Six-minute walking test in children with ESRD: discrimination validity and construct validity

Malnutrition Patterns in Children with Chronic Kidney Disease

Malnutrition is frequent in children with chronic kidney disease (CKD). Apart from undernutrition and protein energy wasting (PEW), overnutrition prevalence is rising, resulting in fat mass accumulation. Sedentary behavior and unbalanced diet are the most important causal factors. Both underweight and obesity are linked to adverse outcomes regarding renal function, cardiometabolic risk and mortality rate. Muscle wasting is the cornerstone finding of PEW, preceding fat loss and may lead to fatigue, musculoskeletal decline and frailty. In addition, clinical data emphasize the growing occurrence of muscle mass and strength deficits in patients with fat mass accumulation, attributed to CKD-related wasting processes, reduced physical activity and possibly to obesity-induced inflammatory diseases, leading to sarcopenic obesity. Moreover, children with CKD are susceptible to abdominal obesity, resulting from high body fat distribution into the visceral abdomen compartment. Both sarcopenic and abdominal obesity are associated with increased cardiometabolic risk. This review analyzes the pathogenetic mechanisms, current trends and outcomes of malnutrition patterns in pediatric CKD. Moreover, it underlines the importance of body composition assessment for the nutritional evaluation and summarizes the advantages and limitations of the currently available techniques. Furthermore, it highlights the benefits of growth hormone therapy and physical activity on malnutrition management.

Comparison of effectiveness of Nintendo Wii-based exergaming and home-based fun video exercises in pediatric patients with chronic kidney disease

Functional capacity and quality of life (QoL) are reduced in children and adults with chronic kidney disease (CKD). Aerobic, strengthening exercises, and exergames are reported as effective in the treatment of symptoms associated with CKD. Unlike adult patients, there are insufficient studies investigating the effects of exercise on disease-related symptoms in pediatric CKD. This study aimed to compare the effects of Nintendo Wii-based exergaming and home-based fun video exercises on functional capacity, muscle strength, physical activity (PA), depression, fatigue, and QoL in pediatric patients with CKD. Twenty-three pediatric patients with CKD were included in the study and randomized to group I (Nintendo Wii Fit) and group II (home-based fun video exercises). Patients in both groups underwent exercise programs twice per week for 6 weeks. Functional capacity, muscle strength, PA, QoL, fatigue, and depression of the patients were evaluated before and after the treatments. Sixteen patients completed the study. After treatment, significant differences were observed in both groups on 6MWT, muscle strength, average daily steps, PedsQoL Child Self-Report PHSS, and the Visual Fatigue Scale. Left knee flexor muscle strength and average step counts were found to be superior in group I. Both exergaming and home-based fun video exercises provide positive effects on functional capacity, muscle strength, fatigue, PA, depression, and QoL in pediatric patients with CKD. We think that these exercise methods can help to protect physical and mental health of patients and should be included in treatment from the early stages of the disease.

Physical performance capacity after pediatric kidney transplant and clinical parameters associated with physical performance capacity

BACKGROUND

History of chronic kidney disease and kidney transplantation is known to influence physical performance capacity. The aim of this study was to compare the physical performance of pediatric kidney transplant recipients to healthy controls and to find possible correlations between clinical parameters and physical performance capacity.

METHODS

Twenty-four pediatric kidney transplant recipients (62.5% boys) were tested at a median age of 10.8 years. Physical performance capacity was tested with a test set including six different components assessing muscle endurance, strength, speed, and flexibility. The control group consisted of 273 healthy age-matched schoolchildren. Clinical parameters were collected as part of routine follow-up protocol. The majority of patients (62.5%) had congenital nephrotic syndrome of Finnish type (CNS) as primary diagnosis, and therefore, the results of CNS recipients were compared to the other disease groups.

RESULTS

The physical performance capacity in pediatric kidney transplant recipients was lower compared to healthy controls. Surprisingly, no statistically significant correlation was found between graft function and physical performance capacity. The CNS patients scored worse than patients with other diagnoses in all test domains except for sit-and-reach and shuttle run, but the differences did not reach statistical significance.

