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.


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.


CONCLUSIONS
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.
Di Bonito
P
P
Department of Internal Medicine,Cardiology S. Maria delle Grazie Pozzuoli Hospital, Naples, Italy. procolodibonito@libero.it
Moio
N
N
Cavuto
L
L
Covino
G
G
Murena
E
E
Scilla
C
C
Turco
S
S
Capaldo
B
B
Sibilio
G
G
D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D009202:Cardiomyopathies / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000503:physiopathology*; D003925:Diabetic Angiopathies / Q000000981:diagnostic imaging* / Q000503:physiopathology; D042241:Early Diagnosis; D015150:Echocardiography, Doppler / Q000592:standards; D005260:Female; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D008875:Middle Aged; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology