Incremental Shuttle Walk Test Distance Research Articles

703 SARCOPENIA OBESITY AND MYOSTEATOSIS ARE RISK FACTORS FOR COMPLICATIONS FOLLOWING RESECTION OF OESOPHAGOGASTRIC CANCERS

Abstract Oesophagogastric cancer resection carries a morbidity, as high as 60%. Better patient selection, not only with regards to clinical stage but also with fitness reduces morbidity and improves outcome. Assessment of sarcopenia (SMI) and incremental shuttle walk test (ISWT) are two such tools to evaluate patients’ fitness. We investigate the influence of these two tools in predicting post-operative outcomes following Oesophagogastric resection. Methods All patients who underwent Oesophagogastric cancer resection between 2017–2019 and consented to participate in ISWT were included and outcomes evaluated retrospectively. Patient demographics, comorbidity profile and distance walked in ISWT were collected from the hospital cancer database. SMI was calculated on the pre-operative staging CT at the level of L3. Outcomes assessed included overall complications, major complications (Clavien-Dindo III-V) and 30-day mortality. Results Sixty-seven patients (median age = 67) met the inclusion criteria with majority receiving neoadjuvant chemotherapy (79%). Overall complication rate was 69% including 34% major complications. There was no difference in overall and major complication between patients with ISWT distance of >350 and < 350 m. Sarcopenia was diagnosed in 58% of the patients. Adjusted analyses showed female patients (OR: 9.31, CI95%: 1.49–94.15, p = 0.030), myosteatosis (OR: 7.52, CI95%: 1.64–48.62, p = 0.017), and sarcopenic obesity (OR: 6.16, CI95%: 3.28–36.59, p = 0.021) to be independent predictors of overall complications. Correlation plot shows no interaction between SMI and ISWT scores. Conclusion: The study shows that ISWT does not predict post-operative mortality and morbidity following Oesophagogastric cancer resection. Sarcopenia is associated with higher overall complication rates. SMI and ISWT score do not correlate in predicting post-operative outcomes. We recommend that assessment of sarcopenia to be used routinely as a pre-operative assessment tool for prediction of outcomes in patients undergoing Oesophagogastric cancer resection.

Pulmonary Rehabilitation in Noncystic Fibrosis Bronchiectasis

Background: Current guidelines for the treatment of noncystic fibrosis bronchiectasis (NCFB) recommend pulmonary rehabilitation (PR), but to date, there are few studies that have proven its effectiveness. Objective: The main objective of this study was to examine the effect of PR on pulmonary function tests and exercise capacity. Method: The aim of this study was to systematically review the effects of PR in NCFB on (1) forced expiratory volume in the first second (FEV₁) and (2) exercise capacity evaluated by the 6-min walk test (6MWT) and the incremental shuttle walk test (ISWT). This meta-analysis was undertaken according to PRISMA recommendations. Results: This pair-wise meta-analysis included data obtained from studies that enrolled 529 NCFB patients. The FEV₁ assessment after PR between the active and control group did not show any significant increase (FEV₁ difference 0.084 mL; CI: −0.064, +0.233; p = 0.264), and there was an increasing trend (188 mL; CI: −0 to 0.009, +0.384) at the limits of statistical significance (p = 0.061). Walked distance showed a significant increase in the PR group compared to the control group (ISWT distance difference 070.0 m; CI: 55.2, 84.8; p < 0.001), and this finding was confirmed before and after PR both by the ISWT (68.85 m greater than baseline; CI: 40.52, 97.18; p < 0.001) and by the 6MWT (37.7 m greater than baseline; CI: 20.22, 55.25; p < 0.001). Conclusions: PR improves exercise tolerance in NCFB patients, but it has a modest impact on respiratory function.

Health-related quality of life associates with clinical parameters in patients with NTM pulmonary disease.