CONCLUSION

The physical performance of pediatric kidney transplant recipients is reduced, especially in those with congenital nephrotic syndrome. Clinical parameters, including graft function, did not predict physical performance capacity, suggesting that the reduced physical performance seems to be of multivariable cause. A higher resolution version of the Graphical abstract is available as Supplementary information.

Physical activity and the 'pediatric inactivity triad' in children living with chronic kidney disease: a narrative review

The ‘paediatric inactivity triad’ (PIT) framework consists of three complex inter-related conditions that influence physical inactivity and related health risks. In those living with chronic kidney disease (CKD), a multi-factorial milieu of components likely confound the PIT elements, resulting in a cycle of decreased physical functioning and reduced physical activity. In this review, we explore and summarize previous research on each of the three principal PIT components (exercise deficit disorder, dynapenia, and physical illiteracy) in the pediatric CKD population. We found those living with CKD are significantly physically inactive compared to their peers. Physical inactivity occurs early in the disease process and progressively gets worse as disease burden increases. Although physical activity appears to increase post-transplantation, it remains lower compared to healthy controls. There is limited evidence on interventions to increase physical activity behaviour in this population, and those that have attempted have had negligible effects. Studies reported profound reductions in muscle strength, physical performance, and cardiorespiratory fitness. A small number of exercise-based interventions have shown favourable improvements in physical function and cardiorespiratory fitness, although small sample sizes and methodological issues preclude the generalization of findings. Physical activity must be adapted and individualized to the needs and goals of the children, particularly those with acute and chronic medical needs as is the case in CKD, and further work is needed to define optimal interventions across the life course in this population if we aim to prevent physical activity declining further.

Testes funcionais validados em indivíduos hospitalizados e não hospitalizados: revisão sistemática

Objetivo: Realizar uma revisão sistemática sobre os testes funcionais validados em diferentes perfis de indivíduos hospitalizados e não hospitalizados e avaliar as evidências psicométricas para confiabilidade e validade. Métodos: Trata-se de uma revisão sistemática. Foram utilizadas as bases de dados EMBASE, MEDLINE, Lilacs e SciELO com as palavras-chave Functional Tests (Walk Test, Gait Speed Test, Chair Stand Test, Timed Up And Go, Step Test),Validation Studies as Topic e sinônimos. Foram incluídos estudos de validação de testes funcionais em indivíduos hospitalizados ou não hospitalizados que utilizaram os critérios de validade e/ou confiabilidade e relacionaram os testes a diferentes variáveis. Esses artigos poderiam ser observacionais longitudinais ou de corte transversal ou estudos de validação que utilizaram dados de ensaios clínicos. Foram excluídos os artigos que não apresentaram características importantes da amostra e a descrição do teste. Resultados: A pesquisa resultou em 36.150 artigos, e 89 foram incluídos. Os estudos foram organizados em tabelas com informações como autor, ano; critérios de validação; amostra; teste; variáveis associadas; resultados. A qualidade dos artigos foi avaliada por meio da Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Conclusão: Os testes funcionais são válidos e confiáveis para a avaliação de indivíduos hospitalizados e não hospitalizados, estando associados à força muscular, capacidade de caminhar, controle postural, atividades de vida diária, risco de quedas, hospitalização e mortalidade.

Six minute walk distance and reference values in healthy Italian children: A cross-sectional study

The 6-minute walking test (6MWT) is a simple assessment tool to evaluate exercise capacity. The result of the test is the distance that a subject can walk at a constant and normal pace within 6 minutes (6MWD) and reflects the aerobic/fitness performance related to walking function. Use of 6MWT has been relevant to assess exercise tolerance either in healthy children or in patients with, heart, lung and metabolic diseases. Our aim was to find 6MWT reference values in healthy Italian children. The 6MWT was performed in 5614 children aged 6–11 years recruited from primary Italian schools. Age related reference percentiles of the covered distance were gender-modeled. A linear and quadratic regression model was used to predict 6MWT performance. Males walked longer distances than females, respectively 598.8±83.9 m vs 592.1±77.6 m (p = 0.0016). According to the regression analysis, 6MWD was positively related to age, gender and height, while it was negatively related to body weight [(6MWD = -160.16 + 93.35× age (years) -4.05× age²(years) +7.34× gender (m) +2.12× weight (kg) −2.50× height (cm)]. Reference values were established for the 6MWT in healthy children. The age related 6MWD percentiles provided a useful tool in the assessment of capacity in 6–11 year children, in fact they may be helpful to evaluate the effect of a given treatment or rehabilitation program and represent a feasible measure as to prevention within the primary school context. It was found a substantial difference from other countries for 6mwd values. In our study, factors such as age, weight and height were relevant for the prediction of 6MWD, similarly to other studies. Therefore, these variables should be taken into account in context of exercise performance.

