Incidence of prolonged QTc and severe hypoglycemia in type 1 diabetes: the EURODIAB Prospective Complications Study.
AIMS
To assess the independent role of severe hypoglycemia on 7-year cumulative incidence of prolonged QTc in a large cohort of patients with type 1 diabetes.


METHODS
People with type 1 diabetes recruited by the EURODIAB Prospective Complications Study who had normal QTc were examined at baseline and after 7 years with standardized methods (n = 1415; mean age ± SD 32.1 ± 9.6 years; diabetes duration 14.2 ± 8.8 years). Hypoglycemic episodes were assessed by a questionnaire. QTc was calculated according to Bazett's formula. In logistic regression analysis, we examined the role of severe hypoglycemia (none, 1-2, or 3 and more episodes/year) on the cumulative incidence of prolonged QTc, independently of age, sex, HbA1c, blood pressure, BMI, physical activity, distal symmetrical and autonomic neuropathy.


RESULTS
In total, 264/1415 (17%) patients had incident prolonged QTc. Compared to those with persistently normal QTc, a greater proportion of incident cases had 3 and more hypoglycemic episodes at baseline (16.3 vs 11.2%, p = 0.03) and after 7 years (15.2 vs 9.6%, p = 0.01). In logistic regression analysis, 3 or more episodes of severe hypoglycemia at baseline did not increase cumulative incidence of prolonged QTc (OR 1.34, 95% CI 0.88-2.03). By contrast, severe hypoglycemia at the follow-up examination was associated with higher incidence of QTc prolongation (OR 1.68, 1.09-2.58), which reverted to not significant after adjustment for diabetic neuropathy.


CONCLUSIONS
Severe hypoglycemia was not associated with incidence QTc prolongation in type 1 diabetic patients from the EURODIAB PCS.
['Amione|Cristina|C|', 'Giunti|Sara|S|', 'Fornengo|Paolo|P|', 'Soedamah-Muthu|Sabita S|SS|', 'Chaturvedi|Nish|N|', 'Fuller|J H|JH|', 'Barutta|Federica|F|', 'Gruden|Gabriella|G|', 'Bruno|Graziella|G|']
D000328:Adult D001794:Blood Pressure D015331:Cohort Studies D003922:Diabetes Mellitus, Type 1 D003925:Diabetic Angiopathies D003929:Diabetic Neuropathies D005260:Female D005500:Follow-Up Studies D006801:Humans D007003:Hypoglycemia D015994:Incidence D008133:Long QT Syndrome D008297:Male D012720:Severity of Illness Index D055815:Young Adult
QTc Hypoglycemia Complications Surveys