BACKGROUND: Previous studies have shown a reduction in health-related quality of life (HRQoL) in patients with non-tuberculous mycobacterial pulmonary disease (NTM-PD). However, the causes of this decline and the factors that contribute to it are unknown. This study was conducted to analyse the association between the St George´s Respiratory Questionnaire (SGRQ) and clinical parameters, including age, disease duration, body composition, pulmonary function, chest X-ray findings, blood data and physical function.METHODS: We performed a single-centre, cross-sectional, retrospective study of 101 patients with NTM-PD from December 2016 to October 2019. The relationship between the SGRQ scores and clinical parameters was evaluated.RESULTS: The median patient age was 67.0 years. Pulmonary function, radiological score, albumin levels, C-reactive protein levels and incremental shuttle walk test distance (ISWD) were significantly correlated with the total and component scores on the SGRQ. Multiple regression analysis showed that the SGRQ score was significantly associated with radiological score, pulmonary function and ISWD.CONCLUSION: This study was the first to assess the effect of clinical parameters on the SGRQ in patients with NTM-PD. HRQoL as determined using the SGRQ was associated with the radiological score, pulmonary function and ISWD in patients with NTM-PD.

Home-based pulmonary rehabilitation in people with bronchiectasis: a randomised controlled trial.

AimTo investigate the short- and long-term effects of home-based pulmonary rehabilitation (HBPR) on functional capacity, quality of life, peripheral muscle strength, dyspnoea and daily physical activity in people with bronchiectasis.MethodsRandomised controlled trial with 63 participants with bronchiectasis. The HBPR group performed three sessions per week for 8 weeks (aerobic exercise: step training for 20 min; resistance training: exercises for quadriceps, hamstrings, deltoids and biceps brachii using elastic bands). The control group received a recommendation to walk at moderate intensity, three times per week. A weekly phone call was conducted for all participants, and the HBPR group received a home visit every 15 days. The primary outcome was distance in the incremental shuttle walk test (ISWT). Secondary outcomes were time in the endurance shuttle walk test (ESWT), number of steps in the incremental step test, quality of life, quadriceps muscle strength and daily physical activity. Measures were taken before and after intervention and 6 months later.ResultsAfter the intervention, the HBPR group had increased ISWT distance compared with the control group with between-group difference 87.9 m (95% CI 32.4–143.5 m). In addition, between-group differences were found in the ESWT, incremental step test, quality of life and quadriceps muscle strength, favouring the HBPR group. After 6 months, no differences were observed between the groups.ConclusionHBPR is an effective alternative offering of pulmonary rehabilitation for people with bronchiectasis. However, the programme was not effective in maintaining the benefits after 6 months of follow-up.

A double-blind randomised controlled trial of protein supplementation to enhance exercise capacity in COPD during pulmonary rehabilitation: a pilot study.

BackgroundPulmonary rehabilitation is a cost-effective management strategy in chronic obstructive pulmonary disease (COPD) which improves exercise performance and health-related quality of life. Nutritional supplementation may counter malnutrition and enhance pulmonary rehabilitation outcomes but rigorous evidence is absent. We aimed to investigate the effect of high-protein supplementation (Fortisip Compact Protein (FCP)) during pulmonary rehabilitation on exercise capacity.MethodsThis was a double-blind randomised controlled trial comparing FCP (intervention) with PreOp (a carbohydrate control supplement) in COPD patients participating in a pulmonary rehabilitation programme. Participants consumed the supplement twice a day during pulmonary rehabilitation and attended twice-weekly pulmonary rehabilitation sessions, with pre- and post-pulmonary rehabilitation measurements, including the incremental shuttle walk test (ISWT) distance at 6 weeks as the primary outcome. Participants’ experience using supplements was assessed.Results68 patients were recruited (intervention n=36 and control n=32). The trial was stopped early due to the COVID-19 pandemic. Although statistical significance was not reached, there was the suggestion of a clinically meaningful difference in the ISWT distance at 6 weeks favouring the intervention group (intervention 342±149 m (n=22) versus control 305±148 m (n=22); p=0.1). Individuals who achieved an improvement in the ISWT had a larger mid-thigh circumference at baseline (responders 62±4 cm versus nonresponders 55±6 cm; p=0.006). 79% of the patients were satisfied with the taste and 43% would continue taking the FCP.ConclusionsAlthough the data did not demonstrate a statistically significant difference in the ISWT, high-protein supplementation in COPD during pulmonary rehabilitation may result in a clinically meaningful improvement in exercise capacity and was acceptable to patients. Large, adequately powered studies are justified.

