LPA and acute kidney injury: To analyse the association between the prevalence of CI-AKI and the serum Lp(a) level or ApoB/ApoA-Ι ratio, we divided patients into Lp(a) quartiles and calculated the odds ratios (ORs) of their risk of CI-AKI, taking patients in the first Lp(a) quartiles as a reference (Table 2).