To investigate the value of serum cardiac troponin I (cTnI) in the diagnosis and treatment of patients with type 2 diabetes mellitus and coronary heart disease (CHD).

A total of 122 patients with type 2 diabetes mellitus admitted to the Xiaoshan Hospital of Zhejiang from January 2017 to June 2019 were enrolled and divided into a diabetes mellitus group (54 cases) and a diabetes mellitus combined with CHD group (68 cases) according to the coronary arteriography; 50 healthy people during the same period in our hospital were selected as the healthy control group. Hemoglobin A1c (HbA1c), creatine kinase-MB (CK-MB) and cTnI were tested and compared among the three groups. The correlation between markers of myocardial injury (CK-MB, cTnI) and the degree of coronary artery disease (Gensini score) was analyzed by Pearson correlation analysis. The receiver operating characteristic (ROC) curve was used to assess the value of CK-MB and cTnI for predicting whether patients with type 2 diabetes mellitus have CHD.

The levels of HbA1c, CK-MB and cTnI all showed significant differences among 3 groups (F = 26.820, 14.011, 93.287; all P<0.05). Further pairwise comparison showed that the levels of HbA1c [(6.5 ± 0.7)%, (6.7 ± 0.9)%, (5.8 ± 0.5)%], CK-MB [(21 ± 6), (23 ± 7), (17 ± 4) U/L] and cTnI [(22 ± 6), (28 ± 7), (13 ± 4) ng/L] in the diabetes mellitus group and diabetes mellitus combined with CHD group were much higher than those in the healthy control group, and the levels of HbA1c and cTnI were highest in the diabetes mellitus combined with CHD group (all P<0.05). Meanwhile, the cTnI was positively correlated with Gensini score (r = 0.547, P<0.001), but there was no correlation between CK-MB and Gensini score (r = 0.059, P>0.05) in the patients with type 2 diabetes mellitus and CHD. The ROC curve showed that cTnI was valuable for predicting whether patients with type 2 diabetes mellitus have CHD, and the area under the curve was 0.765. With the optimal cTnI cut-off point > 23.5 ng/L, the sensitivity and specificity were 72.1% and 70.4%, respectively.

Serum cTnI isclinically valuable for predicting whether patients with type 2 diabetes mellitus have CHD, which is often in a low level or slight increase.