The cardiovascular determinants of physical function in patients with end-stage kidney disease on haemodialysis

Patients with end-stage kidney disease (ESKD) are often sedentary and decreased functional capacity associates with mortality. The relationship between cardiovascular disease (CVD) and physical function has not been fully explored. Understanding the relationships between prognostically relevant measures of CVD and physical function may offer insight into how exercise interventions might target specific elements of CVD. 130 patients on haemodialysis (mean age 57 ± 15 years, 73% male, dialysis vintage 1.3 years (0.5, 3.4), recruited to the CYCLE-HD trial (ISRCTN11299707), underwent cardiovascular phenotyping with cardiac MRI (left ventricular (LV) structure and function, pulse wave velocity (PWV) and native T1 mapping) and cardiac biomarker assessment. Participants completed the incremental shuttle walk test (ISWT) and sit-to-stand 60 (STS60) as field-tests of physical function. Linear regression models identified CV determinants of physical function measures, adjusted for age, gender, BMI, diabetes, ethnicity and systolic blood pressure. Troponin I, PWV and global native T1 were univariate determinants of ISWT and STS60 performance. NT pro-BNP was a univariate determinant of ISWT performance. In multivariate models, NT pro-BNP and global native T1 were independent determinants of ISWT and STS60 performance. LV ejection fraction was an independent determinant of ISWT distance. However, age and diabetes had the strongest relationships with physical function. In conclusion, NT pro-BNP, global native T1 and LV ejection fraction were independent CV determinants of physical function. However, age and diabetes had the greatest independent influence. Targeting diabetic care may ameliorate deconditioning in these patients and a multimorbidity approach should be considered when developing exercise interventions.

Oral nitrate supplementation to enhance pulmonary rehabilitation in COPD: ON-EPIC a multicentre, double-blind, placebo-controlled, randomised parallel group study

RationaleDietary nitrate supplementation has been proposed as a strategy to improve exercise performance, both in healthy individuals and in people with COPD. We aimed to assess whether it could enhance...

Visuomotor reaction time and dynamic balance in children with cystic fibrosis and non-cystic fibrosis bronchiectasis: A case-control study.

Extrapulmonary involvement such as balance and reaction time is unclear in cystic fibrosis (CF) patients. The aim of this study was to evaluate visuomotor reaction time (VMRT) and dynamic balance in children with CF and non-CF bronchiectasis compared to healthy children. Demographic and clinical characteristics were recorded. All children were evaluated with pulmonary function test (PFT) using a spirometer, incremental shuttle walk test (ISWT) for exercise capacity, Fitlight Trainer for VMRT, and functional reach test (FRT) for dynamic balance. Fourteen children with CF (10.71 ± 2.94 years, 7 females), 17 children with non-CF bronchiectasis (12.75 ± 2.81 years, 8 females), and 21 healthy children (11.36 ± 3.28 years, 11 females) were included. Children with CF had longer total VMRT (P = .027), poorer FRT performance (P = .001), and shorter ISWT distances (P = .03) compared to the children with non-CF bronchiectasis and controls. Although total VMRT was longest in the CF group, there was no significant difference in mean VMRT among the CF, non-CF bronchiectasis, and control groups (P > .05). Dynamic balance and VMRT show greater impairment in children with CF than in children with non-CF bronchiectasis compared to healthy controls. Our findings suggest that VMRT and dynamic balance should be taken into consideration for assessments and exercise programs in pulmonary rehabilitation.

