Body composition in patients with chronic hypercapnic respiratory failure.
OBJECTIVE
To evaluate the contribution of body composition measurements to clinical assessment in patients on home nasal positive-pressure ventilation for chronic hypercapnic respiratory failure (CHRF), and their relationship to respiratory impairment.


METHODS
Patients with CHRF (restrictive lung disease (RLD), n=37; chronic obstructive pulmonary disease (COPD), n=19), during elective yearly evaluations underwent pulmonary function testing (forced expiratory volumes, arterial blood gases, maximal inspiratory and expiratory pressure (PI(max) or PE(max))), and bioelectrical impedance analysis to determine fat-free mass (FFM) index (kg/m(2)) and body fat mass index.


RESULTS
When compared with age- and sex-matched healthy controls, RLD patients (OR 5.5, CI 1.9-15.6, P<0.002) and COPD (OR 5.2, CI 1.1-24.9, P=0.04) were significantly more likely to have a low FFM index. Roughly one-half of patients with RLD and one-third with COPD had abnormally low FFM index. Estimation of nutritional status by body mass index (BMI) alone clearly underestimated the prevalence of FFM index depletion. Muscle mass assessed by FFM index explained 26% of variance of PI(max) (P<0.001) and 27% of that of PE(max) (P<0.001).


CONCLUSIONS
BMI alone clearly underestimated FFM depletion, and presence of a very high body fat mass index. Indeed, normal or high BMI can be associated with FFM depletion. Because of its relationship to respiratory muscle strength, an assessment of FFM appears to be valuable in CHRF.
Kyle
Ursula G
UG
Division of Clinical Nutrition, Geneva University Hospital, Rue Micheli-du-Crest 24, 1211 Geneva, Switzerland.
Janssens
Jean-Paul
JP
Rochat
Thierry
T
Raguso
Comasia A
CA
Pichard
Claude
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001823:Body Composition / Q000502:physiology*; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D006935:Hypercapnia / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration / Q000379:methods; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D012131:Respiratory Insufficiency / Q000503:physiopathology*; D014797:Vital Capacity / Q000502:physiology