High risk of abnormal QT prolongation in the early morning in diabetic and non-diabetic patients with severe hypoglycemia.
BACKGROUND
Several studies have suggested that the occurrence of severe hypoglycemia during sleep may be more dangerous for cardiac arrhythmia than that in the day-time.


METHODS
We performed a retrospective study between January 2006 and March 2012 to assess electrocardiograms during severe hypoglycemia in patients with or without diabetes.


RESULTS
A total of 59,602 patients who visited the emergency room by ambulance were screened, and 287 patients with severe hypoglycemia were enrolled. The median blood glucose levels in patients with (DM, n = 192) and without diabetes (non-DM, n = 95) were 30 and 45 mg/dL, respectively. During severe hypoglycemia, the incidence of abnormal QT prolongation was significantly higher in the early morning (4-10 a.m.) than at other times (DM group, 74.3% versus 54.1%, P = 0.02; non-DM group, 78.3% versus 50.0%, P = 0.01). Multivariate logistic regression analysis identified the occurrence of severe hypoglycemia in the early morning as a strong factor for abnormal QT prolongation (DM group, odds ratio [OR] 2.80, 95% confidence interval [CI] 1.15-6.80, P = 0.02; non-DM group, OR 4.53, 95% CI 1.30-15.74, P = 0.01).


CONCLUSIONS
The incidence of abnormal QT prolongation during severe hypoglycemia was significantly higher in the early morning than at all other times, independent of the cause of severe hypoglycemia.
['Tsujimoto|Tetsuro|T|', 'Yamamoto-Honda|Ritsuko|R|', 'Kajio|Hiroshi|H|', 'Kishimoto|Miyako|M|', 'Noto|Hiroshi|H|', 'Hachiya|Remi|R|', 'Kimura|Akio|A|', 'Kakei|Masafumi|M|', 'Noda|Mitsuhiko|M|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D001145:Arrhythmias, Cardiac D053840:Brugada Syndrome D000075224:Cardiac Conduction System Disease D057906:Circadian Clocks D016757:Death, Sudden, Cardiac D003924:Diabetes Mellitus, Type 2 D004562:Electrocardiography D005260:Female D006329:Heart Conduction System D006801:Humans D007003:Hypoglycemia D008133:Long QT Syndrome D008297:Male D008875:Middle Aged D012189:Retrospective Studies D012306:Risk
QT prolongation diabetes severe hypoglycemia Arrhythmia nocturnal hypoglycemia