Small effort, high impact: Focus on physical activity improves oxygen uptake (VO2peak ), quality of life, and mental health after pediatric renal transplantation

This study estimates the effects on peak oxygen uptake (VO2 peak ), QoL, and mental health after the introduction of an adjusted post-transplant follow-up program, that is, early physiotherapy and focus on the importance of physical activity. VO2 peak was measured by a treadmill exercise test in 20 renal-transplanted children on the adjusted post-transplant follow-up and compared with a group of 22 patients investigated in a previously, before the implementation of our new follow-up routines. PedsQL and The Strengths and Difficulties Questionnaire (SDQ) were used to assess QoL and mental health in 45 patients on the new as compared to 32 patients on the previous follow-up strategy. The patients exposed to early physiotherapy and a higher focus on physical activity had significantly higher VO2 peak (44.3 vs 33.5 mL kg-1  min-1 , P = .031) in addition to improved QoL (P = .003) and mental health scores (P = .012). The cardiovascular risk profile was similar in both groups aside from significantly higher triglycerides in the present cohort. Small efforts as early physiotherapy and increased focus on physical activity after pediatric renal transplantation have significant impact on cardiorespiratory fitness, QoL, and mental health. The importance of physical activity should therefore be emphasized in follow-up programs.

Reference Values for the Six-Minute Walk Test in Healthy Children and Adolescents: a Systematic Review

Objective

The aim of the study is to compare the available reference values and the six-minute walk test equations in healthy children/adolescents. Our systematic review was planned and performed in accordance with the PRISMA guidelines. We included all studies that established reference values for the six-minute walk test in healthy children/adolescents.

Methods

To perform this review, a research was performed in PubMed, EMBASE (via SCOPUS) and Cochrane (LILACS), Bibliographic Index Spanish in Health Sciences, Organization Collection Pan-American Health Organization, Publications of the World Health Organization and Scientific Electronic Library Online (SciELO) via Virtual Health Library until June 2015 without language restriction.

Results

The initial research identified 276 abstracts. Twelve studies met the inclusion criteria and were fully reviewed and approved by both reviewers. None of the selected studies presented sample size calculation. Most of the studies recruited children and adolescents from school. Six studies reported the use of random samples. Most studies used a corridor of 30 meters. All studies followed the American Thoracic Society guidelines to perform the six-minute walk test. The walked distance ranged 159 meters among the studies. Of the 12 included studies, 7 (58%) reported descriptive data and 6 (50%) established reference equation for the walked distance in the six-minute walk test.

Conclusion

The reference value for the six-minute walk test in children and adolescents ranged substantially from studies in different countries. A reference equation was not provided in all studies, but the ones available took into account well established variables in the context of exercise performance, such as height, heart rate, age and weight. Countries that did not established reference values for the six-minute walk test should be encouraged to do because it would help their clinicians and researchers have a more precise interpretation of the test.

Six-minute walk test in children and adolescents with renal diseases: tolerance, reproducibility and comparison with healthy subjects

OBJECTIVES

To evaluate exercise tolerance and the reproducibility of the six-minute walk test in Brazilian children and adolescents with chronic kidney disease and to compare their functional exercise capacities with reference values for healthy children.

METHODS

This cross-sectional study assessed the use of the six-minute walk test in children and adolescents aged 6-16 with stage V chronic kidney disease. For statistical analysis of exercise tolerance, including examinations of correlations and comparisons with reference values, the longest walked distances were considered. The reproducibility of the six-minute walk test was assessed using intraclass correlation coefficients.

