QT interval prolongation and mortality in type 1 diabetic patients: a 5-year cohort prospective study. Neuropathy Study Group of the Italian Society of the Study of Diabetes, Piemonte Affiliate.
OBJECTIVE
The aim of the study was to assess the relationship between QT interval prolongation and mortality in type 1 diabetic patients.


METHODS
Data on survival after 5 years were obtained from 316 of 379 patients (83.3%) who took part in a study on the prevalence of diabetic neuropathy and QT interval prolongation.


RESULTS
Mortality at 5 years was 6.32%. Patients who survived were significantly younger (P = 0.04), had a shorter duration of diabetes (P = 0.01), had lower systolic (P = 0.004) and diastolic (P = 0.03) blood pressure levels, and had a shorter QT interval corrected for the previous cardiac cycle length (QTc) (P = 0.000005) than subjects who died. In univariate analysis, patients had a higher risk of dying if they had a prolonged QTc (odds ratio [OR] 20.14 [95% CI 5.7-70.81) or if they were affected by autonomic neuropathy (3.55 [1.4-8.9]). QTc prolongation was the only variable that showed a significant mortality OR in multivariate analysis (24.6 [6.51-92.85]; P = 0.0000004).


CONCLUSIONS
This is the first cohort-based prospective study indicating that QTc prolongation is predictive of increased mortality in type 1 diabetic patients.
Veglio
M
M
Ospedale Mauriziano Umberto I di Torino, University of Torino, Italy. veglio@onw.net
Sivieri
R
R
Chinaglia
A
A
Scaglione
L
L
Cavallo-Perin
P
P
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D001145:Arrhythmias, Cardiac / Q000453:epidemiology*; D001794:Blood Pressure; D015331:Cohort Studies; D003922:Diabetes Mellitus, Type 1 / Q000401:mortality* / Q000503:physiopathology*; D003929:Diabetic Neuropathies / Q000453:epidemiology; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012016:Reference Values