Isolated and preclinical impairment of left ventricular filling in insulin-dependent and non-insulin-dependent diabetic patients

Background: Diabetes mellitus can induce a pattern of myocardial pathology known as specific diabetic cardiomyopathy, even if this is not clearly specified. Hypothesis: The aim of our study was to evaluate the presence of preclinical myocardial damage in insulin- and non-insulin- dependent diabetic patients and controls by assessment with Doppler echocardiography. Methods: Twenty insulin-dependent diabetic (IDDM) patients, 10 non-insulin-dependent diabetic (NIDDM) patients, and 12 healthy individuals (C) as controls, matched for age, gender, and without overt cardiovascular disease, were assessed in this study. Results: Systolic function parameters presented normal values in the three groups, with the exception of a slight reduction in ventricular volume indices in the NIDDM group. Diastolic function was clearly impaired in both groups of patients versus that in healthy controls. In particular, ventricular filling was impaired in the NIDDM compared with the IDDM patients, especially the peak early filling rate E (p<0.001). Moreover, in the IDDM group, the duration of diabetes (p<0.01) and glycosilated hemoglobin value (HbA1C, p<0.02) were higher than in the NIDDM group. Multiple regression analysis showed a significant inverse correlation between HbA1C and peak late filling rate A (R2 = 0.28) in both groups of patients and a direct correlation between velocity time integral E and age, duration of diabetes, and HbA1C (R2 = 0.46). The two groups presented a small, homogeneous number of cases with initial microangiopathy and borderline autonomic neuropathy, associated with microalbuminuria. Doppler echocardiography showed an early impairment of left ventricular filling, as well as an early preclinical alteration of myocardial function in diabetic patients, especially in the NIDDM group. Conclusion: These early signs of cardiomyopathy could constitute a predisposing condition toward the high cardiac morbidity and mortality rate in diabetic patients.