Analysis Of The Correlation Between Low T3Syndrome And Heart Failure

Introduction：Heart failure is a common clinical refractory category ofdisease and prognosis is poorer. Over the years, the etiology, pathogenesis andclinical diagnosis and treatment of heart failure have been the focus of thestudy of scholars at home and abroad. In recent years, some scholars’ studieshave found that patients with heart failure are abnormal thyroid hormone level.A number of studies show that most associated with low T3syndrome inpatients with heart failure, and is closely related to the severity of heart failure.So researching the relations between the two, improving the quality ofsurvival in patients with heart failure and improving prognosis have importantclinical significance. In patients with heart failure with low T3syndrome, onthe basis of conventional treatment for thyroid hormone analogue tosupplement or alternative treatment, cardiac function can be improved and itcan be of benefit in patients with heart failure, it provides a new treatment forheart failure.Objective：To study the relationship between serum thyroid hormonelevels and the severity of heart failure.Methods：Serum thyroid hormone levels of55inpatients diagnosed asheart failure which were classified according to NYHA classification and45normal controls were examined. Automatic chemiluminescence method wasused to determine serum thyroid hormone level. Cardiac function of patientswith heart failure who were treated after anti-heart failure treatment were improved by at least one level and then thyroid hormone levels weremeasured again.Compared the differences of serum thyroid hormone betweenpatients with heart failure and normal controls, between different levels ofcardiac function,between different diseases,anti-heart failure before and aftertreatment.Analysis the correlation between thyroid hormone levels beforetreatment and cardiac function.Statistical analysis was performed bySPSS17.0software.Level for statistical difference was p<0.05.Results：1. The serum T3and FT3levels of heart failure group were lower thancontrol group(1.34±0.31ng/ml vs0.48±0.16ng/ml， P<0.01；3.25±0.70pg/ml vs1.23±0.46pg/ml，P<0.01） and the serum T4、FT4and TSHlevels had no difference compared with the control group（94.51±21.09μg/lvs93.86±19.43μg/l，P>0.05；1.34±0.22ng/dl vs1.33±0.19ng/dl，P>0.05；2.15±0.92μIU/ml vs2.18±1.07μIU/ml，P>0.05）.2.Levels of T3and FT3between NYHA II and III,NYHA III and IV hadno differences（0.69±0.06ng/ml vs0.50±0.05ng/ml，P>0.05；0.50±0.05ng/ml vs0.30±0.06ng/ml，P>0.05；1.80±0.10pg/ml vs1.30±0.16pg/ml，P>0.05；1.30±0.16pg/ml vs0.67±0.16pg/ml，P>0.05）.But levels of T3andFT3between NYHA II and IV had significant difference（s0.69±0.06ng/ml vs0.30±0.06ng/ml，P<0.05；1.80±0.10pg/ml vs0.67±0.16pg/ml，P<0.05）,andthe levels decrease with the elevated of NYHA classification.T4、FT4、TSHhad no significant difference between different levels of cardiac function（96.33±23.78μg/l vs93.95±16.07μg/l vs93.47±20.07μg/l， P>0.05；1.34±0.21ng/dl vs1.33±0.18ng/dl vs1.59±1.33ng/dl， P>0.05；2.29±1.10μIU/ml vs2.19±1.22μIU/ml vs2.14±1.03μIU/ml，P>0.05）.3. Patients with heart failure in the same classification which caused by different diseases had no difference in serum thyroxine（0.49±0.16ng/ml vs0.46±0.17ng/ml vs0.47±0.18ng/ml vs0.48±0.21ng/ml vs0.49±0.22ng/ml,P>0.05；1.27±0.44pg/ml vs1.22±0.53pg/ml vs1.19±0.49pg/ml vs1.22±0.63pg/ml vs1.24±0.64pg/ml, P>0.05；94.22±22.27μg/l vs93.12±24.78μg/l vs93.21±20.59μg/l vs94.69±19.64μg/l vs95.07±18.63μg/l，P>0.05；1.33±0.22ng/dl vs1.33±0.25ng/dl vs1.32±0.19ng/dl vs1.34±0.20ng/dl vs1.32±0.16ng/dl，P>0.05；2.16±1.27μIU/ml vs2.19±1.36μIU/ml vs2.18±1.01μIU/ml vs2.20±1.34μIU/ml vs2.20±1.05μIU/ml，P>0.05）.4. T3, FT3levels of patients with heart failure who were after treatmenthad apparent recovery with the improvement of cardiac function（0.48±0.16ng/ml vs0.72±0.47ng/ml， P<0.01；1.23±0.46pg/ml vs1.97±0.82pg/ml，P<0.01）.but there was no apparent differences in T4、FT4and TSH levels （93.86±19.43μg/l vs94.91±19.17μg/l， P>0.05；1.33±0.19ng/dl vs1.34±0.18ng/dl， P>0.05；2.18±1.07μIU/ml vs2.17±1.15μIU/ml，P>0.05）.5.There was a significantly negative correlation between levels of T3、FT3and severity of heart failure（r=-0.837，P<0.01；r=-0.942，P<0.01）.FT3has a stronger correlation between the severity of heart failure.But T4、FT4and TSH had no correlations with the severity of cardiac function（r=-0.406，P>0.05；r=-0.182，P>0.05；r=0.192，P>0.05）.Conclusion：1.Thyroid hormone metabolic disorders which exist in patients withchronic heart failure manifested as levels of T3、FT3decreased significantly,and decreased with the increase levels of cardiac function,while there was noapparent changes in levels of T4、 FT4, TSH. 2.Thyroid hormone levels(mainly T3and FT3) changed significantlybefore and after the treatment of heart failure.3.There was no relationship between changes of levels of thyroidhormone and causes of heart failure.4.Levels of T3、FT3was apparently negative correlation with theseverity of heart failure.5.Changes of levels of T3、FT3can seem as an important reference indexwhich may indicate the severity and prognosis value of heart failure andprovide a reference for the clinical assessment of heart failure.