Additionally, it has been observed that high-fat-diet (HFD)-induced obesity enhanced the expression of TGF-β1 and insulin resistance in the lungs, which causes perivascular and peribronchial pulmonary fibrosis and aggravated airway hyper-responsiveness (AHR) to inhaled aerosolized methacholine (MCh) in mice [55]. Here, TGFB1 is linked to pulmonary fibrosis.