GSTM1 and obesity disorder: Among the preoperative characteristics, male (OR, 95% CI, P: 2.1, 1.09–4.05, 0.026), BMI (OR, 95% CI, P: 1.24, 1.13–1.36, <0.001), obesity (OR, 95% CI, P: 4.42, 2.33–8.39, <0.001), hypertension (OR, 95% CI, P: 1.86, 1.04–3.33, 0.038), fatty liver (OR, 95% CI, P: 1.91, 1.02–3.60, <0.044), heart rate (OR, 95% CI, P: 1.02, 1.01–1.04, 0.010), hemoglobin (Hb) (OR, 95% CI, P: 1.02, 1.01–1.04, 0.004), and AD (OR, 95% CI, P: 7.58, 1.68–34.20, 0.008) were found to be significant risk factors for the occurrence of postoperative oxygenation impairment (Table 1).