Chronic Obstructive Pulmonary Disease (COPD) and Malnutrition

COPD (chronic bronchitis, emphysema, asthma) is a chronic irreversible inflammatory disease that leads to a deterioration of the structure and function of the respiratory system, in relation to smoking and previous occupational exposures, with the natural history of the disease conditioning the exacerbations and respiratory failure that may occur.

The presence of malnutrition, especially in patients with emphysema, is a relevant prognostic factor that conditions possible acute complications in the form of flare-ups and the immunomodulatory capacity of response to stress. Similarly, the respiratory muscles (intercostal muscles and diaphragm) are affected over time, altering, together with metabolic disorders, the respiratory quotient progressively, increasing dyspnoea which, in the end, will greatly interfere with the patient's quality of life. Therefore, the presence of a low Body Mass Index (<21) or a fat-free mass index obtained by impedance measurement (<17 in men and 14 in women) has a great prognostic value, assessing the impact on exercise capacity with the walking test, being related to the number of exacerbations and mortality independent of the degree of respiratory obstruction.

The loss of lean mass due to the situation of maintained hypercatabolism, together with the different pathologies (cardiovascular, pulmonary hypertension) and medications present (diuretics can alter ions such as potassium or phosphates that increase muscular weakness, or magnesium that apart from weakness contributes to the maintenance of bronchial hyperreactivity), greatly alter the capacity for metabolic balance. In the nutritional recommendations to prevent the retention of CO2, it is postulated to reduce the intake of carbohydrates to 25-30% of nutritional requirements, increasing fats to 50%, and an adequate adjustment of proteins (1-1.2 gr/Kg) which if supplied in excess can contribute to hypercapnia, guaranteeing an energy supply based on basal needs and weighting it by a factor 1.2 in relation to the hypercatabolism produced.

In the previous recommendations for the management of chronic bronchitis, nutritional intervention was left in the background, as there was little evidence of its benefit. However, in these two recent studies* the effectiveness of enteral supplementation is analyzed in relevant variables such as strength of inspiratory and expiratory muscles, increases in fat-free mass, its relationship with quality of life and exercise tolerance. Although the degree of recommendation is not high (C level), there is beginning to be a field of evidence regarding relevant outcome variables, which makes nutritional assessment a priority target in the management of COPD patients, especially if they are elderly because of the functional impact it implies.

The holistic and comprehensive approach of a chronic pathology such as COPD in the elderly should be based on health education, assessing the appropriate management of different bronchodilators that symptomatically control the patient and avoid certain complications, as well as nutritional aspects and training programmes to prevent fragility. This approach allows the elderly to be kept in the best possible way in the appropriate resource, and in the case of Day Centres or Gerontology Centres it can represent a specific area of improvement by health teams, assessing exercise capacity, the level of dyspnoea, the number of flare-ups, rather than on obstructive parameters that depend on spirometric data which in those over 75 or with cognitive impairment are not valid.

"The true sign of intelligence is not knowledge, but imagination."
A. EINSTEIN

- Ferreira IM, Brooks D, White J et al. (2012) Nutritional supplementation for stable chronic obstructive pulmonary disease. Cochrane Database of Systematic Reviews issue 12: CD000998
- Collins PF, Elia M, Stratton RJ (2013) Nutritional support and functional capacity in chronic obstructive pulmonary disease: a systematic review and meta-analysis. Respirology 18: 616-29