RESULTS

A total of 38 patients (14 females and 24 males) were evaluated, including 5 on peritoneal dialysis, 12 on hemodialysis and 21 who had undergone renal transplantation, with a median age of 11.2 years (6.5-16). The median walked distance was 538.5 meters (413-685) and the six-minute walk test was found to be reproducible. The walked distance was significantly correlated with age (r=0.66), weight (r=0.76), height (r=0.82), the height Z score (r=0.41), hemoglobin (r=0.46), hematocrit (r=0.47) and post-test systolic blood pressure (r=0.39). The chronic kidney disease patients predicted walked distance was 84.1% of the reference value according to age, 90.6% according to age-corrected height and 87.4% according to a predictive equation.

CONCLUSIONS

The stage V chronic kidney disease patients had a significantly decreased functional exercise capacity, as measured by the six-minute walk test, compared with the healthy pediatric reference values. In addition, the six-minute walk test was shown to be well tolerated, reliable and applicable as a low-cost tool to monitor functional exercise capacity in patients with renal disease.

Reliability and validity of the 6-min walk test in adults and seniors with intellectual disabilities

INTRODUCTION

Adults with intellectual disabilities (ID) have significantly lower rates of physical activity and fitness than adults without ID. The 6-min walk test (6 MWT) is an inexpensive and simple way to test mobility and submaximal work capacity.

PURPOSE

To evaluate the test-retest reliability and validity of the 6 MWT in adults and seniors with ID and explore factors contributing to the 6 MWT distance (6 MWD).

METHODS

46 participants with mild, moderate and severe ID levels (age=41 ± 11 years) performed the 6 MWT three times (T1; T2; T3) to determine test-retest reliability. To test validity, peak oxygen uptake (VO2 peak) was measured using a treadmill protocol. To analyze factors contributing to the 6 MWD, sex, height, fat mass % and fat free mass %, ID level, isometric leg strength and relative VO2 peak were also measured.

RESULTS

The walking distances for T1, T2 and T3 were 460.3 ± 76.9; 489.4 ± 81.2 and 491.4 ± 77.9 m, respectively. The 6 MWDs between T1-T2 and T1-T3 were significantly different (p<0.001), but T2 and T3 were not different. The intraclass correlation coefficient between T2 and T3 was 0.96 indicating high reliability. Relative VO2 peak and isometric leg strength significantly contributed to the 6 MWD (R(2)=0.55).

CONCLUSIONS

The 6 MWT is an easy, inexpensive, reliable and valid test in adults and seniors with ID. Familiarization is necessary to obtain reliable values. Relative VO2 peak and leg strength have significant impact on the distance walked.

Pilot evaluation of physical and psychological effects of a physical trek programme including a dog sledding expedition in children and teenagers with cancer

AIM OF THE STUDY

To evaluate the feasibility and to measure the effects of a six-week-long adapted physical activity programme (APAP), including 5 days of intense dog sledding, on the physical and psychological health of children and adolescents treated for cancer.

METHODS

Eleven children and teenagers (4 girls, 7 boys; mean age 14.3 ± 2.9 years) participated in this monocentric pilot programme of adapted physical activities from February 2013 to March 2013. Seven were still on treatment. The programme lasted 6 weeks. A series of physical tests and psychological questionnaires were carried out before and after the programme.

RESULTS

All children and teenagers completed the full programme. An improvement in all physical and psychological parameters was observed. Statistically significant differences were observed for global self-esteem (6.2 ± 2.1 to 7.7 ± 1.8; p = 0.02), perceived sport competence (5.3 ± 3.2 to 7.4 ± 2; p = 0.02) and perceived physical strength (5.6 ± 2.5 to 7.1 ± 1.8; p = 0.001). Regarding physical tests, the physical training led to statistically significant improvement for sit-ups (13.8 ± 2.6 to 21.75 ± 5.4; p = 0.01), muscle tone (76 ± 23.7 to 100 ± 22.9; p = 0.01), and resting heart rate (96.1 ± 3.2 to 91.6 ± 4.5; p = 0.03).

CONCLUSION

This programme is feasible in children and adolescents even during their oncologic treatment. During the 6-week programme, children and adolescents improved their physical and psychological health, and the putative benefits of the APAP are discussed. A larger randomised trial started in 2014.

