Silent myocardial ischaemia in patients with essential arterial hypertension and non-insulin dependent diabetes mellitus

The concomitant presence of diabetes mellitus and arterial hypertension sig nificantly impairs myocardial function through a direct negative effect on cardiac myocytes, coronary microvessels and precipitation of atherosclerosi s in major coronary arteries. The purpose of the present study was to estab lish to what extent non-insulin dependent diabetes mellitus (NIDDM) modifie d silent myocardial ischaemia (SMI) in patients with essential hypertension and without documented coronary artery disease (CAD). The study population consisted of 41 patients with essential arterial hyper tension associated with NIDDM, treated with diet and oral hypoglycaemic age nts (group I) and 40 patients with essential arterial hypertension without diabetes mellitus (group II). Both groups were comparable with respect to a ge, gender, duration, severity and complications of hypertension. A mean du ration of diabetes mellitus in group I was 6.8 years. Conventional and automatic blood pressure and heart rate measurements, cont inuous ECG recordings, echocardiograms and laboratory tests were obtained i n all patients. SMI was more frequent in group I than in group II (29.3% vs 12.5%, P < 0.05 ). In group I the total duration of SMI was longer (37.3 vs 2.8 min, P < 0. 001) and the total number of silent episodes was larger (15.5 vs 2.6, P < 0 .001). No inter-group differences were seen in conventional and automatic b lood pressure and heart rate measurements. Both groups did not differ signi ficantly in left ventricular mass index (LVMI) or the proportion of patient s with left ventricular hypertrophy (LVH) (75.6% vs 60%). Lipid profile in both groups indicated an increased risk of CAD, but without significant dif ferences. In conclusion, in patients with essential arterial hypertension and diabete s mellitus, the incidence and severity of SMI were clearly higher than in h ypertensives with normal carbohydrate metabolism. Employment of modern diag nostic techniques in hypertensives permits identification of those at great er risk, which may have further clinical implications.