QT dispersion in microalbuminuric Type 1 diabetic patients without myocardial ischemia

Microalbuminuria is associated with an increased risk of cardiac death. We assessed whether urinary albumin excretion is related to abnormalities of t he QT interval independently of myocardial ischemia. Thirty-four patients w ith type 1 diabetes who were free from ischemic heart disease on the basis of normal stress electrocardiography and echocardiography were studied. Max imal QT interval and dispersion were significantly greater in the group wit h microalbuminuria (n = 17) compared to controls (n = 17) with normal urina ry albumin excretion (394 [26.1] vs. 373.8 [27.8] ms; P=.034 and 62.4 [21.8 ] vs. 42.7[11.6] arbitrary units; P=.009). Autonomic function was similar b etween the groups. Urinary albumin excretion correlated positively with QT dispersion (P = .023). These data suggest that in type 1 diabetic patients, QT abnormalities can occur independently of autonomic dysfunction or myoca rdial ischemia and may be related to the processes which increase urinary a lbumin leakage. (C) 2000 Elsevier Science Inc. All rights reserved.