Walking capacity of children with clubfeet in primary school: something to worry about?

Although the main aim of clubfoot correction is to create a foot without limitations in daily activities and sport, studies on the walking capacity of children with corrected clubfeet are rare. In this cross-sectional study, the outcome of the six-minute walking test in 44 children with clubfeet (16 unilateral and 28 bilateral, mean age 8.57±2.45 years) was compared with the reference values of Geiger, clinical status measured with the Clubfoot Assessment Protocol (CAP), and regression analysis used to calculate which CAP subgroup predicts walking capacity. The mean walking capacity was decreased to 79% (P<0.001) and was not influenced by unilaterality or bilaterality (P=0.437). The subgroup CAP morphology was a significant predictor (R=0.103; P=0.034). Knowing that walking capacity is only slightly decreased can help adjust expectations and set goals for training.

Impact of chronic kidney disease on quality of life, lung function, and functional capacity

OBJECTIVES

To evaluate the impact of the chronic kidney disease (CKD) on quality of life, from the children's and their parents' perspective, respiratory muscle strength, lung function, and functional capacity in children and adolescents.

METHOD

Cross-sectional study of children with CKD aged 8 to 17 years. Those incapable of taking the tests were excluded. After an interview, quality of life by Pediatric Quality of Life Inventory) (PedsQL(TM)), muscular strength, pulmonary function tests, and the 6-minute walking test (6MWT) were applied. Student's t-test, ANOVA (difference in means), and Pearson's coefficient of correlation were used. The level of significance was set at 5%.

RESULTS

Of the 40 patients, the mean distance walked at the 6MWT was 396 meters, and the mean final score at the quality of life test as perceived by the children and parents was 50.9 and 51, respectively. From the children's perspective, the transplanted patients had a higher quality of life score when compared to those undergoing hemodialysis (p<0.001); those who practiced physical activity had better quality of life when compared to the sedentary children (p<0.001). From the children's and the parents' perspectives, the male gender had a higher quality of life score (p<0.05). There was a positive correlation between the distance walked at the 6MWT and age, height, final PedsQL(TM), forced vital capacity (FVC), and forced expiratory volume in the first second (FEV1), as well as a negative correlation between FEV1/FVC and the distance walked.

CONCLUSION

A significant reduction in the quality of life and the functional capacity was observed in children with CKD, influenced by the type of treatment, gender, and sedentary life style.

Psychometric properties of 2-minute walk test: a systematic review

OBJECTIVE

To systematically review the psychometric evidence on the 2-minute walk test (2MWT).

DATA SOURCES

Electronic searches of databases including MEDLINE, CINAHL, Academic Search Premier, SPORTDiscus, PsycINFO, EMBASE, the Cochrane Library, and DARE were done until February 2014 using a combination of subject headings and free texts.

STUDY SELECTION

Studies were included if psychometric properties of the 2MWT were (1) evaluated; (2) written as full reports; and (3) published in English language peer-reviewed journals.

DATA EXTRACTION

A modified consensus-based standard for the selection of health measurement instruments checklist was used to rate the methodological quality of the included studies. A quality assessment for statistical outcomes was used to assess the measurement properties of the 2MWT.

DATA SYNTHESIS

Best-evidence synthesis was collated from 25 studies of 14 patient groups. Only 1 study was found that examined the 2MWT in the pediatric population. The testing procedures of the 2MWT varied across the included studies. Reliability, validity (construct and criterion), and responsiveness of the 2MWT also varied across different patient groups. Moderate to strong evidence was found for reliability, convergent validity, discriminative validity, and responsiveness of the 2MWT in frail elderly patients. Moderate to strong evidence for reliability, convergent validity, and responsiveness was found in adults with lower limb amputations. Moderate to strong evidence for validity (convergent and discriminative) was found in adults who received rehabilitation after hip fractures or cardiac surgery. Limited evidence for the psychometric properties of the 2MWT was found in other population groups because of methodological flaws.

CONCLUSIONS

There is inadequate breadth and depth of psychometric evidence of the 2MWT for clinical and research purposes-specifically, minimal clinically important changes and responsiveness. More good-quality studies are needed, especially in the pediatric population. Consensus on standardized testing procedures of the 2MWT is also required.

