Effect of age on the association between normal thyroid hormone level and coronary artery disease / 中华老年医学杂志

ABSTRACT

Objective To investigate the effect of age on the association between normal thyroid hormone level and coronary artery disease (CAD).Methods A total of 1163 euthyroid patients undergoing coronary angiography (CAG) from January 2013 to June 2014 were enrolled and categorized into 2 groupsthe young and middle-aged group (＜60 years,n=602) and the elderly group (≥60 years,n=561),and each group was sub grouped into the CAD and non-CAD group according to CAG.Height,body weight,and levels of serum lipid,fasting blood glucose,glycosylated hemoglobin,free triiodothyronine (FT3),free thyroxine (FT4) and thyroid-stimulating hormone (TSH) were measured.Results In the youth and middle-aged group,309 patients (51.3％) were diagnosed as CAD,and there was no significant difference in the levels of FT3,FT4 and TSH between CAD and non-CAD patients [(5.3±0.6)mmol/L vs.(5.3±0.5)mmol/L,(11.8 ±1.9)mmol/L vs.(11.8±1.8) mmol/L,(2.0±1.1) mIU/L vs.(2.0±1.0)mIU/L,all P＞0.05].In the elderly group,357 patients (63.6％) were diagnosed as CAD,and the FT3 level was lower in the CAD patients than in the non-CAD patients[(5.1±0.6)mmol/L vs.(5.2±0.5) mmol/L,P＜0.01].Logistic regression demonstrated that FT3 was an independent influencing factor for CAD in elderly patients (OR=0.564,P＜0.01).Conclusions The association between normal thyroid hormones levels and CAD varies along with age.Thyroid hormones have no relationships with CAD in the young and middle-aged people.The decline of FT3 level may increase the risk of CAD in the elderly.