Exercise Capacity and Activities of Daily Living are Related in Patients With Chronic Obstructive Pulmonary Disease

IntroductionThe knowledge of the relationship between exercise capacity and activities of daily living (ADLs) is important to minimize the negative outcomes in ADLs resulting from reduced exercise capacity in patients with chronic obstructive pulmonary disease (COPD). There is a limited study about the association between exercise capacity and ADLs in patients with COPD. This study aimed to investigate the relationship between maximal exercise capacity and ADLs in patients with GOLD stage II–III COPD. MethodsTwenty-seven clinically stable GOLD stage II–III COPD patients were included (mean age=58.59±9.63 years and mean FEV1=50.6±13.7%) in this cross-sectional study. Maximal and submaximal exercise capacity were evaluated using an incremental shuttle walk test (ISWT) and 6-min walk test (6MWT), respectively. Activities of daily living were assessed using Glittre-ADL test. ResultsThe ISWT distance was significantly correlated with Glittre-ADL test time (r=−0.517, p=0.006). There was also a negative correlation between 6MWT distance and Glittre-ADL test time (r=−0.506, p=0.007). ConclusionA moderate relationship was found between maximal exercise capacity and general activities of daily living performance. The reduction in exercise capacity increases the negative influences in ADLs and strengthens our beliefs that exercise interventions in pulmonary rehabilitation could influence activities of daily living positively.

DOES HABITUAL PHYSICAL ACTIVITY LEVEL INFLUENCE AEROBIC CAPACITY AND HEART RATE VARIABILITY IN POSTMENOPAUSAL WOMEN?

ABSTRACT The aim of this research was to verify whether habitual physical activity level (HPAL) influences aerobic capacity and parasympathetic activity at rest in postmenopausal women. Thirty postmenopausal women participated in the study (59.3 ± 5.3 years old; 1.58 ± 0.06 m; 64.5 ± 9.6 kg; 25.6 ± 3.1 body mass index; 27 ± 5%fat). The women were divided into two groups based on the median pedometer step count of HPAL (G1 = HPAL) and submitted to the incremental shuttle walking test (ISWT) and analysis of heart rate variability (HRV) at rest. Substantial differences were found between G1 and G2 for step count (p = 0.0001); effect size (ES) = 2.55), ISWT distance (p = 0.0002; ES = 2.24), root mean square of successive difference (RMSSD) (p = 0.0001; ES = 1.56), and high-frequency band (p = 0.0001; ES = 1.31). In conclusion, postmenopausal women with higher HPAL have greater aerobic capacity and parasympathetic modulation of HRV.

Evaluation of exercise capacity using two field tests in patients with metabolic syndrome

Purpose Field tests are popular for assessing exercise capacity because they are practical and have established validity. The objective of this study was to compare physiological responses and exercise performance of patients with metabolic syndrome in two field tests of exercise capacity. Material and Methods Forty-seven patients diagnosed with metabolic syndrome participated in this cross-sectional study. Exercise capacity was assessed using incremental shuttle walk test and six-minute walk test. Factors determining exercise capacity and agreement between the two tests were also investigated. Results Metabolic syndrome patients achieved a significantly greater percentage of predicted maximal heart rate, blood pressure, and longer distance in the incremental shuttle walk test than in the six-minute walk test (p < 0.001). Gender and body mass index explained 48.5% of the variance in six-minute walk test distance (R = 0.697, R 2 = 0.485, F (2-46) = 20.737, p < 0.001). Body mass index and fat-free mass explained 55% of the variance in incremental shuttle walk test distance (R = 0.746, R 2= 0.557, F (2-46) = 27.623, p < 0.001). Conclusions Despite the agreement in the percentages of predicted maximal heart rate during these two field tests, the incremental shuttle walk test may be a better assessment tool than the six-minute walk test because it elicits more pronounced and definitive physiological responses to exercise tolerance in patients with metabolic syndrome. IMPLICATIONS FOR REHABILITATION The incremental shuttle walk test can be used to evaluate exercise capacity in metabolic syndrome. The incremental shuttle walk test elicits greater physiological responses than the six-minute walk test. The incremental shuttle walk test may be preferable over the six-minute walk test in investigating exercise capacity. Both tests can guide and assist in the evaluation of this patient population in clinical practice. Body mass index affected distance in both exercise tests.

