Objective:To explore the correlation between urine Alzheimer disease associated neuronal thread protein (AD7C-NTP) and cognitive dysfunction in patients with Parkinson disease (PD).Methods:The clinical data of 90 patients with PD in Weihai Central Hospital in Shandong Province from April 2016 to August 2019 were retrospectively analyzed. According to the Montreal cognitive assessment scale (MoCA) score, the patients were divided into non cognitive impairment group (46 cases) and mild cognitive impairment group (44 cases). Forty-five healthy persons matched in gender and age were selected as control group. The urine AD7C-NTP, and serum homocysteine (Hcy), uric acid, C-reactive protein (CRP) were detected. The MoCA score, PD Hoehn-Yahr classification (H-Y classification), levodopa equivalent dose and time of taking medicine were record. The correlation between AD7C-NTP and various clinical indicators was analyzed by Pearson method. Risk factors of cognitive dysfunction in patients with PD were analyzed by Logistic regression.Results:The AD7C-NTP and Hcy in mild cognitive impairment group were significantly higher than those in control group and non cognitive impairment group: (3.3 ± 2.3) μg/L vs. (1.9 ± 1.6) and (2.1 ± 2.0) μg/L, (13.5 ± 3.4) μmol/L vs. (9.1 ± 4.5) and (11.0 ± 3.1) μmol/L, the indexes in non cognitive impairment group were significantly higher than those in control group, and there were statistical differences ( P<0.05). The uric acid in mild cognitive impairment group was significantly lower than that in control group and non cognitive dysfunction group: (286.7 ± 62.9) μmol/L vs. (338.6 ± 70.4) and (322.9 ± 81.2) μmol/L, the index in non cognitive impairment group was significantly lower than that in control group, and there were statistical differences ( P<0.05). The MoCA score in mild cognitive impairment group was significantly lower than that in non cognitive impairment group: (22.9 ± 2.9) scores vs. (27.3 ± 2.4) scores, the H-Y classification, levodopa equivalent dose and time of taking medicine were significantly higher than those in non cognitive impairment group: (2.7 ± 0.7) stages vs. (2.4 ± 0.6) stages, (465.8 ± 132.1) mg/d vs. (405.8 ± 139.5) mg/d and (46.9 ± 22.1) months vs. (35.8 ± 24.4) months, and there were statistical differences ( P < 0.01 or<0.05). Pearson correlation analysis result showed that AD7C-NTP was negatively correlated with uric acid and MoCA scores ( r = -0.365 and -0.586, P < 0.01), and positively correlated with H-Y classification, levodopa equivalent, Hcy and time of taking medicine ( r = 0.568, 0.434, 0.362 and 0.324; P < 0.01). Multivariate Logistic regression analysis result showed that AD7C-NTP, Hcy and H-Y classification were independent risk factors of cognitive dysfunction in patients with PD ( P < 0.01 or<0.05), and uric acid was an independent protective factor ( P < 0.05). Conclusions:The expression of urine AD7C-NTP is increased in PD patients with cognitive impairment. The level of urine AD7C-NTP is correlated with cognitive impairment and disease severity, which may be an effective biomarker of cognitive impairment in PD patients.