29 research outputs found
Exercise testing in cystic fibrosis:who and why?
Get PDFAnnual review exercise testing is recommended by the Cystic Fibrosis (CF) Trust. Testing to date has focused on evaluating aerobic fitness, a key prognostic indicator. Tests available range from simple field tests, to comprehensive evaluations of aerobic exercise (dys)function – cardiopulmonary exercise testing (CPET).‘Field tests’, although easy to perform are limited in the information they provide. Whereas CPET, the ‘gold standard’ measure of aerobic fitness, is recommended as the first choice exercise test by the European CF Society Exercise Working Group. CPET offers a precise cardiovascular, respiratory and metabolic evaluation of exercise capacity, including assessment of mechanism(s) of exercise limitation
Exercise testing and training in cystic fibrosis clinics in the United Kingdom: a 10-year update
Get PDFThis is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record
168 A protocol to determineVO<sub>2max</sub> in young patients with cystic fibrosis:recommendations for clinical practice
No full textWS16.2 the reliability of maximal cardiopulmonary exercise testing for young cystic fibrosis patients
No full textBackground: Maximal cardiopulmonary exercise testing (CPET) is the most precise method for evaluating physical function of patients with mild-to-moderate cystic fibrosis (CF). This study sought to establish the between trial variation of CPET parameters across three different time points. Methods: Fourteen 7−18 year olds (10 male) completed an incremental ramp cycle test to exhaustion. Peak oxygen uptake (V˙ O2peak), power output (Wpeak), heart rate (HRpeak ) and end-exercise oxygen saturation (SaO2%) and breathlessness (RPD) were determined. Following 15-min recovery supramaximal exercise to exhaustion was performed at a work rate (WR) equal to 110% ramp Wpeak (T1). Testing was repeated 48 h (T2) and 4−6 weeks later (T3). Intra-class retest correlations, change in the mean score [V˙ O2peak] and the typical error for all measurements assessed reliability. Results: Intra-class correlations ranged from r = 0.57–0.99 and were highest for WR. No significant differences in mean (SD) V˙ O2peak were found between T1-T2; 1.91 (0.80) and 1.93 (0.66) L×min−1, p = 0.79; T2-T3 1.81 (0.48) and 1.68 (0.50) L×min−1, n = 13, p = 0.20 and T1-T3 1.77 (0.63) and 1.68 (0.50) L×min−1, n = 13, p = 0.25, respectively. The highest typical error for HRpeak (T1-T2), WR (T2-T3), RPD (T1-T2), SaO2% (T2-T3), and V˙ O2peak (T1-T2) were 12, 9.3, 1.4, 1.3 and 0.3%, respectively. Conclusion: CPET derived variables especially V˙ O2peak are highly reproducible between 1 and 42 days. Clinicians can have confidence in precisely reproducing the effect of exercise/pharmacological interventions or CF disease on parameters obtained during CPET. Acknowledgments: Supported by the Peninsula NIHR Research Facility
Ketone monoester ingestion improves cardiac function in adults with type 2 diabetes: a double-blind, placebo controlled, randomised, crossover trial
No full textType 2 diabetes (T2D) is a metabolic disease associated with cardiovascular dysfunction. The myocardium preferentially uses ketones over free fatty acids as a more energy efficient substrate. The primary aim was to assess the effects of ketone monoester (Kme) ingestion on cardiac output index (Q̇i). Secondary aims were to assess the effects of Kme ingestion on markers of cardiac haemodynamics, muscle oxygenation and vascular function at rest, during and following step-incremental cycling.We undertook a double-blind, randomised, crossover design study in 13 adults (age, 66±10 y; BMI, 31.3±7.0 kg·m−2) with T2D. Participants completed two conditions, where they ingested a Kme (0.115 g‧kg−1) or a placebo taste-mathced drink. Cardiac function was measured using thoracic impedance cardiography and muscle oxygenation of the calf was determined via near-infrared spectroscopy. Macrovascular endothelial function was measured by flow mediated dilation (FMD) and microvascular endothelial function was measured via transdermal delivery of acetylcholine (ACh) and insulin. Circulating β-hydroxybutyrate [β-Hb] was measured throughout.Kme ingestion raised circulating β-Hb throughout the protocol (peak 1.9 mM; P=0.001 vs. placebo). Kme ingestion increased Q̇i by 0.75±0.5 L∙min−1∙m−2 (P=0.003) stroke volume index by 7.2±4.5 mL∙m−2 (P=0.001), and peripheral muscle oxygenation by 9.9±7.1% (P=0.001) and reduced systemic vascular resistance index by-420±-225 dyn∙s−1∙cm−5∙m−2 (P=0.031) compared to placebo condition. There were no differences between Kme and placebo in heart rate (P=0.995), FMD (P=0.542), ACh max (P=0.800), insulin max (P=0.242).Ingestion of Kme improved Q̇i, stroke volume index and peripheral muscle oxygenation, but did not alter macro- or microvascular endothelial function in people with T2D.<br/
WS01.02 The current state of play regarding exercise testing in cystic fibrosis: co-development with the community
No full textObjectives: functional exercise testing of people with cystic fibrosis (CF) in clinical practice still lacks global standardisation in both choice of test and test conduct. A representative group from the European CF Society Exercise Working Group (ECFS-EWG), including members from the Physiotherapy Special Interest Group (PhySIG), are aiming to develop guidance and standard operating procedures for an agreed selection of exercise tests, that allow for the comprehensive functional evaluation of people with CF.Methods: to facilitate test recommendations, an international panel (n = 64; 81.3% Europe), comprising physicians (5%), exercise scientists (14%), physiotherapists (78%), physiotherapy assistants and fitness instructors (3%), were consulted to obtain a snapshot of current practice.Results: in the last two years, 90.6% of respondents reported using exercise tests, the most common of which were the 6-minute walk test (6 MWT; 79.4%), cycle ergometer cardiopulmonary exercise testing with gas analysis (CPET, 52.4%), the 1-minute sit-to-stand test (1 minSTS; 39.7%), cycle ergometer tests without gas analysis (30.2%) and the 15-level 10-m modified shuttle test (28.6%). When asked to rank exercise tests (excluding the accepted gold standard CPET) based on perceptions of those most rigorously validated, the top 5 were: 1) cycle ergometer tests without gas analysis, 2) treadmill tests without gas analysis, 3) 6 MWT, 4) 1 minSTS and 5) the A-step test.Conclusions: this multidisciplinary panel has aided the construction of a hierarchy of the most-used and best-validated exercise tests for people with CF. The high rate of utilisation of the 6 MWT, even in mild CF disease where a ceiling effect can be observed, highlights the need for better guidance regarding the other simple alternatives to CPET when evaluating the functional capacity of people with CF. Peripheral muscle testing is rarely used and more research is needed to determine the clinimetric properties of tests
Measurement of V̇O2<sub>max</sub> in clinical groups is feasible and necessary
Get PDFThis is the author accepted manuscript. The final version is available from American Physiological Society via the DOI in this record
WS08.1 The utility of oxygen uptake efficiency as a marker of aerobic fitness in children with cystic fibrosis
No full textThis is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record
Validity and reliability concerns associated with cardiopulmonary exercise testing young people with cystic fibrosis
No full textThis is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Letter to the Edito
Relationship between (non)linear phase II pulmonary oxygen uptake kinetics with skeletal muscle oxygenation and age in 11-15 year olds
Get PDFThis is the author accepted manuscript. the final version is available from Wiley via the DOI in this recordThis study investigated in nineteen male youth (mean age: 13.6 ± 1.1 y, range: 11.7 –
15.7 y) the relationship between pulmonary oxygen uptake ( o2) and muscle
deoxygenation kinetics during moderate‐ and very heavy‐intensity ‘step’ cycling
initiated from unloaded pedaling (i.e. U→M and U→VH) and moderate‐to‐very heavy‐
intensity step cycling (i.e. M→VH). Pulmonary o2 was measured breath‐by‐breath and
tissue oxygenation index (TOI) of the vastus lateralis using near‐infrared spectroscopy.
There were no significant differences in the phase II time constant (τ o2p) between
U→M and U→VH (23 ± 6 s vs. 25 ± 7 s; P = 0.36); however, the τ o2p was slower during
M→VH (42 ± 16 s) compared to other conditions (P < 0.001). Quadriceps TOI decreased
with a faster (P < 0.01) mean response time (MRT; i.e. time delay + τ) during U→VH (14
± 2 s) compared to U→M (22 ± 4 s) and M→VH (20 ± 6 s). The difference (Δ) between
the τ o2p and MRT‐TOI was greater during U→VH compared to U→M (12 ± 7 vs. 2 ± 7 s,
P < 0.001) and during M→VH (23 ± 15 s) compared to other conditions (P < 0.02),
suggesting an increased proportional speeding of fractional O2 extraction. The slowing
of the τ o2p during M→VH relative to U→M and U→VH correlated positively with
chronological age (r = 0.68 and 0.57, respectively, P < 0.01). In youth, “work‐to‐work”
transitions slowed microvascular O2 delivery‐to‐O2 utilization with alterations in phase
II o2 dynamics accentuated between the ages of 11 to 15 y
