Nutritional intervention in COPD: a systematic overview.

OBJECTIVE: We conducted a systematic overview of randomized controlled trials (RCTs) to clarify the contribution of nutritional supplementation for patients with stable COPD. METHODS: RCTs were identified from several sources, including the Cochrane Airways Group register of RCTs, a hand search of abstracts presented at international meetings, and consultation with experts. Two reviewers independently selected trials for inclusion, assessed quality, and extracted the data. RESULTS: Twenty-one reports were classified according to the type, duration of supplementation, and the presence of anabolic substances. High carbohydrate meals were associated with an increase in carbon dioxide production and a decrease in exercise capacity. Short-term crossover studies in which diets of various compositions were administered supported the notion that high carbohydrate loads increase the stress on the ventilatory system. The influence of longer-term supplementation (> 2 weeks) on weight, anthropometry, and exercise capacity varied, without there being a consistent effect. Lean body weight was only occasionally reported and health-related quality of life too rarely to be included as an outcome. The influence of recombinant human growth hormone was disappointing. Anabolic steroids increased body weight and lean body mass, but had little influence on exercise capacity. CONCLUSION: This systematic overview in patients with COPD supports the notion that those with marginal ventilatory reserve might benefit from a dietary regimen in which a high percentage of calories are supplied by fat. Although there are reports of the benefits of nutritional repletion, trials of > 2 weeks failed to show consistent benefit on body weight. Evaluating nutritional repletion is hampered by the absence of information regarding body composition, exercise, and health-related quality of life. Growth hormone has not been shown to be useful. Further studies are needed to refine the beneficial effects of anabolic steroids as adjunctive agents together with nutritional support and exercise.

Nutrition in chronic obstructive pulmonary disease.

Weight loss is a frequently occurring complication in patients with chronic obstructive pulmonary disease (COPD) and is a determining factor of functional capacity, health status, and mortality. Weight loss in COPD is a consequence of increased energy requirements unbalanced by dietary intake. Both metabolic and mechanical inefficiency contribute to the elevated energy expenditure. A disbalance between protein synthesis and protein breakdown may cause a disproportionate depletion of fat-free mass in some patients. Nutritional support is indicated for depleted patients with COPD because it provides not only supportive care, but direct intervention through improvement in respiratory and peripheral skeletal muscle function and in exercise performance. A combination of oral nutritional supplements and exercise or anabolic stimulus appears to be the best treatment approach to obtaining significant functional improvement. Patients responding to this treatment even demonstrated a decreased mortality. Poor response was related to the effects of systemic inflammation on dietary intake and catabolism. The effectiveness of anticatabolic modulation requires further investigation.

Nutritional support for individuals with COPD: a meta-analysis.

RATIONALE: Malnutrition in patients with COPD is associated with an impaired pulmonary status, reduced diaphragmatic mass, lower exercise capacity, and higher mortality rate when compared to adequately nourished individuals with COPD. Nutritional support may therefore be a useful part of their comprehensive care. PURPOSE: To conduct a meta-analysis of randomized controlled trials (RCTs) to clarify whether nutritional supplementation (caloric supplementation for at least 2 weeks) improved anthropometric measures, pulmonary function, respiratory muscle strength, and functional exercise capacity in patients with stable COPD. METHODS: RCTs were identified from several sources, including the Cochrane Airways Group register of RCTs, a hand search of abstracts presented at international meetings, and consultation with experts. Two reviewers independently selected trials for inclusion, assessed quality, and extracted the data. Within each trial and for each outcome, we calculated an effect size. The effect sizes were then pooled by a random-effects model. Homogeneity among the effect sizes was also tested. RESULTS: From 272 references, nine RCTs were ultimately included. Six articles were considered as high quality. Only two studies were double blinded. For each of the outcomes studied, the effect of nutritional support was small: the 95% confidence intervals around the pooled effect sizes all included zero. The effect of nutritional support was homogeneous across studies. CONCLUSION: Nutritional support had no effect on improving anthropometric measures, lung function, or functional exercise capacity among patients with stable COPD.

