Nutritional Aspects of Chronic Obstructive Pulmonary Disease

Abstract

It is clear that being underweight is a poor prognostic sign in chronic obstructive pulmonary disease (COPD). It is also clear that undernutrition is at least in part associated with the severity of airflow obstruction. While both weight and body mass index are useful screening tools in the initial nutritional evaluation, fat-free mass (FFM) may be a better marker of undernutrition in patients with COPD. The causes of cachexia in patients with COPD are multifactorial and include decreased oral intake, the effect of increased work of breathing due to abnormal respiratory mechanics, and the effect of chronic systemic inflammation. Active nutritional supplementation in undernourished patients with COPD can lead to weight gain and improvements in respiratory muscle function and exercise performance. However, long-term effects of nutritional supplementation are not clear. In addition, the optimal type of nutritional supplementation needs to be explored further. The role of novel forms of treatment, such as androgens or appetite stimulants designed to increase FFM, also needs to be further studied. Thus, in the absence of definitive data, it cannot be said that long-term weight gain, either using enhanced caloric intake, with or without anabolic steroids or appetite stimulants, offers survival or other benefits to patients with COPD. However, there are indications from singlecenter trials that this is an avenue well worth exploring.

Ageing and COPD affect different domains of nutritional status: the ECCE study

“…In COPD patients, both physical inactivity due to exercise intolerance [29] and systemic inflammation [3] may explain the prevalent loss of fat-free mass. In addition, the expansion of extracellular and intracellular water volumes, driven by hypoxaemia, may explain why malnutrition may occur despite normal weight [30].…”

“…Amongst these, malnutrition is very common and its prevalence increases along with the severity of the disease [3,4]. Malnutrition has been recognised as a risk factor for mortality [5].…”

An Official American Thoracic Society/European Respiratory Society Statement: Update on Limb Muscle Dysfunction in Chronic Obstructive Pulmonary Disease

“…Impaired energy balance, due to elevated energy requirements, reduced dietary intake, or both, may lead to limb muscle atrophy (380,381). The energy balance may be compromised in COPD due to the complex interaction of a number of factors, including anorexia, elevated whole-body energy requirements, imbalance between muscle protein synthesis and breakdown, enhanced lipolysis, and an increase in pulmonary and systemic inflammatory mediators (382). Impairment in energy balance and protein balance may occur simultaneously, but these processes can also be dissociated, as reflected in the different COPD body composition phenotypes.…”

Healthy lifestyle interventions in general practice

“…10,13,27 It has been shown that, in these patients, weight loss and muscle wasting are associated with an increased risk of acute exacerbations, hospital admissions, and the need for mechanical ventilation. 10 It has been observed that muscle wasting and weight loss affects about 33% of patients with chronic respiratory disease.…”