Reliability of maximal cardiopulmonary exercise testing in men with prostate cancer.
OBJECTIVE
To accurately assess exercise interventions and to evaluate acute and chronic cardiovascular effects in patients with early-stage cancer, consistently reliable functional outcome measures must be obtained. An incremental cardiopulmonary exercise test (CPET) with gas exchange measurement to assess peak oxygen consumption (V˙O2peak) provides the gold standard outcome of cardiorespiratory fitness.


METHODS
In the context of a randomized controlled trial, 40 patients with prostate cancer (mean age, 59 ± 7 yr) after radical prostatectomy performed two maximal CPET within 5.6 ± 5.5 d of each other. Incremental treadmill tests were performed in the morning under identical laboratory conditions. Reliability and within-subject variability from test 1 to test 2 for peak and submaximal variables were assessed by correlation coefficients, intraclass correlations (ICC), Bland-Altman plots, coefficient of variation, and paired t-tests.


RESULTS
There was high reliability between CPET for V˙O2peak (r = 0.92; P < 0.001; ICC, 0.900), ventilatory threshold (r = 0.88; P < 0.001; ICC, 0.927), minute ventilation-carbon dioxide production relation (V˙E/V˙CO2) (r = 0.86; P < 0.001; ICC, 0.850), and peak heart rate (r = 0.95; P < 0.001; ICC, 0.944). However, high within-subject variability was observed for all CPET parameters (mean coefficient of variation, 4.7%). Compared with those for test 1, significantly higher mean values were observed for V˙O2peak (27.0 ± 5.6 vs 28.1 ± 5.3 mL·kg·min, P < 0.05), ventilatory threshold (1.91 ± 0.5 vs 1.97 ± 0.4 L·min, P < 0.05), and V˙E/V˙CO2 (31.3 ± 5.8 vs 32.8 ± 3.4, P < 0.05) in test 2.


CONCLUSIONS
These findings indicate the presence of significant, and potentially clinically important, variability in CPET procedures in men with clinically localized prostate cancer and have important implications for the application and use of CPET to evaluate the efficacy of interventions to improve aerobic capacity in the oncology setting.
1Universities Space Research Association, Houston, TX; 2Duke University Medical Center, Durham, NC; 3Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, CANADA; and 4Cardiology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY.
Jessica M
JM
Scott
Whitney E
WE
Hornsby
Amy
A
Lane
Aarti A
AA
Kenjale
Neil D
ND
Eves
Lee W
LW
Jones
D000368:Aged; D005080:Exercise Test; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D010809:Physical Fitness / Q000502:physiology; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D011659:Pulmonary Gas Exchange; D012123:Pulmonary Ventilation; D015203:Reproducibility of Results