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.