584 research outputs found
POLKEY M.: ‘Does physical inactivity cause chronic obstructive pulmonary disease
No full textA B S T R A C T COPD (chronic obstructive pulmonary disease) is the most common pulmonary disease and is the only common cause of death in which mortality is presently rising. It is caused by the inhalation of smoke, which leads to oxidative stress and inflammation both in the lungs and systemically. Reduced physical activity is a well-recognized consequence of the condition, but we argue here that inactivity is itself an early cause of lung function decline and symptoms. This hypothesis is supported by data from population studies that link activity levels to decline in spirometric indices, both in smokers and non-smokers. In addition, smokers with low physical activity levels are more likely to be diagnosed subsequently with COPD. Physical exercise reduces oxidative stress, has an anti-inflammatory effect and reduces the frequency of upper respiratory tract infections, providing a number of mechanisms by which it could attenuate the harmful effects of smoking. There is sufficient evidence to justify population trials of lifestyle interventions aimed at improving physical activity levels and reducing lung function decline in people diagnosed with early COPD through spirometry screening
Supplemental Material - Strategies to deliver smoking cessation interventions during targeted lung health screening - a systematic review and meta-analysis
No full textSupplemental Material for Strategies to deliver smoking cessation interventions during targeted lung health screening - a systematic review and meta-analysis by Parris J Williams, Keir EJ Philip, Saeed M Alghamdi, Alexis M Perkins, Sara C Buttery, Michael I Polkey, Anthony A Laverty, and Nicholas S Hopkinson in Chronic Respiratory Disease.</p
Acute dietary nitrate supplementation and exercise performance in COPD: a double-blind, placebo-controlled, randomised controlled pilot study
No full textBackground: Dietary nitrate supplementation can enhance exercise performance in healthy people, but it is not clear if it is beneficial in COPD. We investigated the hypotheses that acute nitrate dosing would improve exercise performance and reduce the oxygen cost of submaximal exercise in people with COPD.Methods: We performed a double-blind, placebo-controlled, cross-over single dose study. Subjects were randomised to consume either nitrate-rich beetroot juice (containing 12.9mmoles nitrate) or placebo (nitrate-depleted beetroot juice) 3 hours prior to endurance cycle ergometry, performed at 70% of maximal workload assessed by a prior incremental exercise test. After a minimum washout period of 7 days the protocol was repeated with the crossover beverage.Results: 21 subjects successfully completed the study (age 68±7years; BMI 25.2±5.5kg/m2; FEV1 percentage predicted 50.1±21.6%; peak VO2 18.0±5.9ml/min/kg). Resting diastolic blood pressure fell significantly with nitrate supplementation compared to placebo (-7±8mmHg nitrate vs. -1±8mmHg placebo; p = 0.008). Median endurance time did not differ significantly; nitrate 5.65 (3.90–10.40) minutes vs. placebo 6.40 (4.01–9.67) minutes (p = 0.50). However, isotime oxygen consumption (VO2) was lower following nitrate supplementation (16.6±6.0ml/min/kg nitrate vs. 17.2±6.0ml/min/kg placebo; p = 0.043), and consequently nitrate supplementation caused a significant lowering of the amplitude of the VO2-percentage isotime curve.Conclusions: Acute administration of oral nitrate did not enhance endurance exercise performance; however the observation that beetroot juice caused reduced oxygen consumption at isotime suggests that further investigation of this treatment approach is warranted, perhaps targeting a more hypoxic phenotype.Trial Registration: ISRCTN Registry ISRCTN6609913
Whistle mouth pressure, as a measure of expiratory muscle strength in patients with amyotrophic lateral sclerosis
No full textExercise response to oxygen supplementation is not associated with survival in hypoxemic patients with obstructive lung disease
No full textAhmed S Sadaka,1,3 Andrew J Montgomery,2 Sahar M Mourad,3 Michael I Polkey,1 Nicholas S Hopkinson1 1NIHR Respiratory Biomedical Research Unit at the Royal Brompton Hospital and Imperial College, Respiratory Medicine, London, UK; 2Royal Brompton and Harefield NHS Foundation Trust, London, UK; 3Alexandria University Faculty of Medicine, Chest Department, Alexandria, Egypt Purpose: Hypoxemia is associated with more severe lung disease and worse outcomes. In some patients with chronic obstructive lung diseases who desaturate on exertion, supplemental oxygen improves exercise capacity. The clinical significance of this exercise response to oxygen supplementation is not known.Patients and methods: We identified chronic obstructive lung disease patients at our center who underwent a 6-minute walking test (6MWT) for ambulatory oxygen assessment and who desaturated breathing air and therefore had an additional walk test on supplemental oxygen, between August 2006 and June 2016. Responders were defined as walking ≥26 m further with oxygen. Survival was determined up to February 1, 2017. We compared survival in oxygen responders and nonresponders in patients with obstructive lung diseases.Results: One hundred and seventy-four patients were included in the study, median age 70 years. Seventy-seven (44.3%) of the patients were oxygen responders. Borg dyspnea score improved by 1.4 (±1.4) units (P<0.0005) on oxygen. Median survival was 66 months with death occurring in 84 (48.2%) patients. Kaplan–Meier analysis revealed no survival difference between both responders and nonresponders (P=0.571). Cox regression analysis showed that more 6MWT desaturation, lower 6-minute walking distance on room air, male gender, lower hemoglobin, and body mass index were associated with higher mortality risk.Conclusion: Acute exercise response to supplemental oxygen is not associated with long-term survival in patients with obstructive lung disease. This supports the use of ambulatory oxygen treatment for symptomatic purposes only. Keywords: 6-minute walking test, exercise, hypoxemia, obstructive lung disease, oxyge
Vitamin D and skeletal muscle strength and endurance in COPD.
No full textFree fulltext available on publishers website. DOI: 10.1183/09031936.00043112Jackson, A, Shrikrishna, D, Kelly, J, Kemp, S, Hart, N, Moxham, J, Polkey, M, Kemp, P, & Hopkinson, N 2013, 'Vitamin D and skeletal muscle strength and endurance in COPD', The European Respiratory Journal, 41, 2, pp. 309-316
Aerosol transmission of SARS-CoV-2: inhalation as well as exhalation matters
No full textImperial College Clinician Investigator Scholarshi
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