This Article Full Text Full Text (PDF) Online Supplement All Versions of this Article: 200408-1005OCv1 171/10/1109    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Saey, D. Articles by Maltais, F. Search for Related Content PubMed PubMed Citation Articles by Saey, D. Articles by Maltais, F.

Contractile Fatigue, Muscle Morphometry, and Blood Lactate in Chronic Obstructive Pulmonary Disease

Centre de recherche, Hôpital Laval, Institut Universitaire de Cardiologie et de Pneumologie de l'Université Laval; Centre de recherche du CHUQ pavillon CHUL, Université Laval, Québec, Canada; Laboratoire de Physiologie des Interactions, Hôpital Arnaud de Villeneuve, Montpellier, France; and Pulmonary, Critical Care, and Sleep Medicine, State University of New York at Buffalo and the Buffalo VAMC, Buffalo, New York

Correspondence and requests for reprints should be addressed to Dr. François Maltais, M.D., Centre de Pneumologie, Hôpital Laval, 2725 Chemin Ste-Foy, Ste-Foy, PQ, G1V 4G5 Canada. E-mail: francois.maltais{at}med.ulaval.ca

We hypothesized that patients with chronic obstructive pulmonary disease developing contractile fatigue of the quadriceps during cycle exercise may have characteristic metabolic and muscle features that could increase their susceptibility to fatigue, thus differentiating them from those who do not develop fatigue. We examined, in 32 patients, the fiber-type proportion, enzymatic activities, and capillary density in the vastus lateralis and the arterial blood lactate level during constant work-rate cycling exercise. Contractile fatigue was defined as a postexercise fall in quadriceps twitch force greater than 15% of resting values. Twenty-two patients developed contractile fatigue after exercise. No significant differences were found between fatiguers and nonfatiguers for the endurance time, fiber-type proportion, and oxidative enzyme activities. The lactate dehydrogenase activity was significantly higher (p < 0.05) and muscle capillarization significantly reduced in fatiguers (p < 0.05). Compared with nonfatiguers, the arterial lactate level during exercise was significantly higher in fatiguers (p < 0.001). A significant relationship was found between the fall in quadriceps twitch force and lactate dehydrogenase activity, capillary/fiber ratio, and blood lactate level. We conclude that changes in muscle enzymatic profile and capillarization with a greater reliance on glycolytic metabolism during exercise are associated with contractile fatigue in patients with chronic obstructive pulmonary disease.

Key Words: COPD • exertion • fatigue • muscle

This article has been cited by other articles:

				M A Spruit, H J Pennings, J D Does, G M Moller, P P Janssen, and E F M Wouters Serum LDH and exercise capacity in COPD Thorax, May 1, 2008; 63(5): 472 - 472. [Full Text] [PDF]

				L. D. Calvert, S. J. Singh, P. L. Greenhaff, M. D. Morgan, and M. C. Steiner The plasma ammonia response to cycle exercise in COPD Eur. Respir. J., April 1, 2008; 31(4): 751 - 758. [Abstract] [Full Text] [PDF]

				M. Cazzola, W. MacNee, F. J. Martinez, K. F. Rabe, L. G. Franciosi, P. J. Barnes, V. Brusasco, P. S. Burge, P. M. A. Calverley, B. R. Celli, et al. Outcomes for COPD pharmacological trials: from lung function to biomarkers Eur. Respir. J., February 1, 2008; 31(2): 416 - 469. [Abstract] [Full Text] [PDF]

				E Barreiro, A M W J Schols, M I Polkey, J B Galdiz, H R Gosker, E B Swallow, C Coronell, J Gea, and on behalf of the ENIGMA in COPD project Cytokine profile in quadriceps muscles of patients with severe COPD Thorax, February 1, 2008; 63(2): 100 - 107. [Abstract] [Full Text] [PDF]

				S. C. Erzurum, S. Ghosh, A. J. Janocha, W. Xu, S. Bauer, N. S. Bryan, J. Tejero, C. Hemann, R. Hille, D. J. Stuehr, et al. Higher blood flow and circulating NO products offset high-altitude hypoxia among Tibetans PNAS, November 6, 2007; 104(45): 17593 - 17598. [Abstract] [Full Text] [PDF]

				H. R Gosker, M. P Zeegers, E. F M Wouters, and A. M W J Schols Muscle fibre type shifting in the vastus lateralis of patients with COPD is associated with disease severity: a systematic review and meta-analysis Thorax, November 1, 2007; 62(11): 944 - 949. [Abstract] [Full Text] [PDF]

				E. B. Swallow, H. R. Gosker, K. A. Ward, A. J. Moore, M. J. Dayer, N. S. Hopkinson, A. M. W. J. Schols, J. Moxham, and M. I. Polkey A novel technique for nonvolitional assessment of quadriceps muscle endurance in humans J Appl Physiol, September 1, 2007; 103(3): 739 - 746. [Abstract] [Full Text] [PDF]

				L. M. Fabbri, F. Luppi, B. Beghe, and K. F. Rabe Update in chronic obstructive pulmonary disease 2005. Am. J. Respir. Crit. Care Med., May 15, 2006; 173(10): 1056 - 1065. [Full Text] [PDF]

				E. F. M. Wouters Muscle Wasting in Chronic Obstructive Pulmonary Disease: To Bother and to Measure! Am. J. Respir. Crit. Care Med., January 1, 2006; 173(1): 4 - 5. [Full Text] [PDF]

				T. Troosters, R. Casaburi, R. Gosselink, and M. Decramer Pulmonary Rehabilitation in Chronic Obstructive Pulmonary Disease Am. J. Respir. Crit. Care Med., July 1, 2005; 172(1): 19 - 38. [Full Text] [PDF]