Characterization of nonresponse to high caloric oral nutritional therapy in depleted patients with chronic obstructive pulmonary disease.

Nutritional support can increase body weight and physiologic function in COPD, but there are some patients who do not respond to nutritional therapy. The aim of this prospective study was to describe the nonresponse to 8 wk of oral nutritional supplementation therapy (500 to 750 kcal/d extra), implemented in an inpatient pulmonary rehabilitation program, with respect to lung function, body composition, energy balance, and systemic inflammatory profile in 24 (16 male) depleted patients with COPD. On the basis of the weight change after 8 wk, patients were divided into three groups (Group 1: weight gain < 2% of baseline body weight, n = 5; Group 2: weight gain 2 to 5%, n = 9; Group 3: weight gain >/= 5%, n = 10). Although no differences were seen in lung function and body composition, Group 1 was characterized by older age, a lower baseline dietary intake/resting energy expenditure (REE) ratio, and a greater number of users of continuous supplemental oxygen when compared with Group 3. In addition, Group 1 exhibited higher baseline concentrations of fasting glucose and LPS-binding protein than did Groups 2 and 3. The concentrations of the soluble TNF- receptors 55 and 75 were elevated in Groups 1 and 2 when compared with Group 3. Furthermore, a significant, inverse correlation coefficient between baseline dietary intake and soluble intercellular adhesion molecule was revealed (r = -0.50, p = 0.016). On linear regression analysis, age, baseline intake/REE ratio, sTNF-receptor 55, and extracellular/intracellular water (ECW/ICW) ratio were selected as independent, significant parameters contributing to a total explained variation of 78% in weight change after nutritional therapy. In conclusion, nonresponse to nutritional therapy in COPD is associated with ageing, relative anorexia, and an elevated systemic inflammatory response. Further research is needed to investigate whether these factors contribute to eventual disturbances in intermediary metabolism as reflected by the increased glucose concentration and ECW/ICW ratio.

Role of polyunsaturated fatty acids in lung disease.

DF Horrobin hypothesized that the low prevalence of lung disease among Eskimos is the result of their diet, which is high in n-3 fatty acids. The n-3 and n-6 fatty acids shunt eicosanoid production away from the arachidonic acid pathway, and hence decrease the production of bronchoconstrictive leukotrienes. Animal studies showed that eicosapentaenoic acid or gamma-linolenic acid supplementation of animals exposed to endotoxins results in decreased effects on thromboxane B(2) and pulmonary vascular resistance. Small human trials confirmed that supplementation with eicosapentaenoic acid results in increased eicosapentaenoic acid in phospholipids and decreased generation of leukotrienes by neutrophils. Hence, a protective effect of such fatty acids in lung disease is biologically plausible. The results of human intervention studies looking at respiratory outcomes have been mixed, but they do suggest a possible difference between long-term and short-term effects. Epidemiologic studies showed possible protective effects against asthma in children, but weak to no evidence of such effects in adults. Results for bronchitis are more positive, although intervention trials are lacking. Recently, a cross-sectional analysis of data from the first National Health and Nutrition Examination Survey reported an approximately 80-mL difference in forced expiratory volume at 1 s between adults with high compared with low fish consumption. This response was not limited to asthmatic subjects. Others found that both fish consumption and n-3 fatty acid consumption (as estimated from food-frequency questionnaires) were protective against physician-diagnosed emphysema and chronic bronchitis and low spirometry values. Only smokers were included in this analysis. These results suggest that dietary fatty acids may play a role in lung disease; further work is needed to elucidate that role.

Nutritional abnormalities and supplementation in chronic obstructive pulmonary disease.

