The relation between vitamin A status and the degree of lung airway obstruction was examined in a cross-sectional study of 36 male subjects aged 43-74 y who were assigned to five groups as follows: healthy nonsmokers (n = 7), healthy smokers (n = 7), mild chronic obstructive pulmonary disease (COPD-mild) patients (n = 9), COPD-moderate-severe patients (n = 7), and COPD-moderate-severe patients with exacerbation (+ex; n = 6). Smoking habits, pulmonary function tests, energy-protein status were assessed; serum concentrations of retinyl esters, retinol, retinol binding protein, and transthyretin and relative dose responses were measured. In addition, 12 male smokers aged 45-61 y with mild COPD were randomly assigned to two groups for a longitudinal study: six subjects consumed vitamin A (1000 RE/d; COPD-vitamin A) and six subjects received placebo for 30 d. Lowered serum retinol concentrations were found in the COPD-moderate-severe and COPD-moderate-severe+ex groups. Measurements of vitamin A status in healthy smokers and in COPD-mild patients were not different from those in healthy nonsmokers. The improvement of pulmonary function test results after vitamin A supplementation [mean increase for 1-s forced expiratory volume (FEV1) = 22.9% in the COPD-vitamin A group] may support the assumption of a local (respiratory) vitamin A deficiency in patients with this disease.

Tumour necrosis factor (TNF)-a has been found to be increased in malnourished chronic obstructive pulmonary disease (COPD) patients; however, the main cause of this phenomenon remains undetermined. In normal subjects, TNF-a production may be induced by dietary energy deprivation. The aim of this study was to investigate if stable COPD patients present alterations of inflammatory mediators after 48 h of dietary energy restriction.Fourteen COPD patients were admitted to the hospital while receiving an experimental diet with an energy content of approximately one-third of their energy needs. Clinical evaluation, nutritional assessment and serum levels of interleukin (IL)-6, TNF-a and C-reactive protein, and secretion of TNF-a by peripheral blood monocytes were assessed on admission and after the experimental diet. For reference values of the laboratory parameters, blood was collected from 10 healthy, elderly subjects.COPD patients showed significantly higher serum concentrations of IL-6 than control subjects, however, the experimental diet was not associated with statistically significant changes in the inflammatory mediators.The findings of this study, although preliminary because of the limited degree and duration of the energy restriction, suggest that the elevated levels of tumour necrosis factor-a, previously described in undernourished or weight-losing chronic obstructive pulmonary disease patients, may not be linked to a decrease of dietary energy intake. Eur Respir J 2003; 22: 920-925.

O presente estudo teve como objetivo o registro e a apresentação de trabalhos realizados no Brasil nos últimos 40 anos, relacionados com a investigação sobre a deficiência de vitamina A. Esta deficiência tem sido diagnosticada por um ou mais dos seguintes critérios: ingestão deficiente de alimentos fontes de vitamina A, exame clínico, níveis séricos de retinol abaixo dos aceitos como normais, concentração hepática de retinol, teste de adaptação ao escuro e corante de Rosa Bengala. A deficiência foi diagnosticada em grupos populacionais de vários Estados e capitais brasileiras em cidades grandes e pequenas e em zonas rurais. A maioria dos trabalhos foi desenvolvida em grupos populacionais de baixa renda. Quanto às conseqüências clínicas, relataram-se achados de sinais oculares leves, como cegueira noturna, manchas de Bitot e xerose conjuntival, encontrados principalmente na Região Nordeste. Alguns autores observaram, em menor número de casos, lesões graves, como lesões corneanas e ceratomalácia. Trabalhos da última década indicaram associação entre a hipovitaminose A e o aumento da morbidade e mortalidade, principalmente em crianças pré-escolares.