Project description:Key pointsPeak oxygen uptake, a primary determinant of prognosis, mortality and quality of life, is diminished in patients with chronic obstructive pulmonary disease (COPD), with mounting evidence supporting an important role for peripheral dysfunction, particularly within skeletal muscle. In patients with severe COPD and activity-matched controls, muscle oxygen transport and utilization were assessed at peak effort during single-leg knee-extensor exercise (KE), where ventilation is assumed to be submaximal. This strategy removes ventilation as the major constraint to exercise capacity in COPD, allowing maximal muscle function to be attained and evaluated. During maximal KE, both convective arterial oxygen delivery to the skeletal muscle microvasculature and subsequent diffusive oxygen delivery to the mitochondria were diminished in patients with COPD compared to control subjects. These findings emphasize the importance of factors, beyond the lungs, that influence exercise capacity in this patient population and may, ultimately, influence the prognosis, mortality and quality of life for patients with COPD.AbstractPeak oxygen uptake ( V̇O2peak ), a primary determinant of prognosis, mortality and quality of life, is diminished in patients with chronic obstructive pulmonary disease (COPD). Mounting evidence supports an important role of the periphery, particularly skeletal muscle, in the diminished V̇O2peak with COPD. However, the peripheral determinants of V̇O2peak have not been comprehensively assessed in this cohort. Thus, the hypothesis was tested that both muscle convective and diffusive oxygen (O2 ) transport, and therefore skeletal muscle peak O2 uptake ( V̇MO2peak ), are diminished in patients with COPD compared to matched healthy controls, even when ventilatory limitations (i.e. attainment of maximal ventilation) are minimized by using small muscle mass exercise. Muscle O2 transport and utilization were assessed at peak exercise from femoral arterial and venous blood samples and leg blood flow (by thermodilution) in eight patients with severe COPD (forced expiratory volume in 1s (FEV1 ) ± SEM = 0.9 ± 0.1 l, 30% of predicted) and eight controls during single-leg knee-extensor exercise. Both muscle convective O2 delivery (0.44 ± 0.06 vs. 0.69 ± 0.07 l min-1 , P < 0.05) and muscle diffusive O2 conductance (6.6 ± 0.8 vs. 10.4 ± 0.9 ml min-1 mmHg-1 , P < 0.05) were ∼1/3 lower in patients with COPD than controls, resulting in an attenuated V̇MO2peak in the patients (0.27 ± 0.04 vs. 0.42 ± 0.05 l min-1 , P < 0.05). When cardiopulmonary limitations to exercise are minimized, the convective and diffusive determinants of V̇MO2peak , at the level of the skeletal muscle, are greatly attenuated in patients with COPD. These findings emphasize the importance of factors, beyond the lungs, that may ultimately influence this population's prognosis, mortality and quality of life.
Project description:Diaphragm muscles in Chronic Obstructive Pulmonary Disease (COPD) patients undergo an adaptive fast to slow transformation that includes cellular adaptations. This project studies the signaling mechanisms responsible for this transformation. Keywords: other
Project description:Chronic obstructive pulmonary disease (COPD) is a progressive and debilitating respiratory condition that leads to significant burden, both medically and financially. It affects millions of people worldwide and causes significant morbidity and mortality. Most detailed information related to its prevalence, morbidity, and mortality comes from high-income countries, but 90% of COPD-related deaths occur in low- and middle-income countries. Cigarette smoking is the main risk factor for developing COPD, but other risk factors do exist and need to be recognized. A majority of morbidity and mortality as well as health care costs occur from acute exacerbations of COPD with a known phenotype of patients being "frequent exacerbators." Health care costs for COPD are not only from treatment of exacerbations, such as hospitalization, but also medication costs for maintenance therapy and outpatient treatment. COPD has been linked with many comorbidities leading to significant burden of disease. The goal of this review is to evaluate the overall burden of disease including prevalence, morbidity, mortality, health care costs, and economic costs.
