Two-minute walk test: Reference equations for healthy adults in China.
ABSTRACT: BACKGROUND AND OBJECTIVE:Although the six-minute walk test (6MWT) is widely used as a measure of exercise capacity, it may not be applicable in some settings and populations. This issue has led to increased use of the two-minute walk test (2MWT) to assess exercise capacity. The main objective of this study is to establish reference equations for the two-minute walk distance (2MWD) in healthy Chinese adults aged 18-85 years. METHODS:A total of 973 volunteers took part in the study. We obtained verbal consent from all participants before the test, and the study design was approved by the ethics committees of Wenzhou People's Hospital. The participants performed two 2MWTs using a standardized protocol, and the longer distance was used for further analysis. Stepwise multiple regression analysis was performed using age, height and weight as independent variables and was used to establish the reference equations for the 2MWD in the male and female groups. RESULTS:The mean walking distance for all participants was 199.1±25.81 m. Age and height were identified as independent factors that influenced the 2MWD, and they explained 35% and 34% of the variance in distance for the male and female groups, respectively. CONCLUSION:This study resulted in determination of reference equations for predicting the 2MWD in healthy Chinese adults. These 2MWD standards will provide useful references for medical care in some settings and populations.
Project description:The two-minute walk test (2MWT) is less well validated than the well-known six-minute walk test (6MWT) as a field walking test in patients with chronic obstructive pulmonary disease (COPD). The primary objective of this study was to compare the accuracy of the 2MWT to the 6MWT in detecting exercise-induced oxygen desaturation in patients with severe COPD. Twenty-six patients with COPD (age: 61 ± 10 years, forced expired volume in one second: 37 ± 10%) that were normoxemic at rest performed a 2MWT and a 6MWT under normal ambient conditions on two consecutive days in random order. Oxygen saturation, total walking distance, heart rate, breathing frequency, dyspnea, and leg fatigue were evaluated. Average walking distances were 150 m (95% confidence interval (95% CI): 134-165 m) and 397 m (95% CI: 347-447 m) for the 2MWT and 6MWT, respectively (r = 0.80, p < 0.0001). The difference in minimum oxygen saturation during the 2MWT (83%, 95% CI: 81-86%) and 6MWT (mean 82%, 95% CI: 80-84%) was not statistically different and the data strongly correlated between the groups (r = 0.81, p < 0.0001). Other measurements from the 6MWT, including heart rate, breathing rate, and levels of perceived exertion were also comparable in 2MWT. The 2MWT showed comparable validity in detecting exercise-induced oxygen desaturation in patients with severe COPD compared to the 6MWT.
Project description:The six-minute walk test (6MWT) is a safe, simple, inexpensive tool for evaluating the functional exercise capacity of patients with chronic respiratory disease. However, there is a lack of standard reference equations for the six-minute walk distance (6MWD) in the healthy Chinese population aged 18-59 years.The purposes of the present study were as follows: 1) to measure the anthropometric data and walking distance of a sample of healthy Chinese Han people aged 18-59 years; 2) to construct reference equations for the 6MWD; 3) to compare the measured 6MWD with previously published equations.The anthropometric data, demographic information, lung function, and walking distance of Chinese adults aged 18-59 years were prospectively measured using a standardized protocol. We obtained verbal consent from all the subjects before the test, and the study design was approved by the ethics committee of Wenzhou People's Hospital. The 6MWT was performed twice, and the longer distance was used for further analysis.A total of 643 subjects (319 females and 324 males) completed the 6MWT, and average walking distance was 601.6±55.51 m. The walking distance was compared between females and males (578±49.85 m vs. 623±52.53 m; p < 0.0001) and between physically active subjects and sedentary subjects (609.3±56.17 m vs. 592±53.23 m; p < 0.0001). Pearson's correlation indicated that the 6MWD was significantly correlated with various demographic and the 6MWT variables, such as age, height, weight, body mass index (BMI), heart rate after the test and the difference in the heart rate before and after the test. Stepwise multiple regression analysis showed that age and height were independent predictors associated with the 6MWD. The reference equations from white, Canadian and Chilean populations tended to overestimate the walking distance in our subjects, while Brazilian and Arabian equations tended to underestimate the walking distance. There was no significant difference in the walking distance between Korean reference equations and the results of the current study.In summary, age and height were the most significant predictors of the 6MWD, and regression equations could explain approximately 34% and 28% of the distance variance in the female and male groups, respectively.
