title: Nutritional status is related to fat-free mass, exercise capacity and inspiratory strength in severe chronic obstructive pulmonary disease patients.
abstract: BACKGROUND
  Being overweight or obese is associated with a higher rate of survival in patients with advanced chronic obstructive pulmonary disease (COPD). This paradoxical relationship indicates that the influence of nutritional status on functional parameters should be further investigated.
  
  
  OBJECTIVE
  To investigate the impact of nutritional status on body composition, exercise capacity and respiratory muscle strength in severe chronic obstructive pulmonary disease patients.
  
  
  METHODS
  Thirty-two patients (nine women) were divided into three groups according to their body mass indices (BMI): overweight/obese (25 < or = BMI < or = 34.9 kg/m(2), n=8), normal weight (18.5 < or = BMI < or = 24.9 kg/m(2), n=17) and underweight (BMI <18.5 kg/m(2), n=7). Spirometry, bioelectrical impedance, a six-minute walking distance test and maximal inspiratory and expiratory pressures were assessed.
  
  
  RESULTS
  Airway obstruction was similar among the groups (p=0.30); however, overweight/obese patients had a higher fat-free mass (FFM) index [FFMI=FFM/body weight(2) (mean+/-SEM: 17+/-0.3 vs. 15+/-0.3 vs. 14+/-0.5 m/kg(2), p<0.01)], exercise capacity (90+/-8 vs. 79+/-6 vs. 57+/-8 m, p=0.02) and maximal inspiratory pressure (63+/-7 vs. 57+/-5 vs. 35+/-8 % predicted, p=0.03) in comparison to normal weight and underweight patients, respectively. In addition, on backward multiple regression analysis, FFMI was the unique independent predictor of exercise capacity (partial r=0.52, p<0.01).
  
  
  CONCLUSIONS
  Severe chronic obstructive pulmonary disease (COPD) patients who were overweight or obese had a greater FFM, exercise capacity and inspiratory muscle strength than patients with the same degree of airflow obstruction who were of normal weight or underweight, and higher FFM was independently associated with higher exercise capacity. These characteristics of overweight or obese patients might counteract the drawbacks of excess weight and lead to an improved prognosis in COPD.
authors.affiliation: Department of Physical Therapy, Londrina State University, Paraná, Brazil. sabino.pg@gmail.com
authors.forename: Pollyane Galinari
authors.initials: PG
authors.lastname: Sabino
authors.forename: Bruno Moreira
authors.initials: BM
authors.lastname: Silva
authors.forename: Antonio Fernando
authors.initials: AF
authors.lastname: Brunetto
mesh_terms: D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D001835:Body Weight; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology; D009752:Nutritional Status / Q000502:physiology*; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D012132:Respiratory Muscles / Q000503:physiopathology; D013851:Thinness / Q000503:physiopathology