RESUMO
PURPOSE: Obesity results in decreased lung function and increased inflammation. Moderate aerobic exercise (AE) reduced lung inflammation and remodeling in a variety of respiratory disease models. Therefore, this study investigated whether AE can attenuate a diet-induced obesity respiratory phenotype; including airway hyper-responsiveness (AHR), remodeling and inflammation. METHODS: Sixty C57Bl/6 male mice were distributed into four groups: control lean (CL), exercise lean (EL), obese (O) and obese exercise (OE) groups (2 sets of 7 and 8 mice per group; nâ¯=â¯15). A classical model of diet-induced obesity (DIO) over 12â¯weeks was used. AE was performed 60â¯min/day, 5â¯days/week for 5â¯weeks. Airway hyperresponsiveness (AHR), lung inflammation and remodeling, adipokines and cytokines in bronchoalveolar lavage (BAL) was determined. RESULTS: A high fat diet over 18â¯weeks significantly increased body weight (pâ¯<â¯.0001). Five weeks of AE significantly reduced both AHR and pulmonary inflammation. AHR in obese mice that exercised was reduced at the basal level (pâ¯<â¯.05), vehicle (PBS) (pâ¯<â¯.05), 6.25 MCh mg/mL (pâ¯<â¯.05), 12.5 MCh mg/mL (pâ¯<â¯.01), 25 MCh mg/mL (pâ¯<â¯.01) and 50 MCh mg/mL (pâ¯<â¯.05). Collagen (pâ¯<â¯.001) and elastic (pâ¯<â¯.001) fiber deposition in airway wall and also smooth muscle thickness (pâ¯<â¯.001) were reduced. The number of neutrophils (pâ¯<â¯.001), macrophages (pâ¯<â¯.001) and lymphocytes (pâ¯<â¯.01) were reduced in the peribronchial space as well as in the BAL: lymphocytes (pâ¯<â¯.01), macrophages (pâ¯<â¯.01), neutrophils (pâ¯<â¯.001). AE reduced obesity markers leptin (pâ¯<â¯.001), IGF-1 (pâ¯<â¯.01) and VEGF (pâ¯<â¯.001), while increased adiponectin (pâ¯<â¯.01) in BAL. AE also reduced pro-inflammatory cytokines in the BAL: IL-1ß (pâ¯<â¯.001), IL-12p40 (pâ¯<â¯.001), IL-13 (pâ¯<â¯.01), IL-17 (pâ¯<â¯.001, IL-23 (pâ¯<â¯.05) and TNF-alpha (pâ¯<â¯.05), and increased anti-inflammatory cytokine IL-10 (pâ¯<â¯.05). CONCLUSIONS: Aerobic exercise reduces high fat diet-induced obese lung phenotype (AHR, pulmonary remodeling and inflammation), involving anti-inflammatory cytokine IL-10 and adiponectin.