Reference Equation For The Six-minute Walk Distance Of Chengdu Healthy Adults,Aged 20-29 Years

Objective: This study was undertaken to determine the 6MWD(Six-minute walk distance)in a sample of healthy young Adults in Chengdu,and to create a reference equation which could be used as a control group for the 6MWT(Six-minute walk test)used in patients,and a baseline for studying the clinical value of 6MWT further in the future.Methods: There were 390 healthy subjects aged 20-29 years performed two walking tests using a standardized protocol from October 1st to November 30 th.6MWD was defined as the greatest distance achieved from the two tests in the same day.The effect of anthropometrics on the 6MWD,the vital signs before and after the test and the subjects' feelings were also investigated.Using excel to input all the data and SPSS 22.0 software to perform t-test,?2 test,Pearson correlation analysis and multiple linear regression for significant test set of the first 300 subjects' data.Then using the reference equation to calculate predicted 6MWD of the rest subjects,and using t-test to evaluate validity of the reference equation.Using t-test for significant test between the 6MWD measured in our subjects and predicted 6MWD from the published reference equations.Results: All the 390 healthy subjects finished twice 6MWT,30 subjects' data was excluded.The average 6MWD was 649.17±27.93 m,with significantly longer distances by males(672.67±28.8 m)than females(637.24±18.28 m)(t=11.265,P<0.0001),and by subjects having physical training habit(660.41±31.6m)than the ones didn't have physical training habit(644.73±25.0m)(t=4.111,P<0.0001).Age,gender,height,weight,body mass index,the delta heart rate,the time spend on clamming down,SBp(Systolic blood pressure),DBp(diastolic blood pressure),mean arterial pressure,the physical training habit,heart rate after texting,SBp after texting,DBp after testing,pulse pressure after testing,calorie used were significantly positive correlated with 6MWD(P<0.05)while resting heart rate was significantly negative correlation with it(P<0.0001)in univariate analysis.The multiple regression by using 300 subjects' data showed gender(G),height(H),weight(W),body mass index(B),the delta heart rate(?HR),time spend on clamming down(T),physical training habit(E)were predictors of 6MWD and the reference equation for the Six-Minute Walk Distance of Chengdu healthy adults,aged 20-29 years was 6MWD=213.876+8.006G+2.403H-0.511W+1.818B+14.607E+0.338×?HR +0.056 T.The predicted 6MWD which was calculated by the reference equation of rest 60 subjects was 635.38±16.53 m,which was no significant difference with the real 6MWD they had walked(629.19±24.18m).Conclusion: 1.Reference equation for the 6MWD of 20-29 years old Chengdu healthy adults is 6MWD=213.876+8.006G+2.403H-0.511W+1.818B+14.607E+0.338 × ? HR +0.056 T,2.The reference equation we had can prognosticate 6MWD of Chengdu healthy adults,aged 20-29 years,3.The physical training habit was the most significant predictor of 6MWD.