The clinical validity of real-world walking cadence in people with COPD is unsettled. Our objective was to assess the levels, variability and association with clinically relevant COPD characteristics ...and outcomes of real-world walking cadence.
We assessed walking cadence (steps per minute during walking bouts longer than 10 s) from 7 days' accelerometer data in 593 individuals with COPD from five European countries, and clinical and functional characteristics from validated questionnaires and standardised tests. Severe exacerbations during a 12-month follow-up were recorded from patient reports and medical registries.
Participants were mostly male (80%) and had mean±sd age of 68±8 years, post-bronchodilator forced expiratory volume in 1 s (FEV
) of 57±19% predicted and walked 6880±3926 steps·day
. Mean walking cadence was 88±9 steps·min
, followed a normal distribution and was highly stable within-person (intraclass correlation coefficient 0.92, 95% CI 0.90-0.93). After adjusting for age, sex, height and number of walking bouts in fractional polynomial or linear regressions, walking cadence was positively associated with FEV
6-min walk distance, physical activity (steps·day
, time in moderate-to-vigorous physical activity, vector magnitude units, walking time, intensity during locomotion), physical activity experience and health-related quality of life and negatively associated with breathlessness and depression (all p<0.05). These associations remained after further adjustment for daily steps. In negative binomial regression adjusted for multiple confounders, walking cadence related to lower number of severe exacerbations during follow-up (incidence rate ratio 0.94 per step·min
, 95% CI 0.91-0.99, p=0.009).
Higher real-world walking cadence is associated with better COPD status and lower severe exacerbations risk, which makes it attractive as a future prognostic marker and clinical outcome.
INTRODUCTIONInterstitial lung disease (ILD) is associated with low exercise tolerance, dyspnea, and decreased health-related quality of life (HRQL). Idiopathic pulmonary fibrosis (IPF) is one of the ...most prevalent in the group. A specific version of the Saint George's questionnaire (SGRQ-I) has been developed to quantify the HRQL of IPF patients. However, this tool is not currently validated in the Spanish language. The objective was to translate into Spanish and validate the specific Saint George's Respiratory Questionnaire for idiopathic pulmonary fibrosis (SGRQ-I). METHODSThe repeatability, internal consistency and construct validity of the SGRQ-I in Spanish were analyzed after a backtranslation process. RESULTSIn total, 23 outpatients with IPF completed the translated SGRQ-I twice, 7 days apart. Repeatability was studied, revealing good concordance in test-retest with an ICC (interclass correlation coefficient) of 0.96 (P<.001). Internal consistency was good for different questionnaire items (Cronbach's alpha of 0.9 including and 0.81 excluding the total value) (P<.001). The total score of the questionnaire showed good correlation with forced vital capacity FVC% (r=-0.44; P=.033), diffusing capacity of the lungs for carbon monoxide (DLCO%) (r=-0.55; P=.011), partial pressure of oxygen in arterial blood PaO2 (r=-0.44; P=.036), Medical Research Council Dyspnea scale (r=-0.65; P<.001), and number of steps taken in 24hours (r=-0.47; P=.024). CONCLUSIONSThe Spanish version of SGRQ-Ideveloped by our group shows good internal consistency, reproducibility and validity, so it can be used for the evaluation of quality of life (QOL) in IPF patients.
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Although mean physical activity in COPD patients declines by 400–500steps/day annually, it is unknown whether the natural progression is the same for all patients. We aimed to ...identify distinct physical activity progression patterns using a hypothesis-free approach and to assess their determinants.
We pooled data from two cohorts (usual care arm of Urban Training NCT01897298 and PROactive initial validation NCT01388218 studies) measuring physical activity at baseline and 12 months (Dynaport MoveMonitor). We identified clusters (patterns) of physical activity progression (based on levels and changes of steps/day) using k-means, and compared baseline sociodemographic, interpersonal, environmental, clinical and psychological characteristics across patterns.
