Am. J. Respir. Crit. Care Med., Volume 158, Number 2, August 1998, 629-634

Peripheral Muscle Weakness in Patients with Chronic Obstructive Pulmonary Disease

SARAH BERNARD, PIERRE LEBLANC, FRANÇOIS WHITTOM, GUY CARRIER, JEAN JOBIN, ROGER BELLEAU, and FRANÇOIS MALTAIS

Unité de Recherche, Institut de Cardiologie et de Pneumologie de Québec, Université Laval, Ste-Foy, Québec, Canada

Peripheral muscle weakness is commonly found in patients with chronic obstructive pulmonary disease (COPD) and may play a role in reducing exercise capacity. The purposes of this study were to evaluate, in patients with COPD: (1) the relationship between muscle strength and cross-sectional area (CSA), (2) the distribution of peripheral muscle weakness, and (3) the relationship between muscle strength and the severity of lung disease. Thirty-four patients with COPD and 16 normal subjects of similar age and body mass index were evaluated. Compared with normal subjects, the strength of three muscle groups (p < 0.05) and the right thigh muscle CSA, evaluated by computed tomography (83.4 ± 16.4 versus 109.6 ± 15.6 cm², p < 0.0001), were reduced in COPD. The quadriceps strength/thigh muscle CSA ratio was similar for the two groups. The reduction in quadriceps strength was proportionally greater than that of the shoulder girdle muscles (p < 0.05). Similar observations were made whether or not patients had been exposed to systemic corticosteroids in the 6-mo period preceding the study, although there was a tendency for the quadriceps strength/thigh muscle CSA ratio to be lower in patients who had received corticosteroids. In COPD, quadriceps strength and muscle CSA correlated positively with the FEV₁ expressed in percentage of predicted value (r = 0.55 and r = 0.66, respectively, p < 0.0005). In summary, the strength/muscle cross-sectional area ratio was not different between the two groups, suggesting that weakness in COPD is due to muscle atrophy. In COPD, the distribution of peripheral muscle weakness and the correlation between quadriceps strength and the degree of airflow obstruction suggests that chronic inactivity and muscle deconditioning are important factors in the loss in muscle mass and strength.

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				M. P. K. J. ENGELEN, E. F. M. WOUTERS, N. E. P. DEUTZ, J. D. DOES, and A. M. W. J. SCHOLS Effects of Exercise on Amino Acid Metabolism in Patients with Chronic Obstructive Pulmonary Disease Am. J. Respir. Crit. Care Med., March 15, 2001; 163(4): 859 - 864. [Abstract] [Full Text]

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				M. Yoshikawa, T. Yoneda, H. Takenaka, A. Fukuoka, Y. Okamoto, N. Narita, and K. Nezu Distribution of Muscle Mass and Maximal Exercise Performance in Patients With COPD Chest, January 1, 2001; 119(1): 93 - 98. [Abstract] [Full Text] [PDF]

				M C Steiner and M D L Morgan Enhancing physical performance in chronic obstructive pulmonary disease Thorax, January 1, 2001; 56(1): 73 - 77. [Full Text]

				M. P. K. J. ENGELEN, N. E. P. DEUTZ, E. F. M. WOUTERS, and A. M. W. J. SCHOLS Enhanced Levels of Whole-body Protein Turnover in Patients with Chronic Obstructive Pulmonary Disease Am. J. Respir. Crit. Care Med., October 1, 2000; 162(4): 1488 - 1492. [Abstract] [Full Text] [PDF]

				L. M A Heunks and P N R. Dekhuijzen Respiratory muscle function and free radicals: from cell to COPD Thorax, August 1, 2000; 55(8): 704 - 716. [Full Text]

				P. J. Barnes Chronic Obstructive Pulmonary Disease N. Engl. J. Med., July 27, 2000; 343(4): 269 - 280. [Full Text] [PDF]

				H. R Gosker, E. F. Wouters, G. J van der Vusse, and A. M. Schols Skeletal muscle dysfunction in chronic obstructive pulmonary disease and chronic heart failure: underlying mechanisms and therapy perspectives Am. J. Clinical Nutrition, May 1, 2000; 71(5): 1033 - 1047. [Abstract] [Full Text] [PDF]

				R. Casaburi Skeletal Muscle Function in COPD Chest, May 1, 2000; 117(5_suppl_1): 267S - 271S. [Abstract] [Full Text] [PDF]

				M. P. Engelen, A. M. Schols, J. D Does, and E. F. Wouters Skeletal muscle weakness is associated with wasting of extremity fat-free mass but not with airflow obstruction in patients with chronic obstructive pulmonary disease Am. J. Clinical Nutrition, March 1, 2000; 71(3): 733 - 738. [Abstract] [Full Text] [PDF]

				E. Clini, L. Bianchi, M. Vitacca, R. Porta, K. Foglio, and N. Ambrosino Exhaled Nitric Oxide and Exercise in Stable COPD Patients Chest, March 1, 2000; 117(3): 702 - 707. [Abstract] [Full Text] [PDF]

				T. Rantanen, T. Harris, S. G. Leveille, M. Visser, D. Foley, K. Masaki, and J. M. Guralnik Muscle Strength and Body Mass Index as Long-Term Predictors of Mortality in Initially Healthy Men J. Gerontol. A Biol. Sci. Med. Sci., March 1, 2000; 55(3): 168M - 173. [Abstract] [Full Text]

				M. JEFFERY MADOR, T. J. KUFEL, and L. PINEDA Quadriceps Fatigue after Cycle Exercise in Patients with Chronic Obstructive Pulmonary Disease Am. J. Respir. Crit. Care Med., February 1, 2000; 161(2): 447 - 453. [Abstract] [Full Text]