Supervisors info:
Φιλίππου Αναστάσιος, Αναπληρωτής Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Γράψα Ειρήνη, Αναπληρώτρια Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Θεόδωρος Πιτταράς, Επίκουρος Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Summary:
ABSTRACT
Background: Cardiopulmonary function and physical fitness play an important role in anindividual’sactivities of daily livingand they are strictly related to the quality of life. Due to their underlying disease and their sedentary lifestyle, hemodialysis patients with Chronic Kidney Disease (CKD) have a reduced cardiopulmonary capacity and, therefore, reduced ability to exercise. On the other hand, research has revealed that exercise (aerobic and strength training) could be beneficial for those patients in multiple ways. Cardiopulmonary exercise testing (CPET) is a reliable method for the assessment of cardiopulmonary function and the ability to exercise and is fundamental in designing a personalized exercise program. The aim of this study is to analyze the cardiopulmonary function and endurance of ambulatory hemodialysis patients by using CPET, comparing these parameters with those of 10 healthy age-matched individuals, in order to characterize the functional profile of those patients regarding their ability to exercise and, thus, to prospectively contribute to the development of appropriate exercise programs as part of their treatment strategy.
Methods: The sample of this study consists of 10 ambulatory hemodialysis patients with CKD (6 females and 4 males, age: 59.50±16.56 years, mean duration of hemodialysis treatment: 4.45±2.7 years), who did not exercise regularly. Patients were assessed (CPET), on a day between their scheduled dialysis sessions using a cycle ergometer and a ramp exercise protocol (i.e., gradual increase of work rate).The results of these evaluations were further compared with the corresponding results of CPET in 10 (3 females and 7 males) healthy age-matched participants who did not exercise regularly as well (58.40± 10.52 years).
Results: All participants completed CPET without any complications. The total time of CPET for the group with CKD was 6.43±1.33 min, the maximum work was 60.50±31.75 watt corresponding to 42.80±16.85 % of the predicted work. There was a significant difference in the corresponding values with the group of healthy participants, which were 8.21±1.67 minutes (p= 0.017), 123.5±46.61 watt (p=0.002) and 76.8±21.12 % (p=0.001). A reduced mean VO2peak (VO2peak: 14.4±4.5 ml/kg/min, and % of VO2peak predicted: 56.10±16.93 %) and Anaerobic Threshold (AT: 10.93±2.39 ml/kg/min, and %, of AT predicted: 43.50±11.92 %) was observed in all patients with CKD. All the above variables were significantly different compared with those in the group of healthy participants: VO2peak: 25.92±7.11 ml/kg/min (p= 0.000) and % of VO2peak predicted: 95.4±20.47 % (p=0.000), AT: 18.33±2.63 ml/kg/min (p=0.000) and % of AT predicted: 67.3±10.9 % (p=0.001), respectively. The values of respiratory variables were found not to be significantly different compared to the predicted ones for the group with CKD: FEV1: 2.39±0.88 L, % of FEV1 predicted: 93.33±21.60 %, and FVC: 3.08±1.00 L, % of FVC predicted: 99.22±23.52 %, while the ratio FEV1/FVC was 76.77±5.20, while for the group of healthy participants the respective values were: FEV1: 3.19±0.76 L (p= 0.048), % of FEV1 predicted: 105.3±19.69 % (p= 0.223), and FVC: 4.09±1.01 L (p= 0.042), % of FVC predicted: 108.9±21.3 % (p= 0.360), and the ratio FEV1/FVC: 78.4±6.6 (p= 0.537). In addition, a significant difference was found between the two groups in the following variables HRmax: 125.1±26.28 bpm, % of HRmax predicted: 74.43±14.26 %, O2 pulse: 7.18±1.49 ml/beat, VE: 40.96±13.89 l/min, BR: 47.1±16.75 %, and VO2/t slope: 0.39±0.22, for the group with CKD, compared to the group of healthy participants: HRmax: 152±21.78 bpm (p= 0.023), % of HRmax predicted: 94.7±10.97 % (p= 0.005), O2 pulse: 13.85±3.99 ml/beat (p= 0.000), VE:85.38±25.23 l/min (p=0.000), BR: 20.6±10.63 % (p=0.001), and VO2/t slope: 0.94±0.43 (p=0.003). Finally, no significant differences were found between the two groups regarding VE/VCO2 (28.0±3.98 for the group with CKD compared with 26.75±3.99 in the healthy group, p= 0.491) and recover 1’ (18.22±9.7 bpm for the group with CKD compared with 22.7±8.6 bpm in the healthy group, p=0.301). Systolic and diastolic blood pressure, as well as SPO2 lay within the normal range both before and after CPET in both groups.
Conclusion: Ambulatory hemodialysis patients with CKD exhibit a reduced cardiopulmonary function due to possible underlying cardiopulmonary disorders and other factors that lead them to reduced physical activity. The poor physical condition of those patients has been associated with poor quality of life and reduced survival expectancy. CPET is a useful tool for the assessment of the cardiopulmonary function of hemodialysis patients with CKD and for the subsequent design of personalized exercise programs for them.
Keywords:
CPET, Cpet, Ergospirometry, Dialysis, Hemodialysis patients, CKD, Renal disease, Renal insufficiency, Exercise, Cardiorespiratory function, Cardiopulmonary function, Abulatory patients, Exercise capacity profile, Exercise.
