0.321). The majority of children of both sexes, from the 10 years of age, presented expected values of 6MWTwork given the cut-off point of the discriminant function. The second article was developed to meet the third objective.The analyzes showed that age, height, nutritional status, physical activity practice and HR delta were positively and statistically significant with 6MWTwork (p < 0.0001). Multiple linear regression analysis showed that age, height, nutritional status and delta of the HR explained 87% of the 6MWTwork variation for the children evaluated (p = 0.0001). In view of these results, it can be concluded that the 6MWTwork measure is able to discriminate the functional capacity of school-age children, and that age, height, nutritional status and delta of the HR determine this measure evaluated in these individuals. Therefore to state that 6MWTwork can be used in clinical practice to add value to the interpretation of the results obtained in the 6MWT in children.