Project description:BACKGROUND:The six-minute walking test (6MWT) is a tool that plays a key role in evaluating the functional exercise capacity, prognosis and evaluation of treatment response of patients with various cardiopulmonary diseases. However, standard reference equations are currently unavailable for the six-minute walking distance (6MWD) for people aged 60-85?years in China. The purpose of this study was to 1) measure the 6MWD of healthy Chinese people aged 60-85?years, 2) establish reference equations for predicting the 6MWD, and 3) compare our reference equations with equations reported in previously published studies. METHOD:We obtained informed consent from each participant prior to the test, and the research design was approved by the Ethics Committee of Wenzhou People's Hospital. The demographic and anthropometric data and the 6MWD of healthy Chinese subjects aged 60-85?years old were measured using a standardized protocol. Every subject completed two 6MWTs, and the longest 6MWD further analyzed. RESULTS:Two hundred sixty-six subjects (128 males and 138 females) completed the 6MWT, and the mean walking distance was 518?±?72?m. Males achieved a longer walking distance than females (518?±?72?m vs. 487?±?70?m; p <?0.0001), and active subjects achieved a longer walking distance than nonactive subjects (512?±?76?m vs. 485?±?63?m; p <?0.0001). According to the univariate analysis, the 6MWD was significantly associated with age, height, body mass index (BMI), heart rate and blood pressure after exercise and changes in heart rate before and after exercise. The stepwise multivariate regression analysis identified age, height and BMI as independent predictors of the 6MWD. The reference equations for Caucasians and South Americans tended to overestimate the 6MWD of our subjects, while the equations for Asian and African populations tended to underestimate the 6MWD. CONCLUSIONS:This study is the first to describe the 6MWD of healthy Chinese people aged 60-85?years, and reference prediction equations were proposed. These findings will help to improve the evaluation of Chinese patients with diseases that affect exercise capacity.
Project description:<h4>Background</h4>Randomized trials of people with peripheral artery disease (PAD) and intermittent claudication have traditionally used maximal treadmill walking distance as the primary outcome, but the 6-minute walk test is increasingly used as a primary outcome in randomized trials of PAD. This study compared relative changes in maximal treadmill walking distance versus 6-minute walk distance in response to a therapeutic intervention or control in randomized trials of participants with PAD.<h4>Methods</h4>Data from four randomized trials of therapeutic interventions in participants with PAD that measured both 6-minute walk and treadmill walking performance at baseline and the 6-month follow-up were combined. Two trials studied supervised treadmill exercise, one studied home-based walking exercise, and one studied resveratrol.<h4>Results</h4>Of 467 participants (mean age, 69.8; standard deviation, 9.7), the mean ankle-brachial index was 0.66 (standard deviation, 0.17). At the 6-month follow-up, participants with PAD randomized to control or placebo significantly declined in 6-minute walk distance (-10.2 m; 95% confidence interval, -18.2 to -2.2; P = .013), but improved maximal treadmill walking distance (+25.7 m; 95% CI, +6.0 to +45.3 m; P = .010; difference between change in 6-minute walk versus maximal treadmill walking distance: -37.3 m; 95% CI, -56.4 to -18.2; P < .001). Home-based exercise improved the 6-minute walk distance by 43.2 m (95% CI, +28.4 to +57.9), and supervised treadmill exercise improved the 6-minute walk distance by 25.0 m (95% CI, +14.7 to +35.2; mean difference, +18.2 m favoring home-based exercise [95% CI, +0.2 to +36.2 m; P = .048]). Among all participants, the presence (vs absence) of treadmill exercise training was associated with a 141.3-m greater improvement in maximal treadmill walking distance compared to 6-minute walk distance (95% CI, 88.2-194.4; P < .001), suggesting a benefit from treadmill training on the treadmill outcome.<h4>Conclusions</h4>Maximal treadmill walking distance and the 6-minute walk distance are not interchangeable outcomes in participants with PAD. Participants with PAD randomized to control groups improved treadmill walking distance but simultaneously meaningfully declined in 6-minute walk distance. Supervised treadmill exercise training amplified improvement in treadmill walking distance because of a training to the outcome measure phenomenon.
