Effect of Nutrition on Inspiratory Muscles and FEV1 in Patients with Emphysema

Malnutrition is an effective factor in respiratory muscles dysfunction in patients with chronic obstructive pulmonary disease (COPD). The present study was performed to evaluate the effect of improved nutrition on inspiratory muscles in patients with advanced COPD. Total of 33 patients suffering from emphysema were studied during a 3-year period using a quasi experimental (before- after study) method. All of them had forced expiratory volume in one second (FEV1) <30% and had received Atrovent, Salmeterol, Becotide (in maximum doses) and oxygen therapy for at least one year. Initially, FEV1 and airways resistance of patients were measured using body plethysmography. After a 35 Kcal/kg diet including 20-40% fat, 40% protein and 20% carbohydrates, these patients were followed by monthly scheduled visits. Spirometric parameters were measured again 3 and 6 months later and the results were analyzed using Freedman method. Pulmonary function tests of the under study patients at the beginning, 3 and 6 months later were as follows respectively; FEV1; 18.3%, 19.57%, 20.95%, airways resistance; 65.3%, 63.7%, 64.9% and maximal inspiratory pressure (MIP); 2.59, 3.062 and 3.29 cmH2O. There was a significant difference in FEV1 and MIP of patients in 3 and 6 months period (P<0.05). Meanwhile, there was no significant difference in airways resistance of patients (P=0.08). Improved nutrition results in increased MIP and FEV1 without changing in other indices (i.e. constant airways resistance indicates constant treatment status of the patient). Thus, an appropriate nutritional diet including sufficient calorie with small frequent meals at least for six months can increase FEV1 by reinforcing inspiratory muscles resulting in improved pulmonary function. (Tanaffos 2005; 4(15): 33-36)