RÉSUMÉ
Objective To explore the relationship between the levels of serum dopamine,5-hydroxytryptamine,homovanillic acid and cognitive dysfunction in patients with Parkinson's disease.Methods A total of 118 Parkinson's disease patients admitted to Bazhong Central Hospital from February 2020 to February 2022 were selected as the disease group,and 106 healthy patients who underwent physical examination in the hospital during the same period were selected as the control group.The levels of serum do-pamine,5-hydroxytryptamine and homovanillic acid were measured in all subjects,and the cognitive function was evaluated with Montreal Cognitive Assessment Scale(MoCA).Parkinson's disease patients were divided into cognitive impairment group and non cognitive impairment group according to MoCA score.The serum do-pamine,5-hydroxytryptamine,homovanillic acid levels of the cognitive impairment group and the non cogni-tive impairment group were compared.Pearson correlation analysis was used to analyze the correlation be-tween serum dopamine,5-hydroxytryptamine and homovanillic acid levels and cognitive function of Parkinson's disease patients,and the receiver operating characteristic curve was drawn to analyze the evaluation value of serum dopamine,5-hydroxytryptamine and homovanillic acid levels on cognitive dysfunction of Parkinson's disease patients.Results The levels of serum dopamine,5-hydroxytryptamine,homovanillic acid and MoCA score in the disease group were lower than those in the control group,with statistical significance(P＜0.05).The levels of serum dopamine,5-hydroxytryptamine,homovanillic acid and MoCA score in advanced patients were lower than those in early patients,and the difference was statistically significant(P＜0.05).The levels of serum dopamine,serotonin and homovanillic acid in the cognitive dysfunction group were lower than those in the non-cognitive dysfunction group,and the difference was statistically significant(P＜0.05).The results of Pearson analysis showed that the levels of serum dopamine,5-hydroxytryptamine and homovanillic acid in Parkinson's disease patients were positively correlated with MoCA score(P＜0.05).The sensitivity of the combined assessment of serum dopamine,serotonin and homovanillic acid in Parkinson's disease patients was higher than that in Parkinson's disease patients alone(x2=7.413,P=0.006;x2=9.714,P=0.002;x2=8.541,P=0.003),the area under the curve(AUC)was higher than the AUC for assessing cognitive impair-ment in Parkinson's disease alone(Z=2.479,P=0.013;Z=2.271,P=0.023;Z=2.451,P=0.014).Conclusion There are differences in serum levels of dopamine,5-hydroxytryptamine,homovanillic acid and cognitive function among different stages of Parkinson's disease patients.Serum levels of dopamine,5-hydroxytryptamine,and homovanillic acid are closely related to cognitive function in Parkinson's disease pa-tients,all of which have evaluation value for the occurrence of cognitive dysfunction in Parkinson's disease pa-tients.However,the combination of the three serum indicators is more helpful for clinical evaluation and diag-nosis.