Nutritional supplementation in ambulatory patients with chronic obstructive pulmonary disease.

We examined the effect of nutritional supplementation for 8 wk on respiratory muscle function (RMF) in 21 malnourished patients with COPD. Patients were randomized to a fed group or to a control group. Patients in the fed group were provided with an enteral formula in addition to their usual diet. Daily calorie and protein intake and weekly anthropometric measures were made. Pulmonary function tests were measured on Weeks 1, 4, and 8. Respiratory muscle strength was measured by means of maximal inspiratory and expiratory pressures (MIP), (MEP), and respiratory muscle endurance was measured by the maximal sustained ventilatory capacity (MSVC). The mean weight of the fed group increased from 52.2 +/- 6.4 to 53.3 +/- 6.9 kg (NS). The mean daily caloric intake of the fed group was significantly increased during the study (p less than 0.02). The mean calorie intake during the study of the fed group was 174 +/- 17% of the estimated basal energy expenditure. During the study period, no change was observed in anthropometric measures, pulmonary function studies, or RMF. Because patients tend to decrease their own food intake while receiving enteral formulas, it is difficult to provide sufficient calories and protein needed to effect changes in nutritional status and RMF in an outpatient COPD population. In addition, we compared RMF in 12 poorly nourished male patients (87.6 +/- 6.1% of ideal body weight) and 13 well-nourished male patients with severe COPD. Both groups had comparable degrees of air-flow limitation and hyperinflation. No difference was noted between the groups in either MIP, MEP, or MSVC.(ABSTRACT TRUNCATED AT 250 WORDS)