title: Nutritional depletion and its relationship to respiratory impairment in patients with chronic respiratory failure due to COPD or restrictive thoracic diseases.
abstract: OBJECTIVE
  While malnutrition, especially fat-free mass index (FFMI), is a predictor for mortality in chronic obstructive pulmonary disease (COPD), less information on prevalence and mechanisms is available in patients with chronic respiratory failure (CRF) due to restrictive thoracic diseases (RTD).
  
  
  METHODS
  Cross-sectional study of patients consecutively admitted to an in-patient primary pulmonary centre.
  
  
  METHODS
  One hundred and thirty-two patients (30% RTD; 70% COPD) with CRF and intermittent non-invasive positive pressure ventilation.
  
  
  METHODS
  Malnutrition was quantified by bioelectrical impedance analysis or body mass index (BMI), and its relationship to laboratory, lung function, inspiratory muscle and blood gas parameters and 6-min walking distance (6-MWD) was assessed.
  
  
  RESULTS
  Malnutrition in terms of BMI<20 kg/m(2) occurred in 16.1% of patients with COPD but none of those with RTD. FFMI<17.4 (<15.0 in female patients) kg/m(2) was found in 35.4 and 30.7%, respectively. FFMI was correlated with airway obstruction (sR(aw), r = -0.50; FEV(1)/VC, r = -0.28; P< or = 0.01 each) and lung hyperinflation (intrathoracic gas volume, r = -0.41; total lung capacity (TLC), r = -0.50; P< or = 0.001 each) in COPD, and with lung restriction in RTD (TLC, r=0.40; P=0.011). Furthermore, malnourished patients showed a higher inspiratory load (P (0.1)) and reduced 6-MWD in both groups. In COPD, only hyperinflation and P (0.1) were independently related to FFMI.
  
  
  CONCLUSIONS
  Malnutrition as indicated by low FFMI was similarly prevalent in patients with CRF and COPD or RTD, but inadequately represented by BMI. The correlations between lung function impairments specific for the disease and FFMI emphasized the link between malnutrition and respiratory mechanical load irrespective of its aetiology.
authors.affiliation: Center for Pneumology, Donaustauf Hospital, Donaustauf, Germany. stephan.budweiser@klinik.uni-regensburg.de
authors.forename: S
authors.initials: S
authors.lastname: Budweiser
authors.forename: K
authors.initials: K
authors.lastname: Meyer
authors.forename: R A
authors.initials: RA
authors.lastname: Jörres
authors.forename: F
authors.initials: F
authors.lastname: Heinemann
authors.forename: P J
authors.initials: PJ
authors.lastname: Wild
authors.forename: M
authors.initials: M
authors.lastname: Pfeifer
mesh_terms: D001784:Blood Gas Analysis; D015992:Body Mass Index; D015897:Comorbidity; D003430:Cross-Sectional Studies; D017097:Electric Impedance; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D044342:Malnutrition / Q000150:complications / Q000453:epidemiology* / Q000401:mortality; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology; D009752:Nutritional Status; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000453:epidemiology* / Q000401:mortality; D012129:Respiratory Function Tests; D012131:Respiratory Insufficiency / Q000150:complications / Q000453:epidemiology* / Q000401:mortality; D013896:Thoracic Diseases / Q000150:complications / Q000453:epidemiology* / Q000401:mortality; D014797:Vital Capacity