Systemic Effects of Chronic Obstructive Pulmonary Disease

Abstract

Chronic obstructive pulmonary disease (COPD) is characterised by an inappropriate/excessive inflammatory response of the lungs to respiratory pollutants, mainly tobacco smoking.Recently, besides the typical pulmonary pathology of COPD (i.e. chronic bronchitis and emphysema), several effects occurring outside the lungs have been described, the socalled systemic effects of COPD. These effects are clinically relevant because they modify and can help in the classification and management of the disease.The present review discusses the following systemic effects of chronic obstructive pulmonary disease: 1) systemic inflammation; 2) nutritional abnormalities and weight loss; 3) skeletal muscle dysfunction; and 4) other potential systemic effects. For each of these, the potential mechanisms and clinical implications are discussed and areas requiring further research are highlighted.

Nutritional depletion and its relationship to respiratory impairment in patients with chronic respiratory failure due to COPD or restrictive thoracic diseases

“…Hypoxemia could well be relevant for nutritional status, as tissue hypoxemia per se can cause cellular energetic alterations, leading to an increased metabolic rate and reduced protein synthesis (Agusti et al, 2003). Moreover, in COPD, systemic inflammation is thought to show a causal relationship to nutritional depletion and is particularly prevalent in underweight patients (Gan et al, 2004).…”

“…In a previous comprehensive study of patients with chronic respiratory failure (CRF), the relationship between malnutrition and functional indices has been analysed while summarizing over different aetiologies, so that diseasespecific characteristics of the underlying mechanisms may have been obscured (Cano et al, 2002). Indeed, the majority of data on pulmonary cachexia refers to COPD and suggests a multifactorial nature of malnutrition (Congleton, 1999;Agusti et al, 2003). In COPD, lung hyperinflation seems to be one factor of interest as it results in a mechanical disadvantage, although the contribution of increased work of breathing to cachexia is not clear (Engelen et al, 1999;Mannix et al, 1999;Budweiser et al, 2005Budweiser et al, , 2006b).…”

Systemic manifestations and comorbidities of COPD

“…Patients with COPD, particularly when the disease is severe and during exacerbations, have evidence of systemic inflammation, measured either as increased circulating cytokines, chemokines and acute phase proteins, or as abnormalities in circulating cells [5][6][7]. Smoking itself may cause systemic inflammation, for example, and increased total leukocyte count, but in COPD patients the degree of systemic inflammation is greater.…”

Prevalence of COPD in Primary Care Clinics: Correlation with Non-Respiratory Diseases

“…(18,19), lung growth (20), gender (21,22), socioeconomic status (23) and nutrition (24). Furthermore, recently, it has been reported that systemic inflammation could be involved in the pathogenesis of COPD (5)(6)(7), and that COPD patients are at increased risk for several comorbidities including myocardial infarction, osteoporosis, depression and diabetes (1). However, it is still unclear whether such diseases affect the prevalence of COPD.…”

“…Recently, the high worldwide prevalence of COPD has been reported to be more than 9% in Europe (2), more than 11% in Latin America (3), and 8.6% in Japan (4). In addition, new aspects of COPD, such as systemic consequences and comorbidities, have received attention (5)(6)(7). It has been reported that up to 25% of the population older than 65 years suffers from two comorbid conditions and up to 17% have three (8).…”