title: Quadriceps fatigability after single muscle exercise in patients with chronic obstructive pulmonary disease.
abstract: The purpose of this study was to compare quadriceps fatigability in patients with varying severity of chronic obstructive pulmonary disease with age-matched control subjects. Ten healthy control subjects, 8 patients with severe disease (FEV1 less than 35% predicted), and 11 patients with mild to moderate disease were studied. The FEV1 was 1.75 +/- 0.13 L (SE), 50.4 +/- 2.9% of predicted in the mild to moderate group, and 0.87 +/- 0.06 L, 25.9 +/- 1.9% of predicted in the severe group. Quadriceps fatigue was quantified by the reduction in potentiated twitch force after a potentially fatiguing task. All subjects performed three sets of 10 maximum voluntary contractions of the right quadriceps muscle. Quadriceps maximum voluntary contraction force was 58.3 +/- 3.3 kg for the healthy older group, 49.0 +/- 4.2 kg in the mild to moderate group, and 44.3 +/- 4.7 kg in the severe group. The fall in potentiated twitch force after exercise was significantly greater in the patients with severe disease than in the healthy control subjects. In conclusion, the quadriceps in patients with severe chronic obstructive pulmonary disease are more fatigable than those in age- and sex-matched healthy control subjects.
authors.affiliation: Division of Pulmonary, Critical Care and Sleep Medicine, Section 111S, State University of New York at Buffalo, Veterans Administration Medical Center, 3495 Bailey Avenue, Buffalo, New York 14215, USA. mador@acsu.buffalo.edu
authors.forename: M Jeffery
authors.initials: MJ
authors.lastname: Mador
authors.forename: Omer
authors.initials: O
authors.lastname: Deniz
authors.forename: Ajay
authors.initials: A
authors.lastname: Aggarwal
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Kufel
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D015992:Body Mass Index; D016022:Case-Control Studies; D005080:Exercise Test; D017079:Exercise Tolerance; D005541:Forced Expiratory Volume; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D018763:Muscle Fatigue; D010807:Physical Endurance; D029424:Pulmonary Disease, Chronic Obstructive / Q000145:classification / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D012720:Severity of Illness Index; D012907:Smoking / Q000009:adverse effects / Q000503:physiopathology; D013848:Thigh; D014797:Vital Capacity