Project description:Background It is currently unknown whether 6 months of supervised treadmill exercise has a durable benefit on 6-minute walk performance, even after exercise is completed, in people with peripheral artery disease. Methods and Results A total of 156 participants with peripheral artery disease were randomized to 1 of 3 groups: supervised treadmill exercise, supervised resistance training, or attention control. Participants received supervised sessions during months 1 to 6 and telephone contact during months 6 to 12. Primary outcomes were change in 6-minute walk distance and short physical performance battery at 6-month follow-up and have been reported previously. Secondary outcomes were change in 6-minute walk and short physical performance battery at 12-month follow-up and are reported here. A group of 134 participants (86%) completed the 12-month follow-up. At 6-month follow-up, compared with control, 6-minute walk distance improved in the treadmill exercise group (+36.1 m, 95% CI =13.9-58.3, P=0.001). Between 6- and 12-month follow-up, 6-minute walk distance significantly declined (-28.6 m, 95% CI=-52.6 to -4.5, P=0.020) and physical activity declined -272 activity units (95% CI =-546 to +2, P=0.052) in the treadmill exercise group compared with controls. At 12-month follow-up, 6 months after completing supervised treadmill exercise, change in 6-minute walk distance was not different between the treadmill exercise and control groups (+7.5, 95% CI =-17.5 to +32.6, P=0.56). There were no differences in short physical performance battery change between either exercise group and control at 6-month or 12-month follow-up. Conclusions A 6-month supervised treadmill exercise intervention that improved 6-minute walk distance at 6-month follow-up did not have persistent benefit at 12-month follow-up. These results do not support a durable benefit of supervised treadmill exercise in peripheral artery disease. Clinical Trial Registration URL : https://www.clinicaltrials.gov . Identifier: NCT 00106327.
Project description:Background The effects of race on response to medical therapy in people with peripheral artery disease ( PAD ) are unknown. Methods and Results In the PROPEL (Progenitor Cell Release Plus Exercise to Improve Functional Performance in PAD) Trial, PAD participants were randomized to 1 of 4 groups for 6 months: supervised treadmill exercise+granulocyte-macrophage colony-stimulating factor ( GM - CSF ) (Group 1), exercise+placebo (Group 2), attention control+ GM - CSF (Group 3), or attention control+placebo (Group 4). Change in 6-minute walk distance was measured at 12- and 26-week follow-up. In these exploratory analyses, groups receiving GM - CSF (Groups 1 and 3), placebo (Groups 2 and 4), exercise (Groups 1 and 2), and attention control (Groups 2 and 4) were combined, maximizing statistical power for studying the effects of race on response to interventions. Of 210 PAD participants, 141 (67%) were black and 64 (30%) were white. Among whites, GM - CSF improved 6-minute walk distance by +22.0 m (95% CI : -4.5, +48.5, P=0.103) at 12 weeks and +44.4 m (95% CI : +6.9, +82.0, P=0.020) at 26 weeks, compared with placebo. Among black participants, there was no effect of GM - CSF on 6-minute walk distance at 12-week ( P=0.26) or 26-week (-5.0 m [-27.5, +17.5, P=0.66]) follow-up, compared with placebo. There was an interaction of race on the effect of GM - CSF on 6-minute walk change at 26-week follow-up ( P=0.018). Exercise improved 6-minute walk distance in black ( P=0.006) and white ( P=0.034) participants without interaction. Conclusions GM - CSF improved 6-minute walk distance in whites with PAD but had no effect in black participants. Further study is needed to confirm racial differences in GM - CSF efficacy in PAD . Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 01408901.