Exercise Capacity and Activities of Daily Living are Related in Patients With Chronic Obstructive Pulmonary Disease

IntroductionThe knowledge of the relationship between exercise capacity and activities of daily living (ADLs) is important to minimize the negative outcomes in ADLs resulting from reduced exercise capacity in patients with chronic obstructive pulmonary disease (COPD). There is a limited study about the association between exercise capacity and ADLs in patients with COPD. This study aimed to investigate the relationship between maximal exercise capacity and ADLs in patients with GOLD stage II–III COPD. MethodsTwenty-seven clinically stable GOLD stage II–III COPD patients were included (mean age=58.59±9.63 years and mean FEV1=50.6±13.7%) in this cross-sectional study. Maximal and submaximal exercise capacity were evaluated using an incremental shuttle walk test (ISWT) and 6-min walk test (6MWT), respectively. Activities of daily living were assessed using Glittre-ADL test. ResultsThe ISWT distance was significantly correlated with Glittre-ADL test time (r=−0.517, p=0.006). There was also a negative correlation between 6MWT distance and Glittre-ADL test time (r=−0.506, p=0.007). ConclusionA moderate relationship was found between maximal exercise capacity and general activities of daily living performance. The reduction in exercise capacity increases the negative influences in ADLs and strengthens our beliefs that exercise interventions in pulmonary rehabilitation could influence activities of daily living positively.

Fit 4 surgery, a bespoke app with biofeedback delivers rehabilitation at home before and after elective lung resection

BackgroundPulmonary rehabilitation programme for lung surgery patients can reduce the risk of post-operative complications but compliance to programmes can be limited by access to health care. We developed a home-based rehabilitation app and tested its feasibility in patients undergoing lung resection surgery.MethodsA cohort study was conducted over 18 months at a regional thoracic unit. The Fit 4 Surgery app included ten exercises. Patients were instructed to exercise for at least three minutes for each exercise. Data was transmitted back to the researchers remotely. Data was also collected from a contemporaneous group of surgery patients who attended local outpatient-based Chronic Obstructive Pulmonary Disease rehabilitation classes. Quality of Life and outcomes data in the app group were collected. Patients were also interviewed about their experience of the app.ResultsApp patients had a shorter wait before surgery compared to patients attending rehabilitation classes (24 vs 45 days) but managed four times as many sessions (2 vs 9), improving incremental shuttle walk test distance by 99 ± 83 (p < 0.05) metres before surgery. Five themes were gathered from the interviews.ConclusionAn app based programme of rehabilitation can be delivered in a timely fashion to lung surgery patients with demonstrable physiological benefits; this will need to be confirmed in further clinical trials.Clinical trial registration numberISRCTN00061628. Registered 27 May 2011.

The Efficacy of Outpatient Pulmonary Rehabilitation After Bilateral Lung Transplantation.

Pulmonary rehabilitation (PR) is advocated in the pre- and post-lung transplantation (LTx) periods. However, there is limited literature on the benefit of PR post-LTx. The aim of this study was to investigate the efficacy of an outpatient, multidisciplinary, comprehensive PR program in bilateral LTx recipients in the early period after LTx. Twenty-three LTx recipients were referred to the PR center. Change in incremental and endurance shuttle walk tests, hand and quadriceps strength, respiratory muscle strength (maximum inspiratory/expiratory pressure), dyspnea (Medical Research Council score), quality of life (St George's Respiratory Questionnaire, Chronic Respiratory Questionnaire), and psychological status (Hospital Anxiety Depression Scale) were compared pre- and post-PR. Seventeen of 23 (74%) recipients completed PR, comprising 15 male and 2 female patients whose median age was 51 yr. The initiation of the program was 75 ± 15 d after LTx. The incremental shuttle walk test distance was predicted as 23% before PR and it increased to 36% after PR (P < .001); the endurance shuttle walk test distance also increased (P < .01). Significant improvement was seen in upper and lower extremity strength, and St George's Respiratory Questionnaire and Chronic Respiratory Questionnaire scores and Hospital Anxiety Depression Scale scores reflected less anxiety and depressive symptoms. Furthermore, body mass and fat-free mass indices, maximum inspiratory pressure, and maximum expiratory pressure improved significantly. There was no significant change in forced expiratory volume in the first second of expiration, forced vital capacity, or Medical Research Council scores. This study demonstrated that patients who attended PR within 3 mo of bilateral LTx showed improvements in exercise capacity, respiratory muscle strength, quality of life, body composition, and psychological status.

