New treatments for chronic obstructive pulmonary disease using ergogenic aids

Chronic obstructive pulmonary disease is currently considered a systemic disease, presenting structural and metabolic alterations that can lead to skeletal muscle dysfunction. This negatively affects the performance of respiratory and peripheral muscles, functional capacity, health-related quality of life and even survival. The decision to prescribe ergogenic aids for patients with chronic obstructive pulmonary disease is based on the fact that these drugs can avert or minimize catabolism and stimulate protein synthesis, thereby reducing the loss of muscle mass and increasing exercise tolerance. This review summarizes the available data regarding the use of anabolic steroids, creatine, L-carnitine, branched-chain amino acids and growth hormones in patients with chronic obstructive pulmonary disease. The advantage of using these ergogenic aids appears to lie in increasing lean muscle mass and inducing bioenergetic modifications. Within this context, most of the data collected deals with anabolic steroids. However, to date, the clinical benefits in terms of increased exercise tolerance and muscle strength, as well as in terms of the effect on morbidity and mortality, have not been consistently demonstrated. Dietary supplementation with substances of ergogenic potential might prove to be a valid adjuvant therapy for treating patients with advanced chronic obstructive pulmonary disease, especially those presenting loss of muscle mass or peripheral muscle weakness.A doença pulmonar obstrutiva crônica é considerada, atualmente, uma doença sistêmica, cujas alterações estruturais e metabólicas podem levar à disfunção muscular esquelética. Esta afeta negativamente o desempenho muscular respiratório e periférico, a capacidade funcional, a qualidade de vida relacionada à saúde e mesmo a sobrevida. A indicação de suplementação de substâncias ergogênicas para pacientes com doença pulmonar obstrutiva crônica baseia-se no fato de que estas drogas podem evitar, ou minimizar, o catabolismo e/ou estimular a síntese protéica, diminuindo a depleção de massa muscular e aumentando a capacidade de exercício. A presente revisão sumariza o conhecimento disponível acerca da utilização de esteróides anabolizantes, creatina, L-carnitina, aminoácidos de cadeia ramificada e hormônio de crescimento em pacientes com doença pulmonar obstrutiva crônica. A vantagem do uso dessas substâncias ergogênicas parece residir no aumento da massa magra e/ou na indução de modificações bioenergéticas. Nesse contexto, a maior experiência acumulada é com os esteróides anabolizantes. Entretanto, os benefícios clínicos em relação à melhora da capacidade de exercício e força muscular, bem como os efeitos na morbimortalidade, não foram, até a presente data, consistentemente demonstrados. A suplementação ergogênica pode vir a se constituir numa ferramenta adjuvante para o tratamento de pacientes com doença pulmonar obstrutiva crônica avançada, especialmente naqueles com depleção muscular e/ou fraqueza periférica.Universidade Federal de São Paulo (UNIFESP) Setor de Função Pulmonar e Fisiologia Clínica do ExercícioUniversidade Federal de São Paulo (UNIFESP)UNIFESP, Setor de Função Pulmonar e Fisiologia Clínica do ExercícioUNIFESPSciEL

Inspiratory fraction and exercise impairment in COPD patients GOLD stages II-III

The inspiratory-to-total lung capacity ratio or inspiratory fraction (inspiratory capacity (IC)/total lung capacity (TLC)) may be functionally more representative than traditional indices of resting airflow limitation and lung hyperinflation in patients with chronic obstructive pulmonary disease (COPD).In the present retrospective study, a comparison was made of the individual performance of post-bronchodilator IC, IC/TLC and forced expiratory volume in one second (FEV1) in predicting a severely reduced peak oxygen uptake (V'o(2); < 60% predicted) in 44 COPD patients Global Initiative for Chronic Obstructive Lung Disease stages II-III (post-bronchodilator FEV1 ranging from 31-79% pred).Patients with lower IC/TLC values (<= 0.28) showed increased lung volumes and reduced exercise capacity as compared with other subjects. Following a multiple linear regression analysis, only IC/TLC and FEV1 remained as independent predictors of V'o(2) (r(2)=0.33). A receiver operating characteristic (ROC) curve analysis revealed that an IC/TLC <= 0.28 had the highest specificity (89.6%), positive predictive value (80%) and overall accuracy (86.3%) in identifying patients with V'o(2)< 60% pred. in addition, the area under the ROC curve tended to be higher for IC/TLC than IC.In conclusion, post-bronchodilator total lung capacity-corrected inspiratory fraction provides useful information in addition to forced expiratory volume in one second and inspiratory capacity, to estimate the likelihood of chronic obstructive pulmonary disease patients to present with severely reduced maximal exercise capacity.Universidade Federal de São Paulo, Paulista Sch Med, Pulm Funct & Clin Exercise Physiol Unit, Resp Div,Dept Med,EPM, BR-04020050 São Paulo, BrazilUniversidade Federal de São Paulo, Paulista Sch Med, Pulm Funct & Clin Exercise Physiol Unit, Resp Div,Dept Med,EPM, BR-04020050 São Paulo, BrazilWeb of Scienc