Prevalence of malnutrition in outpatients with stable chronic obstructive pulmonary disease

OBJECTIVE: To determine the prevalence of malnutrition in outpatients with stable chronic obstructive pulmonary disease (COPD) followed at a respiratory clinic. MATERIAL AND METHOD: In this prospective study, we assessed the nutritional status of consecutive outpatients with stable COPD by investigating various anthropometric parameters. Patients were malnourished (low body weight) if their body mass index was within the bottom quartile of a reference population. Muscle mass was determined from the midarm muscle area and if this mass was at or within the bottom quartile, muscle wasting was present. Albumin and transferrin plasma concentrations were used as a measure of visceral protein stores. Fat stores were assessed from body fat and if this value was at or within the bottom quartile, calorific malnutrition was present. All patients underwent arterial blood gas sampling at rest and spirometry. RESULTS: A total of 178 patients-one woman (0.6%) and 177 men (99.4%)-were enrolled in the study, with a mean (SD) age of 69 (9) years. We found low body weight in 19.1% of the patients, muscle wasting in 47.2%, visceral protein depletion in 17.4%, and fat depletion in 19.1%. Of the patients with normal weight, 62.9% showed muscle wasting. The proportion of patients with a body mass index or midarm muscle area at or within the bottom quartile increased significantly with increased bronchial obstruction (P < .001 and P = .015, respectively), though 35.7% of the patients showed muscle wasting even when COPD was mild. CONCLUSIONS: Many patients with stable COPD suffer malnutrition. Nutritional state is worse with more severe COPD. Depletion involves both fat stores and muscle and visceral protein stores, but the greatest effect is seen in muscle wasting. A significant number of patients with normal weight also suffer muscle wasting. Although changes in body composition were common in our patients, low body weight was less prevalent than has been reported for populations in countries that are socially and economically similar to Spain.