To investigate the correlation and clinical significance of serum lipocalin-2 level with cognitive impairment in patients with the stable stage of chronic obstructive pulmonary disease (COPD).

According to the Montreal cognitive assessment(MoCA)scale standard for evaluation, a cutoff score of <26 defined as mild cognitive impairment(MCI). A total of 43 patients in the stable stage of COPD were divided into a cognitive impairment group(Cog I) (23 patients)and a cognitive normal group (Cog N)(20 patients), and 20 healthy Subjects as control group. The level of serum lipocalin-2 in each group was detected by enzyme-linked immunosorbent assay (ELISA), the correlation between lipocalin-2 and cognitive function was analyzed, and the ROC curve of cognitive impairment was predicted according to the level of lipocalin-2.

Compared with the healthy control group(60.37±10.77)μg/ml, the serum level of lipocalin-2 in stable COPD patients with cognitive impairment (82.76±12.90) μg/ml was significant higher(P<0.05). Compared with than the cognitive normal group (69.70±11.51)μg/ml, the protein level of lipocalin-2 was increased in serum of stable COPD patients with cognitive impairment(P<0.05). Pearson line correlation revealed that the serum level of lipocalin-2 was negatively correlated with MoCA score (r=-0.749, P<0.001), The areas under ROC curve of serum lipocalin-2 level to predict cognitive dysfunction in the COPD patients was 0.804 (95%CI 0.664-0.945, P<0.001).

The serum lipocalin-2 level is closely related to the cognitive dysfunction of stable COPD patients. The detection of serum lipocalin-2 level may be an important diagnostic index of cognitive dysfunction in COPD patients.