Introduction:
The progression of Cystic fibrosis (CF) lung disease can be assessed by different clinical parameters such as spirometry, chest-high resolution computed tomography (HRCT) and others [1-4].
In the last decade, the six-minute-walk-test (6MWT) has been widely used to evaluate global exercise capacity in CF patients [5-7]. This low cost, easy-to-perform test is useful to guide therapy and for longitudinal assessment [8-11].
Although several studies have demonstrated significant correlation between 6MWT and other CF severity markers such as forced-expiratory-volume-in-one-second (FEV1) and body mass index (BMI) [5,9, 12,13,14], till now, only one study investigated the correlation between 6MWT and chest-HRCT [12].
Objective:
To evaluate the correlation between 6MWT, FEV1 and chest-HRCT in CF patients.
Methods:
A prospective cohort study was conducted at the Hadassah-CF Center. Demographic and anthropometric data (age, sex, CFTR genotype, BMI) were included. Spirometry and 6MWT were performed at the same routine visit and chest-HRCT, which was performed up to 1 year before/ after the day of the visit was scored according to the Brody score [16]. The 6MWT distances were transformed into Z scores (Z-6MWT) based on previous reports [17,18]. Analysis of correlations between FEV1, HRCT-Brody score and Z-6MWT were done.
Results:
Twenty-nine CF patients (14 females, mean age 21.9±6.5 years, mean BMI%ile 47.0 ±27.8), were included in the study. A significant correlation between Z-6MWT and FEV1 (r=0.39,r2=0.15,p=0.034) as well as between Z-6MWT and HRCT-Brody score (r=−0.38,r2=014,p=0.04) was found.
Conclusion:
The 6MWT is a non-invasive, inexpensive and efficient tool to assess the severity and progression of CF lung disease
