Association Of Serum TSH Level And Coronary Artery Disease Severity In Normal Thyroid Function

Objective:To investigate the correlation between serum thyroid stimulating hormone(TSH)level and the severity of coronary artery lesions in patients with coronary artery disease!CAD" with normal thyroid function.MethodWe enrolled 895 patients with suspected CAD and normal thyroid function who were admitted to Fuwai Hua Central Cardiovascular Hospital in Henan Province from January 2020 to December 2021.Each participant underwent coronary angiography.General clinical data of the subjects were collected,namely gender,age,body mass index(BMI),history of hypertension,diabetes,smoking,alcohol consumption.Blood samples were tested four items of blood lipids,three items of thyroid function,and Glycosylated Hemoglobin Type A1C(Hb A1c).According to the Diagnostic Guidelines for Coronary Heart Disease formulated by the National Health Commission in 2019,the subjects were divided into coronary artery disease group and noncoronary artery disease group.According to Gensini scores,the subjects were divided into G1 group(0<score ≤30),G2 group(30< score ≤60),and G3 group(60< score).According to the number of major vascular lesions with stenosis rate greater than 50%,the study subjects were divided into normal control group(number of lesion =0),minor lesion group(number of lesion =1),and moderate lesion group(number of lesions =2).Severe lesion group(number of lesions #3).TSH levels in the normal range were divided into three groups according to P25 and P75 demarcation point: low-normal TSH group(0.27 m IU/L≤ TSH≤1.31 m IU/L),middle-normal TSH group(1.31 m IU/L< TSH ≤2.50 m IU/L),high-normal TSH group(2.50 m IU/L< TSH ≤4.20 m IU/L).Independent samples t-test was used to analyze the correlation between the occurrence of coronary heart disease and TSH level.The relationship between coronary lesion degree and TSH level was evaluated by One-way ANOVA.Multiple Logistic regression analysis was used to evaluate the risk factors for the severity of coronary artery disease.Result1.Compared with the non-coronary artery disease group,the proportion of males and the proportion of hyperlipidemia in the coronary artery disease group were significantly higher [(60.2% vs 69.2%,χ2=5.68,P=0.017)$(48.3% vs 56.3%,χ2=4.11,P=0.043)],and the difference was statistically significant.Compared with the non-coronary group,the HDL-C level in the coronary group was significantly decreased(1.09±0.30 vs 1.05±0.27,t=1.97,P=0.049),and the difference was statistically significant.The difference in TSH level between the two groups was not statistically significant(1.89±0.75 vs 2.00±0.88,t=-1.7,P=0.09).2.The Gensini scores of G1 group(n=437),G2 group(n=211)and G3 group(n=156)were(14.88±8.00),(43.75±8.43)and(96.53±27.92),respectively.Compared with G1 group,the proportion of hyperlipidemia and TSH level in G3 group were significantly increased [(49.7% vs 63.5%,P=0.003),(1.91±0.82 vs2.16±0.94,P=0.011)],and the difference was statistically significant.3.The TSH levels of control group,mild vessel lesion group,moderate vessel lesion group and severe vessel lesion group were(1.89±0.75)m IU/L,(1.84±0.85)m IU/L,(2.00±0.86)m IU/L,and(2.14±0.90)m IU/L,respectively.Compared with control group and mild vessel lesion group,TSH level in severe lesion group was significantly increased,the difference was statistically significant(P=0.010;P=0.002).There were statistically significant on Gensini score,age,proportion of hypertension,total cholesterol(TC)and lowdensity lipoprotein cholesterol(LDL-C)among different groups(P<0.05).4.The number of vessels lesions in low-normal TSH group,middle-normal TSH group and high-normal TSH group were(1.56±1.30),(1.56±1.26)and(2.04±1.44),respectively.The Gensini scores were [19.0(41.0)],[21.0(33.0)],[35.5(35.5)].Compared with low-norml TSH group and middle-normal TSH group,the number of vessel lesion in high-normal TSH group was significantly higher,the difference was statistically significant(P=0.001,P<0.0001);Gensini score also increased significantly,the difference was statistically significant(P<0.0001,P<0.0001).Gender,age,high-density lipoprotein cholesterol(HDL-C),free triiodothyronine(FT3),free thyroxine(FT4)among different groups were compared,and the differences were statistically significant(P<0.05).5.Multivariate logistic regression analysis showed that TSH level within the normal range was an independent risk factor for the severity of coronary artery disease.Taking mild lesions group as the reference category,TSH levels can cause whether mild or moderate lesions [OR: 1.273,95%CI:(1.014,1.597),P=0.037],the difference was statistically significant.The TSH level of severe vessel lesion group was 1.496 times as much as that of mild lesions group [OR: 1.496,95%CI:(1.205,1.856),P<0.0001],and the differences were statistically significant.The higher the TSH level,the more severe the coronary lesions.The analysis also revealed age and history of hypertension as significant predictors of vessel lesion severity(P<0.05).Conclusion1.TSH levels within the normal range are irrelevant with the presence of CAD.2.High-normal TSH may lead to increased severity and extent of coronary lesions.3.Men accompanied by low HDL-C are more likely to suffer from CAD.4.Patients with hyperlipidemia are more likely to develop CAD,and if patients with CAD are complicated with hyperlipidemia,the vessels lesions will be more serious.5.TSH level,old age and history of hypertension may be independent risk factors for the severity of coronary artery lesions.