Performance in the Glittre-ADL Test is Associated with the Pulmonary Function of Patients with Chronic Obstructive Pulmonary Disease.

The relationship between lung function and performance in some functional tests, as the six-minute walk test (6MWT) and Glittre-ADL test (TGlittre) are still discrepant in patients with chronic obstructive pulmonary disease (COPD). This study aimed to verify which test better correlates and is better explained by the pulmonary function, and which test better discriminates patients regarding the severity of the disease. Seventy-four patients with moderate to very severe COPD (54 men; 66 ± 9 years; FEV₁: 37.2 ± 14.3%pred) were included. Spirometry, 6MWT and TGlittre were performed. The results showed weak to moderate correlation between pulmonary function variables and 6MWT (0.36 ≤ r ≤ 0.45) and TGlittre (-0.44 ≤ r ≤ -0.53). In patients with performance of ≤400 m in the 6MWT, a strong correlation was observed between TGlittre with FEV₁ (%pred) (r = -0.82; p < .001). The pulmonary function variable that better predict the functional tests performance was FEV₁ (R² = 0.17). Both functional tests were able to discriminate patients with COPD GOLD 4 from the other classifications. When compared to GOLD 2 patients, GOLD 4 patients presented higher time spent on TGlittre (p < .001). When compared to GOLD 3 patients, GOLD 4 patients had higher TGlittre (p = .001). No statistical differences were found in the 6MWT between GOLD 3 and 4, as well as between GOLD 2 and 3. In conclusion, the pulmonary function presents stronger correlations and better explain the variability of TGlittre than of the 6MWT, especially in patients with greater functional impairment. The TGlittre seems to better discriminate patients with COPD regarding the severity of lung function.