Relationship between serum level of thyroid hormones and plasma level of N-terminal Pro-brain natriuretic peptide in elderly patients with type 2 diabetes / 中华老年医学杂志

ABSTRACT

Objective To investigate the relationship between thyroid function indexes and plasma level of N-terminal pro-brain natriuretic peptide (NT-proBNP) among patients who had high risks for cardiovascular diseases without thyroid diseases and heart failure.Methods Totally 166 elderly type 2 diabetic patients aged 80 years and over with normal range of thyroid stimulating hormone (TSH) were divided into group of euthyroid sick syndrome (ESS,n=62) and group of normal thyroid hormones (NESS,n=104).The patients in normal thyroid hormones group were divided into three subgroups according to the levels of total triiodothyronine (TT3),(low-level group,n=26; middle-level group,n=50; high-level group,n=28).Levels of thyroid hormones,NT-proBNP,cholesterol,low-density lipoprotein cholesterol,fibrinogen,HbA1C,glomerular filtration rate (eGRF),left ventricular ejection fraction (LVEF) and the incidences of concomitant diseases were measured and detected.lgNT-proBNP was used to calculated after NT-proBNP was changed by Log transformation.Results Compared with NESS group,ESS group showed that age was increased,systolic pressure and LVEF were decreased [(86.3 ± 5.8) years vs.(85.6 ± 5.2) years,(126.6±15.5) mmHg vs.(135.6±17.8) mmHg,(63.9±7.6)％ vs.(67.4±7.5)％,all P＜0.01].Compared with NESS group,ESS group showed that the levels of serum total T3 and free T3 were decreased [(0.89±0.17) nmol/L vs.(1.45±0.31) nmol/L,(3.31±0.55) pmol/L vs.(3.96± 0.59) pmol/L,both P＜0.01].The lgNT-proBNP level was higher and serum total thyroxine (TT4) level was lower in ESS group than in NESS group [(2.40±0.40) ng/L vs.(2.26±0.44) ng/L,(101.80±36.11) nmol/L vs.(111.07±23.29) nmol/L,both P＜0.05].Pearson analysis revealed that serum levels of TT3,TT4 and FT3 were negatively correlated with lgNT-proBNP (r=-0.217,-0.180,-0.174,respectively,all P＜0.05) after adjustment for age,systolic pressure and LVEF.Stepwise regressive analysis showed TT3 was the risk factors for lgNT-proBNP (β=-0.267,P＜ 0.01).Compared with the low-level group,the lgNT-proBNP were significantly reduced in the middle-,and high-level groups [(2.19±0.42) ng/L,(2.19±0.46) ng/L vs.(2.44±0.39) ng/L,both P＜0.05].Conclusions TT3 has a close correlation with NT-proBNP in elderly type 2 diabetic patients with normal TSH.It has a significant meaning to test TT3 level for monitoring heart function in clinical medicine.