Body Mass and Fat-Free Mass Indices in COPD* Relation With Variables Expressing Disease Severity Eleni Ischaki, MD; Georgios Papatheodorou, PhD; Eleni Gaki, MD; Ioli Papa, MD; Nikolaos Koulouris, MD, PhD; and Stelios Loukides, MD, FCCP Background: COPD primarily affects the lungs but also produces systemic consequences that are not reflected by the recent staging according to Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines. Body mass index (BMI) and fat-free mass index (FFMI) represent different aspects of nutrition abnormalities in COPD. We investigated whether BMI and FFMI could be related to parameters expressing airflow obstruction and limitation, exercise capacity, airway inflammation, and quality of life, and whether they would reflect the GOLD staging of the disease. Methods: One hundred patients with clinically stable COPD equally classified into the five stages of the disease were evaluated for BMI, FFMI (measured by bioelectrical impedance analysis), airway obstruction and hyperinflation (FEV 1 , FEV 1 /FVC, inspiratory capacity), exercise capacity (6-min walk distance [6MWD], Borg scale before and after 6MWD]), chronic dyspnea using the Medical Research Council (MRC) scale, airway inflammation (sputum differential cell counts, leukotriene B 4 in supernatant), and quality of life (emotional part of the chronic respiratory disease questionnaire). Results: 6MWD was significantly associated with both BMI and FFMI values, while FFMI additionally presented significant correlations with MRC scale, percentage of predicted FEV 1 , and FEV 1 /FVC ratio. No association was observed between the two nutritional indexes. BMI was not statistically different among patients in the five stages of COPD, while FFMI reflected the staging of the disease, presenting the highest values in stage 0. Conclusions: Nutritional status is mainly related to exercise capacity. FFMI seems to be more accurate in expressing variables of disease severity, as well as the current staging compared to BMI. (CHEST 2007; 132:164 –169) Key words: airway obstruction; body mass index; COPD; exercise capacity; fat-free mass index Abbreviations: BMI = body mass index; Borg = difference in breathlessness in Borg scale; CRQ = chronic respiratory disease questionnaire; FEV 1 %pred = percentage of predicted FEV 1 ; FFM = fat-free mass; FFMI = fat-free mass index; GOLD = Global Initiative for Chronic Obstructive Lung Disease; IC = inspiratory capacity; LTB 4 = leukotriene B 4 ; MRC = Medical Research Council; 6MWD = 6-min walk distance C OPD is characterized by a range of pathophysi- ologic changes contributing to a highly variable clinical presentation as well as heterogeneity among the patients. One of the main consequences of the disease is the progressive loss of skeletal muscle mass and the presence of several bioenergetic abnormal- ities, mainly expressed by weight loss. 1 The above systemic effects might enhance significantly clinical symptoms, such as limitation of exercise capacity, and have a negative impact on quality of life. 2,3 *From the Department of Pneumonology (Drs. Ischaki, Gaki, and Papa), Veterans Hospital of Athens; Clinical Research Unit (Dr. Papatheodorou), Athens Army General Hospital; and First Respira- tory Medicine Department (Drs. Koulouris and Loukides), Univer- sity of Athens Medical School, Athens, Greece. This work was performed at the Department of Pneumonology, Veterans Hospital of Athens, Greece. The authors have no conflicts of interest to disclose. Manuscript received November 16, 2006; revision accepted March 7, 2007. Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal. org/misc/reprints.shtml). Correspondence to: Stelios Loukides, MD, FCCP, Smolika 2, 16673 Athens, Greece; e-mail: ssat@hol.gr DOI: 10.1378/chest.06-2789 Original Research COPD 164 Original Research