Weight loss and muscle wasting commonly occur in patients with chronic obstructive pulmonary disease (COPD). A decreased dietary intake and elevated energy requirements underlie weight loss in these patients. Disturbances in intermediary metabolism caused by altered anabolic and catabolic mediators such as hormones, cytokines, and growth factors, and resulting in disproportionate muscle wasting have been described. Nutritional supplementation in combination with an anabolic stimulus (e.g. exercise) has been shown effective in improving functional capacity, health status, and mortality in most depleted patients. Nutritional or pharmacologic modulation of the catabolic response may further enhance the response in the near future.

[Oral nutritional supplements. Are they useful?]. / Suplementos nutricionales orales. Son útiles?

Oral nutritional supplements are products included in enteral nutrition, preferably used in hospital settings, although their use in the community is gradually increasing and in the United Kingdom has doubled in the last seven years, with prescriptions covering a wide range of the population from children to the elderly, and different pathologies affecting their nutritional status. There is, however, no consensus on the usefulness of oral nutritional supplements among these patients, so we do not have any recommendations for use. In this paper we have reviewed the various studies available in the literature in order to clarify the usefulness of these supplements in different contexts or pathologies.

Monitoraçäo nutricional de pacientes com doença pulmonar obstrutiva crônica do programa de reabilitaçäo pulmonar / Nutritional monitoring of patients with chronic obstructive pulmonary disease from pulmonary rehabilitation program

Uma equipe multidisciplinar do Hospital das Clínicas da Universidade Federal de Goiás (HC-UFG) iniciou um trabalho de reabilitaçäo pulmonar de pacientes com Doença Pulmonar Obstrutiva Crônica (DPOC). As nutricionistas envolvidas avaliaram e monitoraram nutricionalmente estes pacientes e analisaram a adequaçäo da ingestäo dietética, bem como as relações entre os parâmetros da funçäo pulmonar e o estado nutricional. Participaram do estudo, 19 pacientes, sendo 4 do sexo feminino e 15 do masculino. O estado nutricional foi avaliado no início do programa e, posteriormente, ao final de 3 meses por meio de parâmetros antropométricos, bioquímicos, hematológicos e de ingestäo alimentar. Também foram realizadas espirometria e gasometria para se determinar a funçäo pulmonar. Observou-se que 78,94 por cento dos pacientes apresentaram déficit de peso de 15,60 ñ 10,08 por cento e que os índices antropométricos, bioquímicos e hematológicos näo diferiram estatisticamente ao final do estudo, assim como os resultados dos testes de funçäo pulmonar.

COPD: using nutrition to prevent respiratory function decline.

Close to three-fourths of patients with chronic obstructive pulmonary disease (COPD) suffer from weight loss. Identifying a single cause for this is difficult, as several factors-including chronic mouth breathing, dyspnea, aerophagia, certain medications, and depression-often act in concert. Malnutrition can exacerbate symptoms of COPD by decreasing ventilatory muscle strength, exercise tolerance, and immunocompetence, and by increasing the risk of depression and anxiety. Goals of nutrition intervention are to prevent or reverse malnutrition without worsening the disease process and to improve respiratory function, thereby reducing morbidity and delaying mortality. Recommendations for intake of fats, carbohydrates, protein, and water must be individualized.

[Fat-rich diets in patients with mild chronic obstructive lung disease (COPD)]. / Dietas ricas en grasa en pacientes con enfermedad pulmonar obstructiva crónica (EPOC) leve.

A study was made in stable patients suffering from mild COLD of the maximum capacity for ergometric cycle exercise and gas exchange at rest and during maximum exercise, measured by indirect calorimetry. During the period of study (3 months) one group of patients receive the usual diet while the other received an oral nutritional supplement rich in fats an minimum of 75% of their energy expenditure measured at rest. The patients studied, with mild COLD, were hypermetabolic, and although at rest they presented indirect calorimetry data such as would correspond to similar subjects, during exercise not just the limit on exercise became clear but also the alteration to ventilatory capacity and gas exchange. The fat-rich nutritional supplement administered for three months did not succeed in enhancing exercise capacity or in altering gas exchange during maximum exercise is stable patients with mild COLD.