Project description:Background Physical rehabilitation services are an important component of treatment for persons with multiple sclerosis (PwMS) to improve and maintain physical mobility. However, PwMS often have significant barriers to outpatient physical therapy (PT) services including mobility deficits and lack of transportation. The integration of exercise gaming (exergaming) and telehealth into clinical PT practices may overcome these barriers. The overarching purpose of this pilot study was to evaluate the acceptability and effects of an individualized telePT intervention using exergaming. Methods Ten individuals with multiple sclerosis (MS) completed a 12-week exergaming (Jintronix®) telerehabilitation intervention. In order to measure the acceptability of the telerehabilitation intervention, adherence was measured through the tablet-based rehabilitation software and each participant completed a satisfaction questionnaire. Clinical outcome measures were assessed at baseline and post-intervention. To evaluate the efficacy of this intervention, the following measures of physical function and fatigue were included; the Short Physical Performance Battery (SPPB), 25-Foot Walk (25FW), Modified Fatigue Impact Scale (MFIS), Multiple Sclerosis Walking Scale-12 (MSWS), and the 2-Minute Walk Test (2MWT). Clinical outcomes were analyzed using the Sign test and Wilcoxon signed rank test. All other data were evaluated using descriptive statistics. Results After the intervention, participants demonstrated significant improvements in ambulation speed during the 25FW (p?= 0.04) and ambulation distance during the 2MWT (p?=?0.002). Statistically significant increases of SPPB total score (p?=?.04) and sub-scores were also found. Participants did not demonstrate significant changes in the MFIS (p?=?0.31) or MSWS-12 (p?=?0.06) after the intervention. Participants had a 58.3% adherence rate during the intervention and performed their exercise program an average of 2.5 times per week. All participants reported that they were either ‘satisfied or ‘very satisfied’ with their telerehabilitation experience, would use telerehabilitation again, and would recommend telerehabilitation to others. Conclusion This individualized telerehabilitation intervention which integrates exergaming and clinical video teleconferencing is acceptable to patients and may offer a viable alternative to traditional PT for PwMS. Trial registration NCT03655431, retrospectively registered on August 31st, 2018.
Project description:Little is known about the physiologic determinants of 6-minute walk distance in idiopathic pulmonary fibrosis. We investigated the demographic, pulmonary function, echocardiographic, and hemodynamic determinants of 6-minute walk distance in patients with idiopathic pulmonary fibrosis evaluated for lung transplantation. We performed a cross-sectional analysis of 130 patients with idiopathic pulmonary fibrosis who completed a lung transplantation evaluation at the Hospital of the University of Pennsylvania between 2005 and 2010. Multivariable linear regression analysis was used to generate an explanatory model for 6-minute walk distance. After adjustment for age, sex, race, height, and weight, the presence of right ventricular dilation was associated with a decrease of 50.9 m (95% confidence interval [CI], 8.4-93.3) in 6-minute walk distance ([Formula: see text]). For each 200-mL reduction in forced vital capacity, the walk distance decreased by 15.0 m (95% CI, 9.0-21.1; [Formula: see text]). For every increase of 1 Wood unit in pulmonary vascular resistance, the walk distance decreased by 17.3 m (95% CI, 5.1-29.5; [Formula: see text]). Six-minute walk distance in idiopathic pulmonary fibrosis depends in part on circulatory impairment and the degree of restrictive lung disease. Future trials that target right ventricular morphology, pulmonary vascular resistance, and forced vital capacity may potentially improve exercise capacity in patients with idiopathic pulmonary fibrosis.
