Body composition in patients with chronic obstructive pulmonary disease.

OBJECTIVES: Body composition assessment in chronic obstructive pulmonary disease (COPD) is important, as weight loss and muscular wasting are responsible for low exercise capacity in these patients, and low body mass index (BMI) and fat free mass index (FFMI) are important prognostic factors. Our study aims were: (a) to describe body composition in COPD patients referred to a pulmonary rehabilitation center in Bucharest; (b) to examine the relationships between body composition and disease severity (bronchial obstruction, exercise capacity, quality of life); (c) to test if segmental wasting of lower limbs muscle mass (measured by segmental body composition analysis) correlates with decreased exercise capacity.
MATERIAL AND METHODS: We studied 36 consecutive COPD patients referred to our clinic for pulmonary rehabilitation. Patients performed pulmonary function tests, six minutes walking test (6MWT), and health status was evaluated with COPD Assessment Test (CAT). Body composition measurements were performed by direct segmental multi-frequency bioelectrical impedance analysis (BIA). OUTCOMES: This study offers the first data on body composition of Romanian COPD patientsThe prevalence of nutritional depletion (defined by low BMI and/or low FFMI) among our COPD patients was 22.2%. Mean FFMI was significantly lower in normal or underweight patients versus overweight or obese patients. Patients with low FFMI had lower exercise capacity at the 6MWT and higher CAT scores than patients with normal FFMI.Depending on the BMI and FFMI values the patients were divided in four categories: normal, semistarvation, sarcopenia and cachexia. The group of patients with sarcopenia (low FFMI and normal BMI) had the lowest mean MIP (Maximal Inspiratory Pressure), the lowest mean 6MWD (six minutes walking distance) and the higher CAT mean scores among all groups. Exercise capacity was significantly lower in muscular depleted patients (with low skeletal muscle mass index - SSMI). MIP correlated significantly with FFMI and SMMI. No correlations were found between parameters of body composition and FEV1 or CAT. Segmental body composition assessment revealed that unbalanced upper/lower skeletal muscle mass is associated with a lower exercise capacity as measured by 6WMT.
CONCLUSIONS: This study offers the first data on body composition of Romanian COPD patients. The prevalence of nutritional depletion is similar to that found in other European studies. No significant correlations were found between FFMI and severity of the disease (bronchial obstruction, distance walked, CAT score). FFMI and SSMI correlated significantly with MIP. Sarcopenic patients had the lowest mean 6MWD, the lowest mean MIP and the highest CAT mean scores. SMMI significantly correlated with 6MWD. Segmental body composition assessment of revealed that "unbalanced" patients had lower results at 6MWT. These results show that body composition evaluation is useful for the assessment of COPD patients referred to pulmonary rehabilitation and should be routinely performed.