Objective: To test the hypothesis that quantitative analysis of two-dimensional echocardiographic gray-level distributions could allow one to detect the early changes in acoustic properties of human diabetes myocardium differentiating it from normal myocardium.
Methods: We evaluated, by two-dimensional echocardiography, 28 asymptomatic type 1 insulin-dependent diabetic patients with normal ventricular function (group A) and 15 age- and sex-matched healthy controls (group B). By selection, all of the diabetics were normotensive and had a negative maximal exercise stress. Echocardiographic images were digitized by using a calibrated digitization system. Quantitative texture analysis was accomplished on data from the septum and posterior wall both at end-diastole and at end-systole. The following parameters were obtained: the mean gray level of the regions of interest, and its absolute SD, skewness, kurtosis, and cyclic variation index.
Results: The main result of this study was that the cyclic variation indices of the echo amplitudes of the septum and posterior wall in the diabetic group were significantly lower than those in controls (P < 0.001 and P < 0.002, respectively). Furthermore, the diabetic group had a significantly higher mean gray level of the septum [group A 54.3 +/- 22.5 (mean +/- SD) versus group B 39.7 +/- 9.8, P < 0.03] at end-diastole. The mean gray-level of the posterior wall was similar in the two groups, both at end-diastole and at end-systole.
Conclusion: Alterations of cyclic echo amplitude (possibly related to collagen deposition) can be detected in asymptomatic diabetic patients with normal resting function. Theoretically, this finding might be considered an early preclinical alteration, potentially related to subsequent development of "diabetic cardiomyopathy'.