Physical activity patterns and clusters in 1001 patients with COPD.

We described physical activity measures and hourly patterns in patients with chronic obstructive pulmonary disease (COPD) after stratification for generic and COPD-specific characteristics and, based on multiple physical activity measures, we identified clusters of patients. In total, 1001 patients with COPD (65% men; age, 67 years; forced expiratory volume in the first second [FEV], 49% predicted) were studied cross-sectionally. Demographics, anthropometrics, lung function and clinical data were assessed.

Analysis of nocturnal actigraphic sleep measures in patients with COPD and their association with daytime physical activity.

Background: Sleep disturbances are common in patients with chronic obstructive pulmonary disease (COPD) with a considerable negative impact on their quality of life. However, factors associated with measures of sleep in daily life have not been investigated before nor has the association between sleep and the ability to engage in physical activity on a day-to-day basis been studied.

Aims: To provide insight into the relationship between actigraphic sleep measures and disease severity, exertional dyspnoea, gender and parts of the week; and to investigate the association between sleep measures and next day physical activity.

Oxygen Uptake Recovery Kinetics after the 6-Minute Walk Test in Patients with Chronic Obstructive Pulmonary Disease.

Background: There is a growing interest in exercise parameters capable of objectively evaluating the functional capacity of patients with chronic obstructive pulmonary disease (COPD).

Objectives: The purpose of the present study was to analyze breath-by-breath cardiopulmonary and gas exchange recovery responses of patients with COPD after a 6-minute walk test (6MWT).

Methods: Oxygen uptake (VO2) kinetics of patients were obtained using mobile telemetric cardiopulmonary monitoring during and after a 6MWT.

Modeling the oxygen uptake kinetics during exercise testing of patients with chronic obstructive pulmonary diseases using nonlinear mixed models.

Background: The six-minute walk test (6MWT) is commonly used to quantify exercise capacity in patients with several cardio-pulmonary diseases. Oxygen uptake ([Formula: see text]O2) kinetics during 6MWT typically follow 3 distinct phases (rest, exercise, recovery) that can be modeled by nonlinear regression. Simultaneous modeling of multiple kinetics requires nonlinear mixed models methodology.

Identifying Physical Activity Profiles in COPD Patients Using Topic Models.

With the growing amount of physical activity (PA) measures, the need for methods and algorithms that automatically analyze and interpret unannotated data increases. In this paper, PA is seen as a combination of multimodal constructs that can cooccur in different ways and proportions during the day. The design of a methodology able to integrate and analyze them is discussed, and its operation is illustrated by applying it to a dataset comprising data from COPD patients and healthy subjects acquired in daily life.

Cardiopulmonary and gas-exchange responses during the six-minute walk test in patients with chronic obstructive pulmonary disease.

Background: The 6-min walk test (6MWT) is representative of daily life activities and reflects the functional capacity of patients with chronic obstructive pulmonary disease (COPD). Information on the cardiopulmonary and gas exchange responses to the 6MWT is limited.

Objectives: We aimed to analyze the breath-by-breath cardiopulmonary and gas exchange responses of patients with COPD during the 6MWT.

Association between peripheral muscle strength, exercise performance, and physical activity in daily life in patients with Chronic Obstructive Pulmonary Disease.

Background: Resistance training of peripheral muscles has been recommended in order to increase muscle strength in patients with Chronic Obstructive Pulmonary Disease (COPD). However, whether peripheral muscle strength is associated with exercise performance (EP) and physical activity in daily life (PADL) in these patients needs to be investigated. The aim of this study is to evaluate whether strength of the quadriceps muscle (QS) is associated with EP and daily PADL in patients with COPD.

High prevalence of altered cardiac repolarization in patients with COPD.

Background: Altered cardiac repolarization and increased dispersion of repolarization have been identified as risk factors for sudden cardiac death (SCD). The prevalence of and the mechanisms contributing to altered cardiac repolarization are currently unknown in COPD.

Methods: In 91 COPD patients, 32 controls matched for age, cardiovascular risk and medication, and 41 healthy subjects, measures of cardiac repolarization and dispersion of repolarization (QTc interval, QT dispersion) were derived from 12-lead electrocardiography (ECG).

Association between peripheral muscle strength and daily physical activity in patients with COPD: a systematic literature review and meta-analysis.

Background: Patients with chronic obstructive pulmonary disease have skeletal muscle dysfunction and reduced daily physical activity (PA). Whether the reduction in quadriceps strength (QS) is directly linked to physical inactivity remains to be elucidated.

Methods: A systematic review and a meta-analysis were conducted to determine the potential relationship between QS and the level of PA.

The speed of blood pressure fluctuations in patients with chronic obstructive pulmonary disease.

