Okuro Renata Tiemi, de Oliveira Ribeiro Maria Angela Gonçalves, Ribeiro José Dirceu, Minsky Rafaela Coelho, Schivinski Camila Isabel Santos
Faculty of Medical Sciences, State University of Campinas (UNICAMP), Brazil.
UNICAMP and the Pulmonary Function Laboratory (LAFIP) at CIPED (Center for Investigation in Pediatrics), Department of Pediatrics, Faculty of Medical Sciences (FCM)/UNICAMP, Brazil.
Respir Care. 2017 Mar;62(3):324-332. doi: 10.4187/respcare.04625. Epub 2017 Jan 3.
Cystic fibrosis is a multi-systemic disease related to reduced functional capacity. The distance covered in the 6-min walk test (6MWT) has been known to assess functional capacity, but little is known about other indexes that can be derived. We sought to compare the performance during the 6MWT and the estimated indexes of functional capacity from the 6MWT between subjects with cystic fibrosis (CF) and healthy individuals as well as to assess the relationship among these indexes and disease severity, pulmonary function, and nutritional status in CF.
This cross-sectional study was carried out at a university referral center for CF. It included a group of 55 non-oxygen-dependent CF subjects (CF group) with no acute pulmonary exacerbations and a group of 185 healthy controls (control group). All subjects were submitted to 6MWT and anthropometrics measurements.
Regarding performance during the 6MWT, the mean values of work, physiological cost index, average velocity, and 6-min walk distance (6MWD) were significantly lower in the CF group than in the control group (work: 21,690.58 ± 10,427.77 vs 26,057.51 ± 11,228.49 m × kg [ = .007]; physiological cost index: 0.31 ± 0.19 vs 0.37 ± 0.17; average velocity: 94.71 ± 12.89 vs 104.55 ± 9.13 m/min [ < .001]; and 6MWD: 568.02 ± 76.31 m versus 627.54 ± 54.81 m [ < .001]). Subjects with less severe CF had higher 6MWD, work, and average velocity during the 6MWT, compared with subjects with more severe CF ( = .008, = .01, and = .007, respectively). There was a correlation between 6MWD, work, average velocity, and disease severity and pulmonary function.
Considering the importance of standard measure (6MWD) the in 6MWT, alternative indexes can be useful as complementary outcomes and to provide a better understanding of limiting factors of exercise response in children and adolescents with CF.
囊性纤维化是一种与功能能力下降相关的多系统疾病。6分钟步行试验（6MWT）中的步行距离已被用于评估功能能力，但对于可得出的其他指标知之甚少。我们试图比较囊性纤维化（CF）患者与健康个体在6MWT期间的表现以及从6MWT得出的功能能力估计指标，并评估这些指标与CF患者疾病严重程度、肺功能和营养状况之间的关系。
这项横断面研究在一家大学CF转诊中心进行。它包括一组55名无急性肺部加重的非吸氧依赖型CF患者（CF组）和一组185名健康对照者（对照组）。所有受试者均接受6MWT和人体测量。
关于6MWT期间的表现，CF组的功、生理成本指数、平均速度和6分钟步行距离（6MWD）的平均值显著低于对照组（功：21,690.58±10,427.77 vs 26,057.51±11,228.49米×千克[P =.007]；生理成本指数：0.31±0.19 vs 0.37±0.17；平均速度：94.71±12.89 vs 104.55±9.13米/分钟[P <.001]；6MWD：568.02±76.31米对627.54±54.81米[P <.001]）。与病情较重的CF患者相比，病情较轻的CF患者在6MWT期间的6MWD、功和平均速度更高（分别为P =.008、P =.01和P =.007）。6MWD、功、平均速度与疾病严重程度和肺功能之间存在相关性。
考虑到标准测量指标（6MWD）在6MWT中的重要性，替代指标可作为补充结果，并有助于更好地理解CF儿童和青少年运动反应的限制因素。