In 291 COPD patients (mean±SD 68±8 years, 81% male, FEV1 59±19%pred) we identified three distinct physical activity progression patterns: Inactive (n=173 59%, baseline: 4621±1757 steps/day, 12-month change (Δ): −487±1201 steps/day), ActiveImprovers (n=49 17%, baseline: 7727±3275 steps/day, Δ:+3378±2203 steps/day) and ActiveDecliners (n=69 24%, baseline: 11 267±3009 steps/day, Δ: −2217±2085 steps/day). After adjustment in a mixed multinomial logistic regression model using Active Decliners as reference pattern, a lower 6-min walking distance (RRR 95% CI 0.94 0.90–0.98 per 10m, P=.001) and a higher mMRC dyspnea score (1.71 1.12–2.60 per 1 point, P=.012) were independently related with being Inactive. No baseline variable was independently associated with being an Active Improver.
The natural progression in physical activity over time in COPD patients is heterogeneous. While Inactive patients relate to worse scores for clinical COPD characteristics, Active Improvers and Decliners cannot be predicted at baseline.
Aunque la actividad física en pacientes con EPOC declina una media anual de 400-500 pasos/día, se desconoce si esta progresión es igual en todos los pacientes. Este estudio pretendió identificar los patrones de progresión de la actividad física mediante métodos libres de hipótesis y evaluar sus determinantes.
Se estudiaron 291 pacientes con EPOC estable (media±DE: 68±8años, 81% hombres, VEMS 59±19%pred) de dos cohortes europeas con actividad física basal y a 12meses (acelerómetro Dynaport MoveMonitor). Se identificaron conglomerados (patrones) de progresión de actividad física basados en los niveles y cambios de pasos/día usando k-means, y se compararon entre patrones las características sociodemográficas, interpersonales, ambientales, clínicas y psicosociales basales.
Se identificaron tres patrones: inactivo (n=173 59%, basal: 4.621±1.757 pasos/día, cambio en 12meses (Δ): −487±1.201 pasos/día), activo que aumenta (n=49 17%, basal: 7.727±3.275 pasos/día, Δ: +3.378±2.203 pasos/día) y activo que reduce (n=69 24%, basal: 11.267±3.009 pasos/día, Δ: −2.217±2.085 pasos/día). La distancia en la prueba de la marcha de 6minutos (6MWD) y la disnea se asociaron independientemente con ser inactivo: RRR IC95% 0,94 0,90-0,98 por cada 10m de 6MWD (p=0,001) y 1,71 1,12-2,60 por cada punto en la escala mMRC (p=0,012), respectivamente, en comparación con el patrón activo que reduce. No se encontraron variables basales independientemente asociadas con ser activo que aumenta.
La progresión natural de la actividad física en pacientes con EPOC es heterogénea. Mientras que el patrón de pacientes inactivo se relaciona con peores características clínicas de EPOC, no se pudo predecir la evolución de los activos a aumentar o reducir.
Understanding the impacts of activity on energy balance is crucial. Increasing levels of activity may bring diminishing returns in energy expenditure because of compensatory responses in non-activity ...energy expenditures.1–3 This suggestion has profound implications for both the evolution of metabolism and human health. It implies that a long-term increase in activity does not directly translate into an increase in total energy expenditure (TEE) because other components of TEE may decrease in response—energy compensation. We used the largest dataset compiled on adult TEE and basal energy expenditure (BEE) (n = 1,754) of people living normal lives to find that energy compensation by a typical human averages 28% due to reduced BEE; this suggests that only 72% of the extra calories we burn from additional activity translates into extra calories burned that day. Moreover, the degree of energy compensation varied considerably between people of different body compositions. This association between compensation and adiposity could be due to among-individual differences in compensation: people who compensate more may be more likely to accumulate body fat. Alternatively, the process might occur within individuals: as we get fatter, our body might compensate more strongly for the calories burned during activity, making losing fat progressively more difficult. Determining the causality of the relationship between energy compensation and adiposity will be key to improving public health strategies regarding obesity.
•Energy compensation in humans was analyzed from daily and basal energy expenditure•Reduced BEE results in energy compensation of 28%•Degree of energy compensation varied between people of different body composition
Energy compensation is the concept that not all the energy spent when activity levels increase translates to additional energy spent that day, but it is poorly characterized. Careau, Halsey et al. find that in humans, energy compensation averages 28%, i.e., only 72% of the extra calories we spend on additional activity translates into extra calories burned that day.
