Early detection of diabetic cardiomyopathy: usefulness of tissue Doppler imaging

Objective The aim of the study was to evaluate whether tissue Doppler imaging (TDI) detects a pre-clinical impairment of diastolic function in subjects with Type 2 diabetes with short duration of disease and normal cardiac function with conventional echocardiography (CE), and whether echocardiographic parameters are related to metabolic abnormalities. Patients and methods We studied 40 non-obese, normotensive, uncomplicated Type 2 diabetic subjects with short duration of disease and 20 control subjects. All participants underwent both CE and TDI echocardiography. With TDI, early velocity (Ea), atrial velocity (Aa), their ratio (Ea/Aa) and systolic velocity (Sa) were measured at the lateral corner of mitral annulus. Glycosylated haemoglobin, fasting plasma glucose and insulin were determined and homeostasis model assessment (HOMA-IR), as an index of insulin resistance, was calculated. Results Cardiac function with CE was similar in the two groups. Using TDI, diabetic subjects showed a lower Ea velocity (15.5 ± 3.9 vs. 19.4 ± 3.5 cm/s, P < 0.0001), an increased Aa velocity (15.5 ± 2.4 vs. 14.1 ± 2.4 cm/s, P < 0.05) and a reduced Ea/Aa ratio (1.00 ± 0.2 vs. 1.39 ± 0.3, P < 0.0001), compared with control subjects. Linear regression analysis in the diabetic group showed that only HOMA-IR was negatively associated with Ea/Aa ratio ( P = 0.026). No significant association was observed with other metabolic variables. Conclusion An early stage of diabetic cardiomyopathy can be evidenced by TDI in Type 2 diabetic subjects even in the presence of a normal cardiac function with CE. This abnormality is associated with insulin resistance. Diabet. Med. 22, 1720–1725 (2005)