Influence of diaphragm thickening fraction on exercise tolerance and dyspnea in patients with chronic obstructive pulmonary diseases
ZHANG Li-juan
WANG Fei-fei
MA Shao-lin
ZHU Xiao-ping
Abstract：Objective To evaluate change of diaphragm thickness in COPD patients,and to assess its influence on exercise tolerance and dyspnea in COPD.Methods Fifty subjects with COPD and 30 age-matched control subjects were included in the present study.All subjects were performed with the pulmonary function examination and ultrasound measurement of diaphragm thickness at FRC and TLC.The diaphragm thickening fraction was calculated by diaphragm thickness from FRC to TLC.The correlation of diaphragm thickness and thickening fraction with pulmonary function and exercise capacity was assessed.Result The COPD patients presented with lower diaphragm thickness at TLC (TD) and thickening change fraction(TF) compared with the control subjects (TD 0.38±0.10 vs.0.49±0.09;TF 1.02±0.45 vs.1.41±0.47,respectively,P＜0.05).The diaphragm thickening fraction presented a linear positive correlation with 6MWT (r=0.591,P＜0.01) and negative with dyspnea (r=--0.472,P＜0.01).Additionally,COPD patients were divided into two subgroups based on the degree of diaphragm thickening fraction:G1(≤ 1.458),G2(＞ 1.458).The G1 subjects presented poorer 6MWT and greater dyspnea when compared with the G2 patients (6MWT 371.95±95.73 vs.512.00±108.61;dyspnea 2.63±1.08 vs.1.70±0.82,P＜0.05).The G1 also presented lower airway obstruction (FEV1 47.41±16.70 vs.69.96±16.82,P＜0.05) and maximal voluntary ventilation (MVV 46.32±17.97 vs.62.60±22.13,P＜0.05) than the G2.Conclusion The reduction of diaphragm thickness and thickening fraction contributes to the exercise tolerance and dyspnea in COPD.
Keywords：ultrasoundchronic obstructive pulmonary diseasesdiaphragmexercise tolerancedyspnea
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：4( 552-554,575 )