ADIPOQ and idiopathic pulmonary fibrosis: Serum adiponectin/leptin (A/L) ratio was negatively correlated with body mass index at AE-IPF (r = −0.456, p = 0.003) and PaO2 before AE-IPF (r = −0.498, p = 0.034), and positively correlated with C-reactive protein at AE-IPF (r = 0.316, p = 0.049).