Body composition by bioelectrical impedance predicts mortality in chronic obstructive pulmonary disease patients

Pulmonary rehabilitation is recommended in international treatment guidelines for chronic obstructive pulmonary disease (COPD). No one has however studied the effect on long-term mortality. The aim of the current study was to study the mortality in a sample of patients with severe COPD included in a 1-year multidisciplinary rehabilitation program. Body composition was assessed at baseline using bioelectrical impedance. Mortality was studied in 86 patients using the Cox proportional hazards model. Forty-seven (55%) of the patients died during the mean follow-up time which was almost 6 years. Risk of mortality increased with increasing age, increasing number of hospital days the year before inclusion and men had higher mortality risk than women. The mortality risk decreased with increasing % reference body weight, increasing fat-free mass index (FFMI), increasing FEV(1) and increasing 6-min walking distance. Gender, age and FFMI continued to be statistical significant predictors of mortality when controlling for the other baseline variables in a multivariate analysis. To conclude, body composition, measured by bioelectrical impedance and presented as FFMI, is an independent predictor of mortality in COPD patients.