Diabetologia
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Randomized Controlled Trial Comparative Study Clinical Trial
Effects of metoprolol on QT interval and QT dispersion in Type 1 diabetic patients with abnormal albuminuria.
The excess mortality in diabetes is mainly due to cardiovascular causes and almost confined to patients with abnormal albuminuria. Compared to healthy subjects, diabetic patients have a prolonged QT interval and increased QT dispersion. In non-diabetic subjects, as well as in Type 1 diabetic patients with overt nephropathy, a prolonged QT interval and increased QT dispersion are associated with cardiac morbidity and mortality. There is an increasing number of studies on effects of beta blocker treatment on QT interval and QT dispersion in non-diabetic subjects. In contrast, there are no studies on the effects of beta blocker treatment on QT interval and QT dispersion in patients with diabetes. The aim of our study was to describe the effects of metoprolol treatment on QT interval and QT dispersion in a group of well-characterised Type 1 diabetic patients with elevated urine albumin excretion. ⋯ This study is the first to address the QTc interval and QTc dispersion in Type 1 diabetic patients treated with metoprolol. Beta blocker treatment caused a decrease in QTc interval but no change in QTc dispersion. These results may in part explain the pronounced cardioprotective effect of beta blocker treatment in diabetic patients with cardiovascular disease.