Abnormalities suggestive of cardiomyopathy in patients with type 2 diabetes of relatively short duration.

Abstract

Objective: The aim was to assess the presence of cardiomyopathic features in asymptomatic patients with Type 1 and Type 2 diabetes mellitus.

Research design and methods: Fifty-two (27 Type 1; mean duration: 10.2 +/- 7.4 yr; 25 Type 2, mean duration: 6.5 +/- 4.4 yr) diabetic patients with no signs of ischaemic heart disease or high blood pressure were studied by noninvasive techniques: Holter ECG; Filtered-Amplified ECG (FAECG); Exercise ECG; Echocardiography (BD, TM) and Doppler evaluation of diastolic parameters. Twenty-four healthy subjects matched for age were studied as controls.

Results: Holter ECG did not detect rhythm disturbances or features of silent ischaemia in either group of patients. With FAECG, at least one criterion of late ventricular potentials was found in 28% of Type 2 patients, vs 11% of Type 1 patients and 8.3% of control subjects. With exercise ECG, maximum oxygen uptake, anaerobic threshold, and workload performance were all significantly lower in Type 2 patients compared to control subjects. Echocardiography depicted a greater end diastolic interventricular septum thickness in Type 2 patients than in control subjects, with a trend toward left ventricular hypertrophy in 28% of Type 2 and 7.4% of Type 1 patients. Doppler echocardiography revealed a significant decrease in early diastolic peak filling rates (E) in diabetic patients as a whole group (Type 1 + Type 2) compared to controls. Late diastolic peak filling rates (A) were significantly higher in Type 2 patients than in their controls. The E/A ratio was significantly lower in diabetic patients (as a whole group) than in control subjects; this was accounted for mainly by a significant decrease of E/A in Type 2 patients compared to their controls.

Conclusions: Our major finding rests on the disclosure of abnormalities suggestive of cardiomyopathy in Type 2 diabetic patients with a relatively short duration of the known disease, while these alterations appeared in our study less prominent in Type 1 patients despite a longer duration of the disease. Among the various noninvasive techniques, FAECG and Doppler echocardiography used to detect late ventricular potentials and to assess left ventricular diastolic dysfunction, respectively, appear to be suitable tools.