Background: Chronic obstructive pulmonary disease (COPD) has been associated with increased risk for cardiovascular disease but mechanisms underlying this association are incompletely understood. The speed of beat-to-beat changes in systolic blood pressure (vSBP) was found to be pronounced in patients with elevated cardiovascular risk. Although increased vSBP may thus be a contributing mechanism to cardiovascular morbidity, no data exist on vSBP in patients with COPD.

Quantifying the speed of fluctuations in systolic blood pressure.

Increased blood pressure variability (BPV), even in the absence of hypertension, has been identified as an important independent cardiovascular risk factor (CVRF). However, the role of the speed of changes in systolic blood pressure (SBP; vSBP) on cardiovascular risk needs to be investigated. The objective of this study was to investigate whether subjects with a high cardiovascular risk profile have an increased degree and speed of changes in SBP compared with subjects with low or no risk.

Determinants of endothelial function in patients with COPD.

Chronic obstructive pulmonary disease (COPD) is associated with increased cardiovascular mortality. Endothelial dysfunction may underpin this association. This cross-sectional study aimed to determine the impact of airflow obstruction, systemic inflammation, oxidative stress, sympathetic activation, hypoxaemia and physical activity on endothelial function in COPD.

Sympathetic overactivity and cardiovascular disease in patients with chronic obstructive pulmonary disease (COPD).

Cardiovascular disease plays an important role regarding the morbidity and mortality in patients with chronic obstructive pulmonary disease (COPD). Sympathetic overactivity has been suggested to underpin the association between COPD and the development of cardiovascular disease. However, the pathophysiological basis by which sustained sympathetic overactivity affects cardiovascular function in patients with COPD is complex and incompletely understood.

Predicting daily physical activity in patients with chronic obstructive pulmonary disease.

Background: Objectively measuring daily physical activity (PA) using an accelerometer is a relatively expensive and time-consuming undertaking. In routine clinical practice it would be useful to estimate PA in patients with chronic obstructive pulmonary disease (COPD) with more simple methods.

Objectives: To evaluate whether PA can be estimated by simple tests commonly used in clinical practice in patients with COPD.

Cardiac autonomic function and cardiovascular response to exercise in patients with chronic obstructive pulmonary disease.

Background: Chronic obstructive pulmonary disease (COPD) is associated with impaired exercise tolerance, but it has not been established to what extent cardiac autonomic function impacts on exercise capacity.

Objective: To evaluate whether there is an association between airflow limitation and cardiac autonomic function and whether cardiac autonomic function plays a role in exercise intolerance and daily physical activity (PA) in patients with COPD.

Methods: Univariate and multivariate analyses were performed to evaluate the association between both 6-minute walking test (6MWT) and PA (steps per day) and pulmonary function, cardiac autonomic function (HR at rest, HRR and heart rate variability, HRV) in patients with COPD.

Autonomic dysfunction in patients with chronic obstructive pulmonary disease (COPD).

It has been recognized that chronic obstructive pulmonary disease (COPD) is a systemic disease which has been shown to negatively affect the cardiovascular and autonomic nerve system. The complexity of the physiologic basis by which autonomic dysfunction occurs in patients with COPD is considerable and the knowledge in this field remains elementary. The purpose of this review is to provide an overview of important potential mechanisms which might affect the autonomic nervous system in patients with COPD.

Comparison of photoplethysmographic and arterial tonometry-derived indices of arterial stiffness.

Arterial tonometry is a method to assess arterial stiffness and has become a valuable tool in the stratification of cardiovascular risk. The arterial tonometry-derived augmentation index (AIx) is a marker of arterial stiffness and an independent predictor of mortality. As the AIx is relatively cumbersome to obtain, simpler methods such as analysis of pulse waves obtained by digital photoplethysmography have been proposed to estimate arterial stiffness.

Cardiac autonomic dysfunction and health-related quality of life in patients with chronic obstructive pulmonary disease.

Background And Objective: COPD is associated with impaired health-related quality of life (HRQL) and cardiac autonomic dysfunction. Data describing the association between these factors in patients with COPD are mostly lacking. The objective of this study was to evaluate whether there is an association between cardiac autonomic dysfunction and HRQL in COPD.

The effects of controlled breathing during pulmonary rehabilitation in patients with COPD.

Background: Conventional pulmonary rehabilitation programs improve exercise tolerance but have no effect on pulmonary function in patients with chronic obstructive pulmonary disease (COPD). The role of controlled breathing using respiratory biofeedback during rehabilitation of patients with COPD remains unclear.

Objectives: To compare the effects of a conventional 4-week pulmonary rehabilitation program with those of rehabilitation plus controlled breathing interventions.