Browsing by Author "Xenophontos, Soteris"
Now showing 1 - 5 of 5
Results Per Page
Sort Options
- Peak aerobic capacity from incremental shuttle walk test in chronic kidney diseasePublication . Xenophontos, Soteris; Wilkinson, Thomas J.; Gould, Douglas W.; Watson, Emma L.; Viana, João L.; Smith, Alice C.Assessment of cardiorespiratory fitness is an important outcome in chronic kidney disease (CKD). We aimed to develop a predictive equation to estimate peak oxygen uptake (VO2peak ) and power output (WPeak ), as measured during a cardiopulmonary exercise test (CPET), from the distance walked (DW) during the incremental shuttle walk test (ISWT).
- Test–retest reliability, validation, and “minimal detectable change” scores for frequently reported tests of objective physical function in patients with non-dialysis chronic kidney diseasePublication . Wilkinson, Thomas J.; Xenophontos, Soteris; Gould, Douglas W.; Vogt, Barbara P.; Viana, João L.; Smith, Alice C.; Watson, Emma L.Physical function is an important outcome in chronic kidney disease (CKD). We aimed to establish the reliability, validity, and the "minimal detectable change" (MDC) of several common tests used in renal rehabilitation and research. In a repeated measures design, 41 patients with CKD not requiring dialysis (stage 3b to 5) were assessed at an interval of 6 weeks. The tests were the incremental shuttle walk test (ISWT), "sit-to-stand" (STS) test, estimated 1 repetition maximum for quadriceps strength (e1RM), and VO2peak by cardiopulmonary exercise testing (CPET). Reliability was assessed using intraclass correlation coefficient and Bland-Altman analysis, and absolute reliability by standard error of measurement and MDC. The ISWT, STS-60, e1RM, and CPET had "good" to "excellent" reliability (0.973, 0.927, 0.927, and 0.866), respectively. STS-5 reliability was poor (0.676). The MDC is ISWT, 20 m; STS-5, 7.5 s; STS-60, 4 reps; e1RM, 6.4 kg; VO2peak, 2.8 ml/kg/min. There was strong correlation between the ISWT and VO2peak (r = 0.73 and 0.74). While there was poor correlation between the STS-5 and e1RM (r = 0.14 and 0.47), better correlation was seen between STS-5 and ISWT (r = 0.55 and 0.74). In conclusion, the ISWT, STS-60, e1RM, and CPET are reliable tests of function in CKD. The ISWT is a valid means of exercise capacity. The MDC can help researchers and rehabilitation professionals interpret changes following an intervention.
- Twelve weeks of supervised exercise improves self-reported symptom burden and fatigue in chronic kidney disease: a secondary analysis of the ‘ExTra CKD’ trialPublication . Wilkinson, Thomas J; Watson, Emma L; Gould, Douglas W; Xenophontos, Soteris; Clarke, Amy L; Vogt, Barbara P; Viana, João L; Smith, Alice CChronic kidney disease (CKD) patients experience a high symptom burden including fatigue, sleep difficulties, muscle weakness and pain. These symptoms reduce levels of physical function (PF) and activity, and contribute to poor health-related quality of life (HRQoL). Despite the gathering evidence of positive physiological changes following exercise in CKD, there is limited evidence on its effect on self-reported symptom burden, fatigue, HRQoL and physical activity.
- Twelve-week combined resistance and aerobic training confers greater benefits than aerobic training alone in nondialysis CKDPublication . Watson, Emma L.; Gould, Douglas W.; Wilkinson, Thomas J.; Xenophontos, Soteris; Clarke, Amy L.; Vogt, Barbara Perez; Viana, João L.; Smith, Alice C.There is a growing consensus that patients with chronic kidney disease (CKD) should engage in regular exercise, but there is a lack of formal guidelines. In this report, we determined whether combined aerobic and resistance exercise would elicit superior physiological gains, in particular muscular strength, compared with aerobic training alone in nondialysis CKD. Nondialysis patients with CKD stages 3b-5 were randomly allocated to aerobic exercise {AE, n = 21; 9 men; median age 63 [interquartile range (IQR) 58-71] yr; median estimated glomerular filtration rate (eGFR) 24 (IQR 20-30) ml·min-1·1.73 m-2} or combined exercise [CE, n = 20, 9 men, median age 63 (IQR 51-69) yr, median eGFR 27 (IQR 22-32) ml·min-1·1.73 m-2], preceded by a 6-wk run-in control period. Patients then underwent 12 wk of supervised AE (treadmill, rowing, or cycling exercise) or CE training (as AE plus leg extension and leg press exercise) performed three times per week. Outcome assessments of knee extensor muscle strength, quadriceps muscle volume, exercise capacity, and central hemodynamics were performed at baseline, following the 6-wk control period, and at the end of the intervention. AE and CE resulted in significant increases in knee extensor strength of 16 ± 19% (mean ± SD; P = 0.001) and 48 ± 37% ( P < 0.001), respectively, which were greater after CE ( P = 0.02). AE and CE resulted in 5 ± 7% ( P = 0.04) and 9 ± 7% ( P < 0.001) increases in quadriceps volume, respectively ( P < 0.001), which were greater after CE ( P = 0.01). Both AE and CE increased distance walked in the incremental shuttle walk test [28 ± 44 m ( P = 0.01) and 32 ± 45 m ( P = 0.01), respectively]. In nondialysis CKD, the addition of resistance exercise to aerobic exercise confers greater increases in muscle mass and strength than aerobic exercise alone.
- Ultrasound assessment of muscle mass in response to exercise training in chronic kidney disease: a comparison with MRIPublication . Gould, Douglas W.; Watson, Emma L.; Wilkinson, Thomas J.; Wormleighton, Joanne; Xenophontos, Soteris; Viana, Joao L.; Smith, Alice C.Chronic kidney disease (CKD) is a catabolic condition associated with muscle wasting and dysfunction, which associates with morbidity and mortality. There is a need for simple techniques capable of monitoring changes in muscle size with disease progression and in response to interventions aiming to increase muscle mass and function. Ultrasound is one such technique; however, it is unknown how well changes in muscle cross-sectional area (CSA) measured using ultrasound relate to changes in whole muscle volume measured using magnetic resonance imaging. We tested whether rectus femoris CSA (RF-CSA) could be used as a valid indication of changes in quadriceps muscle volume as a single measure of muscle size and following a 12 week exercise intervention that resulted in muscle hypertrophy.