The multiple linear regression analysis (showed in Table 4) confirmed the association between PPIs and elevated serum concentrations of free and total IS, free and total PCG, and PAG, even after adjustment for age, sex, the total number of co-prescribed medications, a history of AKI, serum CRP and albumin levels, diabetes, BMI, smoking status, urine albumin-to-creatinine ratio or protein-to-creatinine ratio (ACR), and eGFR. Here, ALB is linked to acute kidney injury.