Intradialytic cycling in children and young adults on chronic hemodialysis

BACKGROUND

Intradialytic exercise has been poorly investigated in pediatric patients on chronic hemodialysis (HD). The aim of this study was to assess the acceptability, safety and efficacy of intradialytic exercise in children and young adults on HD.

METHODS

The intradialytic exercise program consisted of 30-min sessions of intra-HD exercise using a cycloergometer two to three times a week for 3 months. Study endpoints were the 6-min walking test (6MWT) distances, lung function, number of stands in the chair test, lower extremity strength (LES), anthropometry, dietary intake, dialysis adequacy, incidence of symptomatic sessions, biochemistry and left ventricular mass index.

RESULTS

Ten pediatric patients with a median age of 15.3 (range 9.1-24.2) years were enrolled. Two of these underwent kidney transplantation; the remaining eight completed the study and adapted well to the exercise program. At the end of the 3-month study period, all patients had significantly improved results for the 6MWT (+4.9 %; p < 0.05), chair test (+19 %; p < 0.05) and LES (+29.3 %; p < 0.05). Pre-HD albumin, creatinine and total protein levels and post-HD creatinine levels had also significantly improved. The incidence of symptomatic sessions did not increase during the study period. No adverse events occurred.

CONCLUSIONS

Based on our results, we conclude that a 30-min exercise program of intradialytic cycling is feasible for the majority of pediatric patients on chronic HD and will be well accepted. Such an exercise program can lead to a significant improvement in the exercise capacity of this patient population.

The six-minute walk test in chronic pediatric conditions: a systematic review of measurement properties

BACKGROUND

The Six-Minute Walk Test (6MWT) is increasingly being used as a functional outcome measure for chronic pediatric conditions. Knowledge about its measurement properties is needed to determine whether it is an appropriate test to use.

PURPOSE

The purpose of this study was to systematically review all published clinimetric studies on the 6MWT in chronic pediatric conditions.

DATA SOURCES

The databases MEDLINE, EMBASE, CINAHL, PEDro, and SPORTDiscus were searched up to February 2012.

STUDY SELECTION

Studies designed to evaluate measurement properties of the 6MWT in a chronic pediatric condition were included in the systematic review.

DATA EXTRACTION

The methodological quality of the included studies and the measurement properties of the 6MWT were examined.

DATA SYNTHESIS

A best evidence synthesis was performed on 15 studies, including 9 different chronic pediatric conditions. Limited evidence to strong evidence was found for reliability in various chronic conditions. Strong evidence was found for positive criterion validity of the 6MWT with peak oxygen uptake in some populations, but negative criterion validity was found in other populations. Construct validity remained unclear in most patient groups because of methodological flaws. Little evidence was available for responsiveness and measurement error. Studies showed large variability in test procedures despite existing guidelines for the performance of the 6MWT.

LIMITATIONS

Unavailability of a specific checklist to evaluate the methodological quality of clinimetric studies on performance measures was a limitation of the study.

CONCLUSIONS

Evidence for measurement properties of the 6MWT varies largely among chronic pediatric conditions. Further research is needed in all patient groups to explore the ability of the 6MWT to measure significant and clinically important changes. Until then, changes measured with the 6MWT should be interpreted with caution. Future studies or consensus regarding modified test procedures in the pediatric population is recommended.

Physical activity, dietary habits and overall health in overweight and obese children and youth with intellectual disability or autism

In children and youth with disability, the risk of obesity is higher and is associated with lower levels of physical activity, inappropriate eating behaviors, and chronic health conditions. We determined the effectiveness of a program in managing weight, through changes in physical activity and nutrition behaviors in overweight and obese New Zealand children and youth with intellectual disability or autism. Twenty-two children and youth 14±4 y (mean±SD) and their families participated in a 10-week school-based program. The program consisted of 18 sessions focusing on physical activity and nutrition. Changes were measured immediately after completion of the program (post 1) and at 24 weeks (follow up). Fitness was assessed with the six-minute walk-test (6MWT) and body fatness via waist circumference and BMI. Physical activity and nutrition changes were measured by means of proxy reporting and interviews with parents. Individual interviews were conducted with school teachers and program leaders at 24 weeks to gain feedback regarding the program. Most quantitative outcomes were either unclear or trivial. The only possible change was observed in the six-minute walk-test where 24 weeks post program where participants walked 51 m further. There was however, a substantial reduction in the consumption of confectionery and chocolate at the two measurement points. Parents commented that during the program there were less hospital visits and absences from school related to illness. The program assisted in the development of a supportive community network and participants' abilities to partake in family and community activities. This the first study to report on the results of a physical activity and nutrition program targeted in children and youth with intellectual disability and autism. The results of this study may support and inform future developments of an integrated weight management and prevention program to enhance the health and well being in children and youth with disabilities.

