Subclinical left ventricular dysfunction in asymptomatic patients with Type II diabetes mellitus, related to serum lipids and glycated haemoglobin

Abstract

The aim of the present study was to measure regional ventricular function at rest and during stress in order to assess if patients with Type II diabetes have subclinical myocardial dysfunction and if it is related to risk factors. Seventy subjects (35 patients with Type II diabetes with no symptoms, signs or history of heart disease, and 35 age- and sex-matched healthy controls) had echocardiography at rest and during dobutamine stress. Myocardial velocities were measured off-line from digital loops of colour tissue Doppler. Subendocardial function was assessed from the mean longitudinal velocities of four basal segments (apical views) and radial function from the velocities of the basal posterior wall (parasternal view). Systolic functional reserve was calculated as the increase in velocity from baseline. Longitudinal peak systolic velocity was lower in patients with diabetes, at rest (5.6±1.4 compared with 6.5±1.1 cm/s) and at peak stress (10.9±2.8 compared with 14.3±2.1 cm/s) (both P<0.01). Functional reserve was impaired in patients with diabetes (+5.4±2.0 compared with +7.7±1.7 cm/s; P<0.01). Radial systolic velocity was higher in patients with diabetes (5.4±1.3 compared with 4.7±1.4 cm/s; P<0.05). Resting longitudinal systolic function correlated inversely with low-density lipoprotein—cholesterol (r=-0.53), glycated haemoglobin (r=-0.48), age (r=-0.41) and diastolic blood pressure (r=-0.38) (all P<0.05). Peak stress systolic velocity correlated inversely with glycated haemoglobin (r=-0.46) and age (r=-0.44) (both P<0.01). In conclusion, patients with Type II diabetes and no clinical heart disease have impaired subendocardial function of the left ventricle at rest and peak stress, which is related to glycated haemoglobin and serum low-density lipoprotein—cholesterol.