Update in chronic obstructive pulmonary disease 2008 Maclay, John D; Rabinovich, Roberto A; MacNee, William
American journal of respiratory and critical care medicine,
2009-Apr-01, 2009-04-01, 20090401, Letnik:
179, Številka:
7
Journal Article
Resumen Introducción Las enfermedades pulmonares intersticiales (EPI) se asocian a una baja tolerancia al ejercicio, disnea y disminución de la calidad de vida relacionada con la salud (CVRS). La ...fibrosis pulmonar idiopática (FPI) es una de las más prevalentes del grupo. Para cuantificar su CVRS, se ha desarrollado una versión específica del cuestionario Saint George (SGRQ- I ). Sin embargo, esta herramienta no está actualmente validada en el idioma español. El objetivo fue traducir al idioma español y validar el SGRQ- I en pacientes con FPI. Métodos Se estudiaron la repetibilidad, la consistencia interna y la validez de constructo del SGRQ- I en español obtenido luego del proceso de traducción reversa. Resultados Veintitrés pacientes con FPI completaron 2 veces el cuestionario traducido con 7 días de diferencia cada uno. Encontramos una buena concordancia en el test-retest, con un coeficiente de correlación intraclase (CCI) de 0,96 (p < 0,001). En el estudio de la consistencia interna hallamos un coeficiente alfa de Cronbach de 0,9 al incluir al valor total, y de 0,81 al excluirlo (p < 0,001), lo cual evidencia una buena interrelación de los diferentes ítems del cuestionario. El valor total del cuestionario mostro buena correlación con FVC% (r = –0,44; p = 0,033), DLCO % (r = –0,55; p = 0,011), PaO2 (r = –0,44; p = 0,036), disnea escala modificada de Medical Research Council (r = –0,65; p < 0,001), y pasos dados en 24 h (r = –0,47; p = 0,024). Conclusión La versión en español del SGRQ- I desarrollada por nuestro grupo tiene buena consistencia interna, es reproducible y es válida para evaluar calidad de vida en pacientes con FPI.
Water is essential for survival, but one in three individuals worldwide (2.2 billion people) lacks access to safe drinking water. Water intake requirements largely reflect water turnover (WT), the ...water used by the body each day. We investigated the determinants of human WT in 5604 people from the ages of 8 days to 96 years from 23 countries using isotope-tracking (
H) methods. Age, body size, and composition were significantly associated with WT, as were physical activity, athletic status, pregnancy, socioeconomic status, and environmental characteristics (latitude, altitude, air temperature, and humidity). People who lived in countries with a low human development index (HDI) had higher WT than people in high-HDI countries. On the basis of this extensive dataset, we provide equations to predict human WT in relation to anthropometric, economic, and environmental factors.
Systemic consequences and associated comorbidities are highly prevalent in patients with chronic obstructive pulmonary disease and have a strong impact on morbidity and mortality. This review ...examines their prevalence and clinical features, and discusses the pathogenic mechanisms, prognosis and implications for therapy.
The present study was undertaken to test whether endurance training in patients with COPD, along with enhancement of muscle bioenergetics, decreases muscle redox capacity as a result of recurrent ...episodes of cell hypoxia induced by high intensity exercise sessions. Seventeen patients with COPD (FEV(1), 38 +/- 4% pred; PaO2), 69 +/- 2.7 mm Hg; PaCO2, 42 +/- 1.7 mm Hg) and five age-matched control subjects (C) were studied pretraining and post-training. Reduced (GSH) and oxidized (GSSG) glutathione, lipid peroxidation, and gamma-glutamyl cysteine synthase heavy subunit chain mRNA expression (gammaGCS-HS mRNA) were measured in the vastus lateralis. Pretraining redox status at rest and after moderate (40% Wpeak) constant-work rate exercise were similar between groups. After training (DeltaWpeak, 27 +/- 7% and 37 +/- 18%, COPD and C, respectively) (p < 0.05 each), GSSG levels increased only in patients with COPD (from 0.7 +/- 0.08 to 1.0 +/- 0.15 nmol/ mg protein, p < 0.05) with maintenance of GSH levels, whereas GSH markedly increased in C (from 4.6 +/- 1.03 to 8.7 +/- 0.41 nmol/ mg protein, p < 0.01). Post-training gammaGCS-HS mRNA levels increased after submaximal exercise in patients with COPD. No evidence of lipid peroxidation was observed. We conclude that although endurance training increased muscle redox potential in healthy subjects, patients with COPD showed a reduced ability to adapt to endurance training reflected in lower capacity to synthesize GSH.
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