Correlation Between Thyroid Hormone Levels And Cognitive Function In Parkinson’s Disease

Objective:To compare the difference of thyroid function between patients with Parkinson’s disease with thyroid hormone(PDD)and those without thyroid hormone(nPDD),and to explore the relationship between thyroid hormone level and course of disease,H-Y grade,UPDRS-Ⅲ score,LEDD and different cognitive domains.It is important to pay attention to the thyroid function of PD patients and give corresponding intervention measures for the prognosis of the disease.This study provides a basis for the correlation between the level of thyroid hormone and the cognitive function of PD.Methods:88 Parkinson’s disease patients who visited the Neurology Department of the First Hospital of Shanxi Medical University from April 2021 to January 2023 were collected and divided into PDD group(n=38)and nPDD group(n=50)based on MMSE scores.All participants completed the Unified Parkinson’s Disease Rating Scale Part Ⅲ(UPDRS-Ⅲ)score,Hoehn Yahr(H-Y)grading,levodopa equivalent daily dose(LEED),Simplified Mental State Examination Scale(MMSE)Evaluation of the Montreal Cognitive Assessment Scale(MOCA,Beijing version),Assessment of Daily Living Ability(ADL),Hamilton Anxiety Scale(HAMA),Hamilton Depression Scale(HAMD),and measurement of thyroid function related indicators.The differences of general clinical data and thyroid hormone levels between the two groups were compared,and the correlation between thyroid hormone levels and clinical data and different cognitive domains was analyzed.Statistical analysis was conducted on the subjects using SPSS26.0 software,and the difference was statistically significant when P<0.05.Results:Compared with the nPDD group,patients in the PDD group had higher UPDRS-Ⅲ scores,higher levodopa equivalent daily dose(LEDD),shorter education years,and higher scores on ADL,HAMA,and HAMD compared to the nPDD group,with statistically significant differences(P<0.05);There was no significant difference in TSH,FT3,and FT4 levels betweenPDD patients and nPDD patients(P>0.05).The TSH level is positively correlated with gender(r=0.294,P<0.01),and negatively correlated with HAMA score(r=-0.246,P<0.05),with statistical significance;The FT3 level is negatively correlated with age(r=-0.293,P<0.01)and gender(r=-0.320,P<0.01),with statistical significance;There was no correlation between FT4 and clinical data such as age and gender(P>0.05).TSH,FT3,FT4 were not correlated with the course of disease,H-Y grading,UPDRS-Ⅲ score,and LEDD of PD(P>0.05).FT3 is positively correlated with visual space and executive function(r=0.630,P<0.01),delayed memory(r=0.307,P<0.05),and language(r=0.222,P<0.05),with statistical significance.After removing confounding factors,FT3 levels were positively correlated with visual space and executive function(P<0.01).Conclusions:PDD patients have shorter educational years,more severe symptoms,and a higher equivalent daily dose of levodopa compared to nPDD patients;Compared with nPDD patients,PDD patients have poorer daily living abilities and higher levels of anxiety and depression.There was no significant difference in TSH,FT3,and FT4 levels betweenPDD patients and nPDD patients.Lower FT3 levels are associated with poorer cognitive function,especially in terms of visual space and executive function.