Relationship between exercise test recovery indices and psychological and quality-of-life status in hemodialysis patients: a pilot study.

BACKGROUND The aim of this study was to correlate the psychological and health-related quality-of-life status of hemodialysis (HD) patients with recovery indices following maximal and submaximal exercise tests. METHODS Twenty patients on HD (aged 53.5 ± 12.9 years) and 18 healthy individuals (aged 54.1 ± 10.2 years) underwent a maximal and a submaximal cardiopulmonary test (CPETmax and CPETsubmax). Heart rate recovery (HRrec) 1 minute after exercise and time for VO2 to decrease by half (T1/2VO2) were determined. All subjects also completed 3 questionnaires: (a) the Beck Depression Inventory (BDI), (b) Quality of Life Index (QLI)-Spitzer Index and (c) SF-36 physical and mental component summary scales. RESULTS HRrec after maximal (p=0.029) and submaximal test (p=0.041) was found to be lower in patients compared with healthy individuals. T1/2VO2 was raised by 29% (p=0.003) in patients compared with controls. Moreover, a significantly higher BDI (by 133.7%), lower SF-36 physical (by 47.8%) and mental (by 42.9%) component summary score and lower QLI (by 32.1%) results were found in HD patients compared with controls. BDI (p=0.045), QLI (P=0.011), SF-36 physical (p=0.017) and mental component scales (p=0.021) were independently associated with HRrec in maximal tests in patients. Similar correlations remained for submaximal tests among HRrec and BDI (p=0.004), QLI (p=0.006), SF-36 physical (p=0.048) but not mental scales (p=0.369) in the patients' group. T1/2VO2 also correlated to BDI (p=0.019), QLI (p=0.005) and SF-36 mental scale (p=0.017) in maximal tests in these patients. In contrast, there was a correlation between HRrec and BDI (p=0.004) in the control group for maximal tests only. CONCLUSIONS In conclusion, in HD patients, recovery indices following maximal and submaximal exercise tests were shown to provide useful indications of the patients' psychological and quality-of-life profiles.