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.