NUTRITIONAL DEPLETION IN RELATION TO RESPIRATORY AND PERIPHERAL SKELETAL-MUSCLE FUNCTION IN OUT-PATIENTS WITH COPD

Although increasing attention has been paid to nutritional aspects in chronic obstructive pulmonary disease (COPD), limited information is a vailable regarding the prevalence and consequences of nutritional depl etion in a random out-patient COPD population. We studied body composi tion in relation to respiratory and peripheral skeletal muscle functio n in 72 COPD patients (mean (SD) forced expiratory volume in one secon d (FEV(1)) 53 (15)% predicted), who came to the lung function laborato ry for routine lung function measurements. Patients were characterized by the degree of body weight loss and fat-free mass depletion. Accord ing to this definition, 14% of the group suffered from both loss of bo dy weight and depletion of fat-free mass, whereas 7% had one of these conditions. We found that tissue depletion was concomitant with lower values for respiratory and peripheral skeletal muscle strength (46.0 ( 27.2) vs 77.1 (29.8) kg), and a significantly lower transfer coefficie nt for carbon monoxide (Kco 64.9 (16.2) vs 81.9 (24.5)% pred). Stratif ication by Kco (<60% vs >80%) also revealed significantly lower values for fat-free mass and higher values for intrathoracic gas volumes, to tal lung capacity (TLC) and residual volume (RV) in the group with a K co <60% pred. Analysis of covariance, taking fat-free mass as covariat e, indicated an independent contribution of Kco on maximal inspiratory mouth pressure (Pmax) but not on peripheral skeletal muscle strength. It is concluded that a substantial number of COPD out-patients suffer from nutritional depletion, preferentially affecting peripheral skele tal muscle function.