Prevalence and characteristics of nutritional depletion in patients with stable COPD eligible for pulmonary rehabilitation

Abstract

Prevalence and characteristics of nutritional depletion were established by body composition measurements in 255 COPD patients in stable clinical condition admitted to a pulmonary rehabilitation center. Depletion of body weight, fat-free mass (using bioelectrical resistance measurements), and muscle mass [from creatinine height index (CHI) and midarm muscle circumference] was most pronounced (40 to 50%) in patients suffering from chronic hypoxemia and in normoxemic patients with severe airflow obstruction (FEV1 < 35%) but also occurred in +/- 25% of patients with moderate airflow obstruction. Classification of the patients in four groups by body weight and fat-free mass revealed that depletion of fat-free mass may occur in normal-weight COPD patients (Group 3). These patients also exhibit a decreased CHI (61 +/- 21%, mean +/- SD) and suffer from physical impairment (12-min walking distance, WD, 532 +/- 152 m) to an even greater degree than underweight patients with relative preservation of fat-free mass (Group 2) (CHI = 73 +/- 16%; WD = 744 +/- 233 m). No systematic differences were established between the four groups in serum protein concentrations or medication use. We conclude that fat-free mass is a better indicator of body mass depletion than body weight. Classification of COPD patients by body weight and fat-free mass may have consequences for planning and interpretation of intervention strategies, particularly in Group 2 and 3 patients.