In the COPD group, serum d–ROMs levels were correlated with IL-6, SAA, and CRP levels and with WBC, neutrophil, and eosinophil counts (rs = 0487, p < 0.001; rs = 0.408, p < 0.001; rs = 0.431, p < 0.001; rs = 0.265, p = 0.036; rs = 0.265, p = 0.036; rs = 0.431, p < 0.001, respectively). Here, IL6 is linked to chronic obstructive pulmonary disease.