Correlation Between Serum Thyrotropin Levels And Coronary Lesions In Patients With Subclinical Hypothyroidism

Objective:In recent years,coronary atherosclerotic heart disease(CHD)has become one of the major diseases threatening human health.The cause of coronary heart disease has not been fully determined,and the "traditional risk factors" of coronary heart disease have been reported to include patients with age,sex,obesity,smoking,hypertension,diabetes and family history.With the development of evidence-based medicine,people have a new understanding of the risk factors of coronary heart disease,blood lipid related components,metabolic related factors,inflammatory related factors,gene polymorphism,genetic factors and social and psychological factors are called coronary heart disease "new risk factors" [1].Among them,dyslipidemia is the most important factor.Studies[2-4] found that subclinical hypothyroidism(SCH)can affect blood lipid metabolism in patients,leading to dyslipidemia,which significantly increases the incidence of atherosclerosis and becomes an independent risk factor for coronary atherosclerosis.At present,the single lipid index cannot completely predict and explain the pathogenesis and outcome of cardiovascular events,and the comprehensive lipid index has become a new hot spot in the study of cardiovascular disease.Studies[5] have confirmed that the critical degree of CHD is positively correlated with coronary lesions,and the severity of coronary lesions can be evaluated by calculating the SYNTAX score in clinical work.The aim of this study was to investigate the association of serum thyrotropin(TSH)levels with SYNTAX scores in patients with coronary heart disease combined with subclinical hypothyroidism,thus exploring the relationship between TSH levels and the severity of coronary lesions.Methods:To collect 246 patients first diagnosed with coronary heart disease by coronary angiography(CAG)in Baoding first central hospital from October 2016 to October 2018 due to chest tightness,chest pain and other discomfort in the precardiac area,according to the level of serum TSH,it was divided into 126 cases in subclinical hypothyroidism group(TSH>4.5m IU/L)and 120 cases in normal group(TSH 0.45～4.5m IU/L),and recorded the results of coronary angiography.The SYNTAX score of coronary lesions in the subclinical hypothyroidism group was divided into 67 cases with low group(0～22),27 cases with middle group(23～32)and 32 cases with high group(≥33).Collect general information of patients after admission including age,sex,smoking,drinking,hypertension,diabetes,systolic blood pressure,diastolic blood pressure,body mass index(BMI)were calculated.Record the patient’s venous blood on an empty stomach for at least 8 hours the next morning of admission the thyroid hormone levels(TSH、FT3、FT4、TT3、TT4)were measured by cobas8000 roche electrochemiluminescence instrument in germany,the blood lipid index(TC、TG、HDL-C、LDL-C、Apo A1、Apo B、AIP[6]),UA,Cr,BUN,GLU,PLT,D-Dimer,FIB were tested by a japanese hitachi Hitachi7600 automatic biochemical analyzer.Spearman was used to analyze the correlation between SYNTAX scores and TSH,FT3,FT4,TT3,TT4,TC,TG,HDL-C,LDL-C,AIP.Note: BMI=[body weight(kg)divided by height(m)squared],AIP=[ log TG/HDL-C].Results: 1 Comparison of basic data between subclinical hypothyroidism group and normal groupThere was no significant difference in age,sex,smoking history,drinking history,hypertension prevalence,diabetes prevalence,BMI,systolic blood pressure and diastolic blood pressure in the two groups(P>0.05).2 Comparison of biochemical indexes between subclinical hypothyroidism group and normal groupThe TSH,TC,TG,LDL-C,AIP in the subclinical hypothyroidism group were all higher than those in the normal group,the difference was statistically significant(P<0.05);at the FT4 level,the subclinical hypothyroidism group was lower than the normal group,the difference was statistically significant(P<0.05).3 Comparison of SYNTAX scores and biochemical indexes in subclinical hypothyroidism groupThe differences in TSH,FT3,TT3,TC,TG,LDL-C and AIP were statistically significant in SYNTAX scores of subclinical hypothyroidism group.Among them the high group TSH,TC,TG,LDL-C,AIP was higher than the middle group and low group,the middle group was higher than the low group,the difference was statistically significant(P<0.05);at the FT3 level,the high group was lower than the middle group And the low group,the difference was statistically significant(P<0.05);at the TT3 level,the high group was lower than the low group,and the difference was statistically significant(P<0.05).4 Correlation analysis between SYNTAX score and biochemical indexThe SYNTAX scores were positively correlated with TSH(r=0.768,P <0.001),TC(r=0.650,P<0.001),TG(r=0.581,P<0.001),LDL(r=0.594,P <0.001),AIP(r=0.481,P<0.001).The SYNTAX score was negatively correlated with FT3(r=-0.207,P=0.020),TT3(r=-0.270,P=0.002).Conclusion:Serum TSH of patients with coronary heart disease combined with subclinical hypothyroidism is positively correlated with severity of coronary artery disease,blood lipid disorder is more serious,and changes of coronary artery disease are complicated.