Addition of tiotropium to formoterol improves inspiratory muscle strength after exercise in COPD

Background: the addition of tiotropium bromide (110) to formoterol fumarate (FOR) improves exercise performance in patients with chronic obstructive pulmonary disease (COPD). in this study, we test the hypothesis that the addition of TIO to for may improve respiratory muscle performance and oxygen uptake kinetics after exercise in patients with COPD.Methods: Thirty eight patients with COPD were randomized to a 2 week treatment with for 12 mu g twice a day plus TIO 18 mu g once a day (FOR + TIO) or for 12 mu g twice a day plus placebo (FOR + PLA) once a day, using a double-blind crossover design. Inspiratory muscle. Strength was measured before, immediately after, as well as 2, 5, and 10 min during recovery of exercise. Time to limit of tolerance on a constant work load exercise test and oxygen uptake kinetics during recovery were evaluated before and after intervention.Results: Only for + TIO improved resting (63 +/- 10 cm to 84 +/- 11 cmH(2)O) and post-exercise (49 +/- 7 cm to 84 +/- 11 cmH(2)O) maximal inspiratory pressure. Time to limit of tolerance on the constant work load test was increased by for + PLA and by for + TIO, but the size of the increment was significantly larger with for + TIO (40.7 +/- 7.6% vs. 84.5 +/- 8.2%; p < 0.05). Only for + TIO improved oxygen uptake kinetics during recovery (69 +/- 21 to 60 +/- 18s). the improvement in maximal inspiratory pressure (0.78, p < 0.001) and in oxygen uptake kinetics (-0.91, p < 0.001) correlated with the change in time to the limit of tolerance.Conclusions: the addition of TIO to for improves inspiratory muscle strength and oxygen uptake kinetics after exercise in COPD patients. (C) 2012 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Hosp Clin Porto Alegre, Exercise Pathophysiol Res Lab, Porto Alegre, RS, BrazilHosp Clin Porto Alegre, Div Cardiol, Porto Alegre, RS, BrazilUniv So Santa Catarina, Exercise Biochem & Physiol Lab, Postgrad Program Hlth Sci, Hlth Sci Unit, Criciuma, BrazilUniv Fed Rio Grande do Sul, Dept Med, Fac Med, Porto Alegre, RS, BrazilUniversidade Federal de São Paulo, Pulm Funct & Clin Exercise Physiol Unit SEFICE, Div Resp, Dept Med, São Paulo, BrazilPaulista Sch Med UNIFESP EPM, São Paulo, BrazilUniversidade Federal de São Paulo, Pulm Funct & Clin Exercise Physiol Unit SEFICE, Div Resp, Dept Med, São Paulo, BrazilPaulista Sch Med UNIFESP EPM, São Paulo, BrazilWeb of Scienc