TNNI3 and familial dilated cardiomyopathy: Evidence has shown that the serum glycosylated hemoglobin (HbA1c) and cardiac troponin I (cTnI) levels in the DCM group were significantly higher than those in the diabetes mellitus alone group, suggesting that serum HbA1c and cTnI levels were closely related to DCM and could serve as promising diagnostic markers for DCM [4, 5].