Prevalence of increased QT interval duration and dispersion in type 2 diabetic patients and its relationship with coronary heart disease: a population-based cohort.
OBJECTIVE
To evaluate the prevalence of prolonged QT interval and dispersion in a population-based cohort of type 2 diabetic patients and their relationship with clinical and metabolic variables.


METHODS
Cross-sectional population-based cohort.


METHODS
Diabetes clinics and general practitioners in Casale Monferrato (Northern Italy).


METHODS
A total of 1357 patients with known type 2 diabetes (70% of the cohort).


METHODS
Albumin excretion rate and coronary heart disease (CHD); a standard supine 12-lead electrocardiogram (ECG) was recorded and coded according to the Minnesota code criteria. QT interval corrected for heart rate (QTc) > 0.44 s and QTc dispersion > 0.080 s were considered abnormally prolonged.


RESULTS
Prevalence of increased QTc duration and QTc dispersion were 25.8% (95% CI 23.5-28.3) and 33.1% (95% CI 30.6-35.7), with no sex differences. No metabolic differences were found, apart from fibrinogen and creatinine levels, which were higher in patients with increased QTc dispersion. Patients with CHD had higher mean adjusted values of QTc and QTc dispersion, whereas no association was found with albumin excretion rate (AER) and diabetes treatment. QTc duration and QTc dispersion were significantly correlated (0.17, P < 0.001). In multiple regression analysis, only CHD was independently associated with QTc, after adjustment for age and sex (beta=0.010, P < 0.001, R2=2.5%); as regards QTc dispersion, a similar association with CHD was found (beta=0.20, P < 0.001, R2=4.8%).


CONCLUSIONS
This population-based study shows a considerably high prevalence of increased QTc and QTc dispersion in type 2 diabetic patients and their association with CHD. These findings have both epidemiological and clinical relevance, as they might be implicated in the excess mortality risk of type 2 diabetic patients.
Veglio
M
M
Evangelico Valdese Hospital, Torino, Italy. veglio@onw.net
Bruno
G
G
Borra
M
M
Macchia
G
G
Bargero
G
G
D'Errico
N
N
Pagano
G F
GF
Cavallo-Perin
P
P
D000368:Aged; D001794:Blood Pressure; D015992:Body Mass Index; D015331:Cohort Studies; D003327:Coronary Disease / Q000150:complications; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000188:drug therapy / Q000378:metabolism; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D007558:Italy / Q000453:epidemiology; D008133:Long QT Syndrome / Q000150:complications* / Q000453:epidemiology; D008297:Male; D011159:Population Surveillance; D015995:Prevalence
D007004:Hypoglycemic Agents