Chronic obstructive pulmonary disease and malnutrition: why are we not winning this battle?

RESUMO

OBJECTIVES: To review the mechanisms involved in the origin of malnutrition in patients with chronic obstructive pulmonary disease (COPD), and to make a systematic review of randomized controlled studies, to clarify the contribution of nutritional supplementation in patients with stable COPD. METHOD: A systematic review of articles published in the field of nutrition, in any language and from several sources, including Medline, Embase, Cinahl, and the Cochrane Registry on COPD, as well as studies presented at congresses in the US and Europe. RESULTS: Studies on nutritional supplementation for more than two weeks showed a very small effect, not reaching statistical significance. A linear regression study found that old age, relative anorexia, and high inflammatory response are associated with non-response to nutritional therapy. CONCLUSION: Currently, there is no evidence that nutritional supplementation is truly effective in patients with COPD. Factors associated with non-response suggest a relationship with the degree of inflammation, including high TNF-alpha levels. Measuring inflammation markers may be useful to determine prognosis and adequate therapy. Treatment with anti-inflammatory cytokines or cytokine inhibitors seems promising for the future.