COMPARISON OF ECHOCARDIOGRAPHIC VARIABLES BETWEEN TYPE-I DIABETICS AND NORMAL CONTROLS

This report compares echocardiographic estimates of systolic and diast olic function and ventricular dimensions in type I diabetics and norma l controls. A random sample of 60 diabetics selected from a central ho spital diabetic clinic was compared with a sample of 40 nondiabetic co ntrols, and matched to the diabetics by age, gender, and blood pressur e. Simple comparisons showed that diabetics had a higher mean resting heart rate (HR) (p < 0.001) and a slower diastolic early filling phase (maximal rate of increase in left ventricular dimension in early dias tole [dv/dtmax], p = 0.08; time from end-systole until dv/dtmax [ES-dv /dtmax], p 0.03), which were explained by differences in HR and other factors. Resting HR was significantly associated with several echocard iographic variables, but the slope relating resting HR to ventricular dimension was more negative in diabetics than in controls (end-diastol ic diameter, p < 0.008; end-systolic diameter, p < 0.005), and the rat io of systolic to diastolic duration was significantly (p < 0.01) less positive in diabetics. The association of resting HR to duration of i sovolumic diastole was positive in diabetics and negative in controls (p < 0.02). Among diabetics, those with higher resting HR had more ret inopathy (p < 0.05), microalbuminuria (p < 0.05), smaller ventricles ( p < 0.01), and longer isovolumic diastole (p < 0.05). Poorer diabetic control was associated with poorer systolic (fractional shortening, p < 0.05) and diastolic (dv/dtmax, p < 0.05; ES-dv/ dtmax, p < 0.05) fun ction. Longer duration of diabetes (adjusted for age) was associated w ith more retinopathy (p < 0.01) and microalbuminuria (p < 0.01), but t here were no clear differences in cardiac function. Thus, resting HR, duration of diabetes, and adequacy of control predict complications in diabetics.