RELATIONSHIP BETWEEN PERIPHERAL MUSCLE STRUCTURE and FUNCTION in PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE WITH DIFFERENT NUTRITIONAL STATUS
Data
2011-07-01
Tipo
Artigo
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Malaguti, C, Napolis, LM, Villaca, D, Neder, JA, Nery, LE, and Dal Corso, S. Relationship between peripheral muscle structure and function in patients with chronic obstructive pulmonary disease with different nutritional status. J Strength Cond Res 25(7): 1795-1803, 2011-The purpose of this study was to investigate the relationships between peripheral muscle structure (mass) and function (strength, endurance, and maximal aerobic capacity) in patients with chronic obstructive pulmonary disease (COPD) with different nutritional states. Thirty-nine patients (31 male) with moderate-severe COPD (63.5 +/- 7.3 [SD] years) and 17 controls (14 male; 64.7 +/- 5.5 [SD] years) underwent isokinetic (peak torque [PT]), isometric (isometric torque [IT]), and endurance strength (total work [TW]) measurements of the knee extensor muscles and a maximal cardiopulmonary exercise test to evaluate the maximal aerobic capacity (peak oxygen uptake [<(V)over dot>O-2] peak). Muscle mass (MM) was determined using dual-energy x-ray absorptiometry. Patients with COPD presented with reduced muscle function as compared with the healthy controls: PT (105.9 +/- 33.9 vs. 134.3 +/- 30.9, N.m(-1), respectively, p < 0.05), TW (1,446.3 +/- 550.8 vs. 1,792.9 +/- 469.1 kJ, respectively, p < 0.05), and <(V)over dot>(2)peak (68.1 +/- 15.1 vs. 93.7 +/- 14.5, % pred, respectively, p, 0.05). Significant relationships were found between muscle structure and function (strength and endurance) in the patient subgroup with preserved MM and in the control group: PT.MM-1(r(2) = 0.36; p = 0.01 vs. r(2) = 0.32; p = 0.01, respectively) and TW.MM-1 (r(2) = 0.32; p = 0.01 vs. r(2) = 0.22; p = 0.05, respectively). Strength corrected for mass normalized this function in both patient subgroups, whereas endurance was normalized only in the patient subgroup without muscle depletion. Maximal aerobic capacity remained reduced, despite the correction, in both patient subgroups (depleted or nondepleted) compared with the healthy controls (<(V)over dot>(2)peak.MM-1: 9.1 +/- 3.7 vs. 21.8 +/- 4.9 vs. 28.5 +/- 4.2 ml.min.kg(-1), respectively, with p < 0.01 among groups). Muscle atrophy seems to be the main determinant of strength reduction among patients with moderate-severe COPD, whereas endurance reduction seems to be more related to imbalance between oxygen delivery and consumption than to the local muscle structure itself. Peripheral MM did not constitute a good predictor for maximal aerobic capacity in this population. the main practical application of this study is to point out a crucial role for the strategies able to ameliorate cardiorespiratory and muscular fitness in patients with COPD, even in those patients with preserved MM.
Descrição
Citação
Journal of Strength and Conditioning Research. Philadelphia: Lippincott Williams & Wilkins, v. 25, n. 7, p. 1795-1803, 2011.