Project description:Benefits of granulocyte-macrophage colony-stimulating factor (GM-CSF) for improving walking ability in people with lower extremity peripheral artery disease (PAD) are unclear. Walking exercise may augment the effects of GM-CSF in PAD, since exercise-induced ischemia enhances progenitor cell release and may promote progenitor cell homing to ischemic calf muscle.To determine whether GM-CSF combined with supervised treadmill exercise improves 6-minute walk distance, compared with exercise alone and compared with GM-CSF alone; to determine whether GM-CSF alone improves 6-minute walk more than placebo and whether exercise improves 6-minute walk more than an attention control intervention.Randomized clinical trial with 2?×?2 factorial design. Participants were identified from the Chicago metropolitan area and randomized between January 6, 2012, and December 22, 2016, to 1 of 4 groups: supervised exercise?+?GM-CSF (exercise?+?GM-CSF) (n?=?53), supervised exercise?+?placebo (exercise alone) (n?=?53), attention control??+?GM-CSF (GM-CSF alone) (n?=?53), attention control?+?placebo (n?=?51). The final follow-up visit was on August 15, 2017.Supervised exercise consisted of treadmill exercise 3 times weekly for 6 months. The attention control consisted of weekly educational lectures by clinicians for 6 months. GM-CSF (250 ?g/m2/d) or placebo were administered subcutaneously (double-blinded) 3 times/wk for the first 2 weeks of the intervention.The primary outcome was change in 6-minute walk distance at 12-week follow-up (minimum clinically important difference, 20 m). P values were adjusted based on the Hochberg step-up method.Of 827 persons evaluated, 210 participants with PAD were randomized (mean age, 67.0 [SD, 8.6] years; 141 [67%] black, 82 [39%] women). One hundred ninety-five (93%) completed 12-week follow-up. At 12-week follow-up, exercise?+?GM-CSF did not significantly improve 6-minute walk distance more than exercise alone (mean difference, -6.3 m [95% CI, -30.2 to +17.6]; P?=?.61) or more than GM-CSF alone (mean difference, +28.7 m [95% CI, +5.1 to +52.3]; Hochberg-adjusted P?=?.052). GM-CSF alone did not improve 6-minute walk more than attention control?+?placebo (mean difference, -1.4 m [95% CI, -25.2 to +22.4]; P?=?.91). Exercise alone improved 6-minute walk compared with attention control?+?placebo (mean difference, +33.6 m [95% CI, +9.4 to +57.7]; Hochberg-adjusted P?=?.02).Among patients with PAD, supervised treadmill exercise significantly improved 6-minute walk distance compared with attention control?+?placebo, whereas GM-CSF did not significantly improve walking performance, either when used alone or when combined with supervised treadmill exercise. These results confirm the benefits of exercise but do not support using GM-CSF to treat walking impairment in patients with PAD.clinicaltrials.gov Identifier: NCT01408901.
Project description:To evaluate the agreement between the measured peak oxygen uptake (VO2peak) and the VO2peak estimated by four prediction equations based on the six-minute walk test (6MWT) in chronic heart failure patients.Thirty-six chronic heart failure patients underwent cardiopulmonary exercise testing and the 6MWT to assess their VO2peak. Four previously published equations that include the variable six-minute walk distance were used to estimate the VO2peak: Cahalin, 1996a (1); Cahalin, 1996b (2); Ross, 2010 (3); and Adedoyin, 2010 (4). The agreement between the VO2peak in the cardiopulmonary exercise testing and the estimated values was assessed using the Bland-Altman method. A p-value of <0.05 was considered statistically significant.All estimated VO2peak values presented moderate correlation (ranging from 0.55 to 0.70; p<0.001) with measured VO2peak values. Equations 2, 3, and 4 underestimated the VO2peak by 30%, 15.2%, and 51.2%, respectively, showing significant differences from the actual VO2peak measured in the cardiopulmonary exercise testing (p<0.0001 for all), and the limits of agreement were elevated. The VO2peak estimated by equation 1 was similar to that measured by the cardiopulmonary exercise testing, and despite the agreement, bias increased as VO2peak increased.Only equation 1 showed estimated VO2peak similar to the measured VO2peak; however, a large limits of agreement range (∼3 METs) does not allow its use to estimate maximal VO2peak.