Minimum important difference of the incremental shuttle walk test distance in patients with COPD

We aimed to describe the minimum important difference (MID) of the incremental shuttle walk test (ISWT) in patients with COPD using both distribution and anchor-based methods. Two cohorts were used...

Reference equation for the incremental shuttle walk test in Portuguese children and adolescents

BackgroundThe incremental shuttle walk test (ISWT) is one of the most widely used field tests to assess cardiorespiratory fitness in clinical and research settings. Reference equations to predict ISWT distance in different populations and age cohorts have been established. However, an equation for the Portuguese pediatric population is not available. This study aimed to develop a reference equation for predicting ISWT in Portuguese children and adolescents. MethodHealthy children and adolescents aged between 5 and 17 years old were recruited. Sociodemographic (sex, age), anthropometric (height, weight) and physical activity (Physical Activity Index) data were collected. Lung function was assessed through spirometry and quadriceps muscular strength through hand-held dynamometry. The ISWT was performed twice. A reference equation was established with a multiple linear regression. Results130 (60 male; 13.66±2.61y) participants with normal lung function (forced expiratory volume in one second 102.73±15.09% predicted), body mass index (BMI) (20.27±3.59kg/m2) and quadriceps muscular strength (19.75±6.84kgf), completed the assessment. 50.8% (n=66) of the participants were moderately active. Participants walked on average 1165.08±327.19m in the ISWT. Sex, age and BMI were independent contributors to the ISWT, explaining 54% of its variability (p<0.001). The derived reference equation was: ISWT=342.06+(283.07×sex)+(83.61×age)−(22.22×BMI), with female=0 and male=1. ConclusionSex, age and BMI were found to be contributors to the ISWT predictive equation for pediatric population, providing a simple reference to assess their cardiorespiratory fitness.

Validity of the Incremental Shuttle Walk Test to Assess Exercise Safety When Initiating Cardiac Rehabilitation in Low-Resource Settings.

To evaluate the validity of the Incremental Shuttle Walk Test (ISWT) for determining risk stratification in cardiac rehabilitation (CR). This is a cross-sectional study at a major CR center in a middle-income country. Clinically stable adult cardiac patients underwent an ISWT and an exercise test (ET), wore a pedometer for 7 d, and completed the Godin-Shepherd Leisure-Time Physical Activity Questionnaire. Metabolic equivalents of task (METs) achieved on the ISWT were calculated. One hundred fifteen patients were evaluated. The mean ± standard deviation distance on the ISWT was 372.70 ± 128.52 m and METs were 5.03 ± 0.62. The correlation of ISWT distance with ET METs (7.57 ± 2.57), steps/d (4556.71 ± 3280.88), and self-reported exercise (13.08 ± 15.19) was rs = 0.61 (P < .001), rs = 0.37 (P < .001), and rs = 0.20 (P = .031), respectively. Distance on the ISWT accurately predicted METs from the ET (area under the receiver operating characteristic curve = 0.774). The ability to walk ≥410 m on the ISWT predicted, with a specificity of 81.5% and a sensitivity of 65.6%, a functional capacity of ≥7 METs on ET. The ISWT is an alternative way to evaluate functional capacity in CR and can contribute to the process of identifying patients at low risk for a cardiac event during exercise at moderate intensity.

The incremental shuttle walk test predicts mortality in non-group 1 pulmonary hypertension: results from the ASPIRE Registry.

