In 102 healthy Caucasians, 20-50 years old, we investigated the effect of anthropometrics on the 6-min walk test (6MWT), in order to provide reference values for walk distance (6MWD), oxygen saturation (SpO2), pulse rate (PR), respiratory rate (RR), breathlessness perception (VAS) and for the walking distance and body weight product (DW). The mean 6MWD and DW values were 593 +/- 57 and 638+/-44 m (P < 0.01) and 35,030 +/- 5306 and 48,882 +/- 6555 kg m (P < 0.01), respectively for women and for men. While walking, SpO2 remained unaltered and subjects reached 67 +/- 10% of their maximal predicted heart rate and a RR mean value of 19 +/- 4 bpm. VAS ratings were significantly higher in females as compared to males (24 +/- 15 vs. 18 +/- 5 mm, P < 0.05), however, when corrected for PR change while walking, they were not different. The equation by stepwise multiple regression analysis included height, age and gender for the 6MWD and accounted for 42% of the total variance. This study confirms the relevant effect of anthropometrics on walking capacity and suggests that when rating dyspnea, the change in heart rate during walking should be considered.

Background: In chronic obstructive pulmonary disease (COPD) patients, small-airway dysfunction (SAD) is considered a functional hallmark of disease. However, the exact role of SAD in the clinical presentation of COPD is not yet completely understood; moreover, it is not known whether SAD may have a relationship with the impact of disease. Objectives: To evaluate the prevalence of SAD among COPD patients categorized by the old and the new GOLD classification and to ascertain whether there is a relationship between SAD and impact of disease measured by the COPD Assessment Test (CAT) questionnaire. Methods: We prospectively enrolled COPD outpatients from the University Hospital of Parma. Using the impulse oscillometry system (IOS), we assessed the fall in resistance from 5 to 20 Hz (R5-R20), reactance at 5 Hz (X5), and resonant frequency (F_Res) as markers of peripheral airway dysfunction. According to R5-R20 ≥0.07 or <0.07, the cohort was also categorized in patients with and without SAD, respectively. Results: We studied 202 patients. In both GOLD classifications, a progressive increasing distribution of R5-R20 and F_Res was reported with a decreasing of X5. Moreover, there was a significant correlation between R5-R20 and CAT (r = 0.527, p < 0.001). Finally, the presence of SAD (OR 11.96; 95% CI 4.53-31.58; p < 0.001) and use of ICS + LABA + LAMA (OR 5.31; 95% CI 1.88-15.02; p = 0.002) were independent predictors of higher impact (CAT score ≥10). Conclusion: In COPD patients, the presence of SAD, as assessed by IOS, progressively increases with GOLD classifications and it is closely related to the high impact of disease on health status.

BACKGROUND:Patients with congestive heart failure or COPD may share an increased response in minute ventilation (V E ) to carbon dioxide output (V CO 2 ) during exercise. The goal of this study was to ascertain whether the V E /V CO 2 slope and V E /V CO 2 intercept can discriminate between subjects with congestive heart failure and those with COPD at equal peak oxygen uptake (V O 2 ). METHODS: We studied 46 subjects with congestive heart failure (mean age 61 ؎ 9 y) and 46 subjects with COPD (mean age 64 ؎ 8 y) who performed a cardiopulmonary exercise test. RESULTS: The V E /V CO 2 slope was significantly higher in subjects with congestive heart failure compared with those with COPD (39.5 ؎ 9.5 vs 31.8 ؎ 7.4, P < .01) at peak V O 2 < 16 mL/kg/min, but not > 16 mL/kg/min (28.3 ؎ 5.3 vs 28.9 ؎ 6.6). The V E /V CO 2 intercept was significantly higher in both subgroups of subjects with COPD compared with the corresponding values in the subjects with congestive heart failure (3.60 ؎ 1.7 vs ؊0.16 ؎ 1.7 L/min, P < .01; 3.63 ؎ 2.7 vs 0.87 ؎ 1.5 L/min, P < .01). According to receiver operating characteristic curve analysis, when all subjects with peak V O 2 < 16 mL/kg/min were considered, subjects with COPD had a higher likelihood to have the V E /V CO 2 intercept > 2.14 L/min (0.92 sensitivity, 0.96 specificity). Regardless of peak V O 2 , the end-tidal pressure of CO 2 (P ETCO 2 ) at peak exercise was not different in subjects with congestive heart failure (P ‫؍‬ .42) and was significantly higher in subjects with COPD (P < .01) compared with the corresponding unloaded P ETCO 2 . CONCLUSIONS: The ventilatory response to V CO 2 during exercise was significantly different between subjects with congestive heart failure and those with COPD in terms of the V E /V CO 2 slope with moderate-to-severe reduction in exercise capacity and in terms of the V E /V CO 2 intercept regardless of exercise capacity.

BackgroundPulmonary hyperinflation has the potential for significant adverse effects on cardiovascular function in COPD. The aim of this study was to investigate the relationship between dynamic hyperinflation and cardiovascular response to maximal exercise in COPD patients.MethodsWe studied 48 patients (16F; age 68 yrs ± 8; BMI 26 ± 4) with COPD. All patients performed spirometry, plethysmography, lung diffusion capacity for carbon monoxide (TLco) measurement, and symptom-limited cardiopulmonary exercise test (CPET). The end-expiratory lung volume (EELV) was evaluated during the CPET. Cardiovascular response was assessed by change during exercise in oxygen pulse (ΔO2Pulse) and double product, i.e. the product of systolic blood pressure and heart rate (DP reserve), and by the oxygen uptake efficiency slope (OUES), i.e. the relation between oxygen uptake and ventilation.ResultsPatients with a peak exercise EELV (%TLC) ≥ 75% had a significantly lower resting FEV1/VC, FEF50/FIF50 ratio and IC/TLC ratio, when compared to patients with a peak exercise EELV (%TLC) < 75%. Dynamic hyperinflation was strictly associated to a poor cardiovascular response to exercise: EELV (%TLC) showed a negative correlation with ΔO2Pulse (r = - 0.476, p = 0.001), OUES (r = - 0.452, p = 0.001) and DP reserve (r = - 0.425, p = 0.004). Furthermore, according to the ROC curve method, ΔO2Pulse and DP reserve cut-off points which maximized sensitivity and specificity, with respect to a EELV (% TLC) value ≥ 75% as a threshold value, were ≤ 5.5 mL/bpm (0.640 sensitivity and 0.696 specificity) and ≤ 10,000 Hg · bpm (0.720 sensitivity and 0.783 specificity), respectively.ConclusionThe present study shows that COPD patients with dynamic hyperinflation have a poor cardiovascular response to exercise. This finding supports the view that in COPD patients, dynamic hyperinflation may affect exercise performance not only by affecting ventilation, but also cardiac function.

FeNO measurements obtained by the new portable FeNO analyzer are reliable because they are directly comparable with those obtained by the stationary standard device. The use of portable instruments may facilitate the FeNO measurement in primary care.