Project description:Investigation of whole genome gene expression level changes of the dynamic gene profiling of peripheral blood mononuclear cells (PBMCs) from patients with AECOPD) on day1, 3 and 10, compared to the normal people and stable COPD patients. A five chip study using total RNA recovered from Peripheral Blood Mononuclear Cell of Peripheral Blood.Evaluating the dynamic gene profiling of peripheral blood mononuclear cells (PBMCs) from patients with AECOPD) on day1, 3 and 10 after the hospital admission, to compared with healthy controls or patients with stable COPD. Slides were scanned at 5 μm/pixel resolution using an Axon GenePix 4000B scanner (Molecular Devices Corporation) piloted by GenePix Pro 6.0 software (Axon). Scanned images (TIFF format) were then imported into NimbleScan software (version 2.5) for grid alignment and expression data analysis. Expression data were normalized through quantile normalization and the Robust Multichip Average (RMA) algorithm included in the NimbleScan software. The Probe level (*_norm_RMA.pair) files and Gene level (*_RMA.calls) files were generated after normalization.
Project description:Rationale: Chronic obstructive pulmonary disease (COPD) is a prevalent respiratory disease lacking disease modifying treatment. The role of CXCL12/CXCR4 axis has been demonstrated in acute exacerbation of COPD. The interest of study early COPD has been recently pointed out. Objectives: To study the role of the CXCL12/CXCR4 axis in both human and mouse model of early COPD. Methods: Blood and lung tissue were obtained from both COPD patients and mice exposed to cigarette smoke (CS) for 10 weeks and intranasal instillations of polyinosinic–polycytidylic acid (poly(I:C)) to mimic exacerbations for 5 weeks. Measurements and Main Results: Exposed mice presented mild airway obstruction, peri-bronchial fibrosis and right heart remodeling. The level of CXCR4 expressing cells was increased in the blood of exposed mice, as well as in the blood of patients with mild COPD. Lung CXCL12 expression was higher both in exposed mice and COPD patients. The densities of fibrocytes expressing CXCR4 were increased in the blood and in the bronchial submucosa of exposed mice. Conditional inactivation of CXCR4 at adult stage as well as pharmacological inhibition of CXCR4 with plerixafor injections improved lung function and inflammation and protected against CS and poly-(I:C)-induced airway and cardiac remodeling. CXCR4-/- and plerixafor-treated mice also had reduced levels of CXCR4-expressing circulating cells and a lower density of peri-bronchial fibrocytes. Conclusions: We demonstrated that targeting CXCR4 has beneficial effects in an animal model of early COPD, and provide a framework to translate preclinical findings to clinical settings within a drug repurposing approach.
Project description:BackgroundOnly a few studies have evaluated the radiologic features of pre-existing structural abnormalities where lung cancer may develop. This study aimed to analyze the computed tomography (CT) images of lung areas where new cancer developed in chronic obstructive pulmonary disease (COPD) patients.Patients and methodsWe conducted a multicenter, longitudinal cohort study, called the Keio COPD Comorbidity Research, to assess the incidence of lung cancer. Emphysema and interstitial abnormalities were evaluated in 240 COPD patients who had baseline CT scans applicable for further digital analyses. For patients who developed lung cancer during the 3-year follow-up period, the local spherical lung density of the precancerous area was individually quantified.ResultsLung cancer was newly diagnosed in 21 participants (2.3% per year). The percent-age of low attenuation area in patients who developed lung cancer was higher than that of the other patients (20.0% vs 10.4%, P=0.014). The presence of emphysema (odds ratio [OR] 4.2, 95% confidence interval [CI] 1.0-29.0, P=0.049) or interstitial lung abnormalities (OR 15.6, 95% CI 4.4-65.4, P<0.0001) independently increased the risk for lung cancer. Compared with the density of the entire lung, the local density of the precancerous area was almost the same in patients with heterogeneous emphysema, but it was higher in most patients with interstitial abnormalities.ConclusionThe presence of emphysema or interstitial abnormalities or a combination of both were independent predictors of lung cancer development in COPD patients. Furthermore, lung cancer most often developed in non-emphysematous areas or in interstitial abnormalities.