Pulmonary hypertension (PH) is classified into five groups based on disease etiology but there is only limited information on the prognostic value of exercise testing in non-group 1 PH. In group 1 PH, the incremental shuttle walking test (ISWT) distance has been shown to correlate with pulmonary hemodynamics and predict survival without a ceiling effect. This study assessed the ISWT in non-group 1 PH. Data were retrieved from the ASPIRE Registry (Assessing the Spectrum of Pulmonary hypertension Identified at a REferral centre) for consecutive patients diagnosed with PH. Patients were required to have been systematically assessed as group 2–5 PH and to have a baseline ISWT within three months of cardiac catheterization. Patients were stratified according to incremental shuttle walk test distance (ISWD) and ISWT distance percent predicted (ISWD%pred). A total of 479 patients with non-group 1 PH were identified. ISWD and ISWD%pred correlated significantly with symptoms and hemodynamic severity. ISWD and ISWD%pred predicted survival with no ceiling effect. The test was prognostic in groups 2, 3, and 4. ISWD and ISWD%pred and change in ISWD and ISWD%pred at one year were all significant predictors of outcome. In patients with non-group 1 PH the ISWT is a simple non-invasive test that is easy to perform, is predictive of survival at baseline and follow-up, reflects change, and can be used in the assessment of PH of any etiology.

FUNCTIONAL CAPACITY IN ADOLESCENT IDIOPATHIC SCOLIOSIS DURING THE POSTOPERATIVE PERIOD

ABSTRACT Introduction: Patients with Adolescent Idiopathic Scoliosis (AIS) show reduced exercise capacity during the Incremental Shuttle Walk Test (ISWT). However, we not know how patients behave in the late postoperative (LPO) period. Objective: The aim of this study was to evaluate the ISWT distance (ISWTD) and physiological responses during ISWT in AIS patients during the LPO period. Methods: We included 22 patients with AIS in the LPO period (SG) and 21 adolescents in the Control Group (CG). We assessed pulmonary function (FVC and FEV1). During ISWT, a gas analyzer was used to assess peak oxygen (VO2) and submaximal relations: Oxygen Uptake Efficiency Slope (OUES) and the breathing pattern (ΔVT/ΔlnVE). Results: Significantly lower values were observed in SG: VO2 (22 ± 5 vs. 27 ± 4), ISWTD (567 ± 94 vs.604 ± 86), FVC (2.70 ± 0.47 vs. 3.33 ± 0.52) and FEV1 (2.41 ± 0.46 vs. 2.84 ± 0.52). There were significant correlations between ISWTD and VO2/Kg (r = 0.80); between OUES and ΔVT/ΔlnVE (r = 0.65); and between the main thoracic curve with VO2/Kg (r= −0.61). Conclusion: AIS patients in the LPO period have significantly reduced exercise capacity associated with reduced lung function, residual spinal curve and cardiovascular deconditioning. Level of Evidence III; Prognostic Studies - Investigation of the effect of characteristic of a patient on the outcome of the disease.

Understanding the measurement properties of the incremental shuttle walk test in patients with severe asthma.

We investigated the repeatability and validity of the incremental shuttle walk test (ISWT) distance compared to peak oxygen uptake (VO2pk ) during maximal incremental cycle ergometer (ICE) and treadmill (ITM) tests in adults with severe asthma. Adults with severe asthma, Medical Research Council (MRC) dyspnoea ≥2, were recruited from specialists caring for patients with severe asthma. All participants performed three ISWT (familiarization and two subsequent tests on the same day), an ICE and an ITM in a randomized order, on separate days, to intolerance with expiratory gas analysis. A total of 50 patients (32 females, mean (SD), age: 54 (13) years, forced expiratory volume in 1 s (FEV1 ): 1.9 (0.8) L and body mass index (BMI): 32 (6) kg/m2 ) completed all five tests. The mean (SD) ISWT distance for each test was 400 (156), 418 (142) and 438 (157) m (P = 0.001), respectively. There was a strong correlation between the ISWT distance with VO2pk derived from ITM (r = 0.74, P < 0.001) and ICE (r = 0.75, P < 0.001). There was a small increase in the mean ISWT distance on sequential testing. In clinical practice, the coefficient of repeatability and heteroscedasticity need to be considered when assessing whether a true change has occurred within an individual patient. The ISWT has validity compared to VO2pk on both ICE and ITM, but they are not interchangeable.