Effects of whole-body exercise training on body composition and functional capacity in normal-weight patients with COPD.
BACKGROUND
Skeletal muscle wasting is related to muscle dysfunction, exercise intolerance, and increased mortality risk in patients with COPD.


OBJECTIVE
The aims of this study were to investigate the effects of whole-body exercise training on body composition in normal-weight patients with COPD, and to study the relationship between changes in body composition and functional capacity.


METHODS
Fifty patients with COPD (FEV(1), 39% of predicted [SD, 16]) admitted to the pulmonary rehabilitation center at Hornerheide, and 36 healthy age-matched control subjects (for baseline comparison) were included.


METHODS
Patients participated in a standardized inpatient exercise training program consisting of daily submaximal cycle ergometry, treadmill walking, weight training, and gymnastics during 8 weeks.


METHODS
Fat-free mass (FFM) was measured by bioelectrical impedance analysis. None of the patients met the criteria for nutritional supplementation (body mass index </= 21, or FFM index </= 15 kg/m(2) in women and </= 16 kg/m(2) in men). Exercise capacity was measured using incremental cycle ergometry. Isokinetic quadriceps strength was measured with a Biodex dynamometer (Biodex Medical Corporation; Shirley, NY).


RESULTS
At baseline, patients were characterized by a significantly lower FFM than the control subjects. Age and FFM were independent predictors of skeletal muscle function and exercise capacity in patients. After rehabilitation, weight (72.4 +/- 9.8 to 73.0 +/- 9.4 kg, p < 0.05) significantly increased, as a result of increased FFM (52.4 +/- 7.3 to 53.4 +/- 7.7 kg, p < 0.05), while fat mass (20.0 +/- 6.1 to 19.6 +/- 5.7 kg) tended to decrease. Peak work rate (63 +/- 29 to 84 +/- 42 W, p < 0.001), maximal oxygen consumption (O(2)max) [1,028 +/- 307 to 1,229 +/- 421 mL/min, p < 0.001], and isokinetic quadriceps strength (82.5 +/- 36.4 to 90.3 +/- 34.9 Newton-meters, p < 0.05) all improved. Changes in FFM were proportionally smaller than functional improvements, and were related to changes in O(2)max (r = 0.361, p < 0.05), but not to other changes in functional capacity.


CONCLUSIONS
Intensive exercise training per se is able to induce an anabolic response in normal-weight patients with COPD classified into Global Initiative for Chronic Obstructive Lung Disease stages III-IV. Improvements in exercise performance and muscle function are proportionally larger than increases in FFM.
Franssen
Frits M E
FM
Department of Respiratory Medicine, University Hospital Maastricht, Maastricht, Germany. f.franssen@pul.unimaas.nl
Broekhuizen
Roelinka
R
Janssen
Paul P
PP
Wouters
Emiel F M
EF
Schols
Annemie M W J
AM
D000368:Aged; D001823:Body Composition / Q000502:physiology*; D001835:Body Weight; D016022:Case-Control Studies; D015331:Cohort Studies; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010806:Physical Education and Training / Q000379:methods*; D010807:Physical Endurance; D011336:Probability; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000534:rehabilitation*; D012016:Reference Values; D012129:Respiratory Function Tests; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index