Project description:COPD is a major cause of disability, but little is known about how disability develops in this condition.The authors analysed data from the Function, Living, Outcomes and Work (FLOW) Study which enrolled 1202 Kaiser Permanente Northern California members with COPD at baseline and re-evaluated 1051 subjects at 2-year follow-up. The authors tested the specific hypothesis that the development of specific non-respiratory impairments (abnormal body composition and muscle strength) and functional limitations (decreased lower extremity function, poor balance, mobility-related dyspnoea, reduced exercise performance and decreased cognitive function) will determine the risk of disability in COPD, after controlling for respiratory impairment (FEV(1) and oxygen saturation). The Valued Life Activities Scale was used to assess disability in terms of a broad range of daily activities. The primary disability outcome measure was defined as an increase in the proportion of activities that cannot be performed of 3.3% or greater from baseline to 2-year follow-up (the estimated minimal important difference). Multivariable logistic regression was used for analysis.Respiratory impairment measures were related to an increased prospective risk of disability (multivariate OR 1.75; 95% CI 1.26 to 2.44 for 1 litre decrement of FEV(1) and OR 1.57 per 5% decrement in oxygen saturation; 95% CI 1.13 to 2.18). Non-respiratory impairment (body composition and lower extremity muscle strength) and functional limitations (lower extremity function, exercise performance, and mobility-related dyspnoea) were all associated with an increased longitudinal risk of disability after controlling for respiratory impairment (p<0.05 in all cases). Non-respiratory impairment and functional limitations were predictive of prospective disability, above-and-beyond sociodemographic characteristics, smoking status and respiratory impairment (area under the receiver operating characteristic curve increased from 0.65 to 0.75; p<0.001).Development of non-respiratory impairment and functional limitations, which reflect the systemic nature of COPD, appear to be critical determinants of disablement. Prevention and treatment of disability require a comprehensive approach to the COPD patient.
Project description:Investigation of whole genome gene expression level changes of the dynamic gene profiling of peripheral blood mononuclear cells (PBMCs) from patients with AECOPD) on day1, 3 and 10, compared to the normal people and stable COPD patients.
Project description:IntroductionPeople with COPD have a decline in functional status, but little is known about the rate of decline and factors that contribute. Of particular concern is the decline in cognitive and functional performance. Decrease in cognitive and functional performance will finally lead to decreased health status, sedentary life style and premature frailty.AimThe aim of this study is to compare functional performance and cognitive status in patients with COPD of different ages and to examine the changes in extrapulmonary effects.Patients and methodsThis study included 62 patients with COPD risk class D who were divided into two groups (<70 years, N=30 and >70 years, N=32). Patients first completed the Montreal Cognitive Assessment (MoCA), which is a 30-point test that assesses different cognitive domains, while isometric knee extension (IKE) was measured using a digital handheld dynamometer, and functional exercise level was assessed using the 6-minute walking distance (6MWD) test.ResultsThe patients' older age (age higher than 70 years) was associated with a significantly lower body mass index (BMI, 27.50 vs 24.24 kg/m2; P=0.020), higher vital capacity parameters, forced vital capacity (FVC, 2.74 vs 2.82 L; P=0.799), FVC (%) (73.00 vs 66.50, P=132), forced expiratory volume in the first second (FEV1, 0.93 vs 1.13 L; P=0.001) and FEV1 (%) (28.50 vs 30.50, P=0.605). In addition, patients at older age presented a significantly reduced physical activity capacity, 6MWD (385.93 vs 320.84 m, P<0.001) and IKE (24.75 vs 22.55 kgf, P=0.005), as well as higher values for inflammatory biomarkers, C-reactive protein (8.77 vs 3.34 mg/L, P=0.022). Moreover, patients at older age presented significantly lower score at the cognitive assessment, MoCA (23.50 vs 20.00, P<0.001).ConclusionElderly COPD patients have reduced exercise capacity and muscle strength, deteriorated cognitive function and increased inflammatory markers. Furthermore, inflammation markers were significantly correlated with muscle strength, walking distance and cognitive impairment.