Furthermore, when haptoglobin was categorized into quartiles and adjusted for various factors including age, sex, SBP, DBP, respiratory rate, temperature, WBC, platelets, glucose, bun, creatinine, sodium, potassium, chloride, ALT, AST, bilirubin, hypertension, diabetes, chronic pulmonary disease, APSIII and sofa score, a notable trend was observed (p for trend < 0.05), compared to the lowest serum haptoglobin level group (< 100 mg/dL), the risk of AKI in the highest serum haptoglobin level group (> 200 mg/dL) was reduced by 34.5 % (OR = 0.655, 95 % CI 0.439‒0.976, p = 0.038) (Table 3). This evidence concerns the gene HP and acute kidney injury.