Association of low levels of free thyroxin within normal range with the severity of coronary artery disease and carotid atherosclerosis / 西安交通大学学报(医学版)

ABSTRACT

Objective To investigate the association of low level of free thyroxin (FT4)within normal range with the severity of coronary artery disease (CAD)and carotid atherosclerosis.Methods We enrolled 312 consecutive patients who underwent coronary angiography (CAG)and divided them into CAD group (196 cases)and non-CAD group (116 cases)according to CAG results.We calculated Gensini score and divided CAD group into≤10 Gensini score group (n=65),10-30 Gensini score group (n=67)and ＞30 Gensini score group (n=64).Thyroid hormone level,carotid intima-media thickness (CIMT)and other clinical data were measured and compared between the groups,and the correlation analysis was used to find the relationship of FT4 level with Gensini score.By taking CIMT reference value of 0.9 mm as the standard,we divided the patients into thickened IMT group (IMT≥0.9 mm)and normal IMT group (IMT＜0.9 mm).Results The level of FT4 was significantly lower in CAD group and subgroups than in non-CAD group (P＜0.05).The level of FT4 was negatively correlated with Gensini score (P＜0.05).The levels of FT4 and TT4 were significantly lower in thickened CIMT group than in normal CIMT group (P＜0.05).Conclusion Low level of FT4 within normal range is significantly related to the severity of CAD,and low level of FT4 can be used as an independent risk factor for the severity of CAD.Low levels of FT4 and TT4 are significantly related to carotid atherosclerosis.