LCN2 and Cognitive impairment: Table 2 displays the correlation analysis between the serum NGAL level and MoCA score. From Q1 to Q4, MoCA scores were (25.8 ± 1.9), (24.9 ± 1.8), (24.2 ± 1.5) and (23.5 ± 1.6), respectively. The findings indicated that the MoCA score decreased as blood NGAL level increased (p < 0.001), indicating that a high serum NGAL level may be a sign of cognitive impairment.