Teste de caminhada de seis minutos em pediatria: relação entre desempenho e parâmetros antropométricos

INTRODUÇÃO: Diferenças antropométricas podem influenciar o desempenho no teste de caminhada de seis minutos (TC6). OBJETIVO: Analisar publicações referentes ao TC6 realizado em crianças e adolescentes e identificar a influência de parâmetros antropométricos no desempenho do teste. MATERAIS E MÉTODOS: Pesquisa nas bases de dados eletrônicas SciELO e MEDLINE, utilizando as palavras-chave: six-minute walk test, children, adolescents, anthropometric measures/variables, growth e exercise tolerance, na busca de estudos envolvendo TC6 em crianças e adolescentes, que apresentem correlação entre dados antropométricos e variáveis do teste. Foram identificados 45 trabalhos relacionados à busca e, após análise dos títulos, resumos e artigos na íntegra, foram incluídos 13 estudos compatíveis com o tema proposto. RESULTADOS: O material elencado aborda o TC6 e sua aplicação em diferentes situações: análise de reprodutibilidade, correlação com teste cardiopulmonar máximo, indicação em diferentes doenças, valores de referência em saudáveis, parâmetro de efeito de programas de prevenção/reabilitação. Muitos trabalhos relacionam a distância percorrida no TC6 com idade e sexo, bem como com variáveis antropométricas, evidenciando frequente correlação com altura, além de idade, peso e índice de massa corporal. Outros dados como comprimento e força de membros inferiores, porcentagem de massas gorda/magra e força muscular respiratória, relacionados às mudanças do período de desenvolvimento infanto-juvenil, também parecem influenciar no desempenho do teste. CONCLUSÃO: Estudos indicam forte influência entre variáveis antropométricas e distância percorrida no TC6 em crianças e adolescentes, e a necessidade de que se esclareça essa associação para que não haja comprometimento do desfecho de estudos e de terapêuticas.

Test-retest reliability and developmental evolution of the 6-min walk test in Caucasian boys aged 5-12 years

The 6-min walk test (6MWT) assesses functional capacity and has been used as outcome measure in therapeutic studies in childhood neuromuscular disorders. The objectives were to evaluate test-retest reliability of the 6MWT and to generate normative data for healthy boys aged 5-12 years. Ninety boys (mean age 8 years 10 months) were recruited over four age subcategories (5-6, 7-8, 9-10, 11-12 years). Mean 6MWT distance and velocity (±standard deviation) for the total group were 555.5±93 m and 92.6±16.6 m/min. The 6MWT distance increased significantly with age. Test-retest reliability (mean interval 12 days) was very high for the total group (ICC>0.95) and for all age subcategories (ICC>0.80) a moderately high reliability (ICC>0.75) was found from 3 min onwards for each age subcategory. There was a mean difference of 5.2 m between test and retest without systematic bias. The standard error of measurement and smallest detectable difference were 20.7 and 57.4 m, respectively. These findings demonstrate the reliability of the 6MWT in young children, underscore its evolution with age, and indicate that a shorter version of the test is also reliable.

Pedometer-assessed physical activity in children and young adults with CKD

BACKGROUND AND OBJECTIVES

Data on physical activity are limited in children with CKD. The objectives of this study were to measure the level and correlates of physical activity in children and young adults with CKD and to determine the association of physical activity with physical performance and physical functioning.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Physical activity was measured for 7 days using pedometers; physical performance was measured by the 6-minute walk distance (6MWD) and physical functioning with the PedsQL 4.0.

RESULTS

Study participants were 44 patients 7-20 years of age who had CKD stage 1-4 (n=12), had ESRD and were undergoing dialysis (n=7), or had undergone kidney transplantation (n=25). Participants were very sedentary; they walked 6218 (interquartile range, 3637, 9829) steps per day, considerably less than recommended. Physical activity did not differ among participants in the CKD stage 1-4, ESRD, and transplant groups. Females were less active than males (P<0.01), and physical activity was 44% lower among young adults (18-20 years) than younger participants (P<0.05). Physical activity was associated positively with maternal education and hemoglobin concentration and inversely with body mass index. Respective 6MWD in males and females was 2 and approximately 4 SDs below expected. Low levels of physical activity were associated with poor physical performance and physical functioning, after adjustment for age, sex, and body mass index.

CONCLUSIONS

In most participants with CKD, physical activity was considerably below recommended levels. Future studies are needed to determine whether increasing physical activity can improve physical performance and physical functioning.

Exercise for children with chronic kidney disease and end-stage renal disease

It is well known that adults suffering from chronic kidney disease (CKD) experience muscle wasting and excessive fatigue, which results in a reduced exercise capacity and muscle weakness compared to their healthy counterparts, but research suggests that this can be improved through exercise. There is very limited data available regarding exercise tolerance in children with CKD and even less on the effects of exercise training programs. However, the available evidence does suggest that like adults, children also suffer from poor exercise capacity and reduced muscle strength, although the reasons for these limitations remain unclear. Studies that have attempted to implement exercise training programs in pediatric CKD populations have experienced high dropout rates, suggesting that the approach used to implement such programs in children needs to be different from the approach used for adults. This review summarizes the current knowledge regarding exercise capacity and muscle strength in children with CKD, the methods used to perform these assessments, and the possible causes of physical limitations. The results of exercise training studies, and the potential reasons as to why training programs have proved relatively unsuccessful are also discussed.

Reproducibility, validity and predictors of six-minute walk test in overweight and obese adolescents with intellectual disability

OBJECTIVES

To assess the reproducibility and validity of the six-minute walk test (6MWT) and predictors of the six-minute walk distance (6MWD) in adolescents with overweight or obesity and intellectual disability (ID).

STUDY DESIGN

Sixty-one adolescents with overweight or obesity and mild-to-moderate ID (intelligent quotient [IQ] 40-70; age 14-22 years) participated in this study. To test reproducibility, 39 of the participants performed the 6MWT twice with an interval of 1 week. To test validity (n = 39), peak oxygen uptake (peak VO(2)) was measured on a bicycle ergometer. For the predictor study (n = 61), weight, height, peak VO(2) and quadriceps strength were measured, and IQ and orthopedic conditions were collected from the participants' medical records.

RESULTS

There was no significant difference between the means of the two 6MWTs (571.3 vs. 576.5 m; p = 0.452). The intraclass correlation coefficient was 0.82, indicating good reliability. The smallest real difference was 82.6 m. 6MWD correlated significantly with relative peak VO(2) (β = 0.69) indicating validity. Relative peak VO(2), height, IQ, body mass index (BMI) and quadriceps strength are predictors of the 6MWD in this population.

CONCLUSION

6MWT is a reliable and valid test in adolescents with overweight or obesity and ID. Low IQ, overweight/obesity and low physical fitness contribute to the outcome of the 6MWT.

Reference values on the 6-minute walk test for children living in the United States

PURPOSE

: The purpose of this study was to investigate reference values for the 6-minute walk test (6MWT) and the relationship between 6-minute walk distance (6MWD) and age, sex, and anthropometric variables in children who are healthy, aged 7 to 11 years and living in the United States.

METHODS

: The sample included 100 children, 57 female, 43 male, mean age 9.66 ± 1.08 years. Measures included height, weight, body mass index, leg length, and 6MWD.

RESULTS

: Mean 6MWD was 518.50 ± 73.56 m. Values were lower than those reported for children living in other countries with the exception of England. There were no significant associations between the 6MWD and other variables with the exception of body mass index in males.

CONCLUSION

: Our findings suggest 6MWT values for children living in other countries may not be directly applicable to children living in the United States.