Hypoglycemia may exert proarrhythmogenic effects on the heart and insulin induced hypoglycemia has been considered responsible for nocturnal death in diabetic patients. Even so hypoglycemia associated fatal cardiac arrhythmia is difficult to document.

Objective: examined the effect of hypoglycemia on episodes of arrhythmias and cardiac repolarization disorders in diabetic mellitus (DM) patients.

Design and Methods: prospective study in which we included 30 subjects with DM who underwent of simultaneous ambulatory 24 hours electrocardiographic holter and continuous interstitial glucose monitoring (FREE STYLE system). Inclusion criteria: men and women > or = 50 years old with a type 2 insulin-treated DM and 2 or more major cardiovascular risk factors (hypertension, dyslipidemia, active smoking, overweight or obesity) or subjects older than 18 years old with a history of type 1 DM of more than 10 years who sign an informed consent. Exclusion criteria: pacemakers, treatment with drugs that prolong QT, chronic atrial fibrillation or branch blocks, previous stroke, heart failure stage III-IV, Wolf Parkinson White Syndrome.

Results: A total of 30 patients with DM participated in this study; 14 patients with type 1 DM (46.67%) and 16 patients with type 2 DM (53.33%). Within the group of type 1 DM, 61.54% presented hypoglycemic events vs. 56.25% of the patients in type 2 DM group, (p= 0.774) which correlates with the increased risk of hypoglycemic events in type 1 DM group. A total of 60% of the patients presented hypoglycemic events (n= 18) independently of glucose levels, and 40% of the patients (n=12) did not present it. Most of the hypoglycemic events (72.22% p=0.035) did not correlate with an arrhythmia event or cardiac repolarization disorder.

Conclusions: In our group of patients, high cardiovascular risks and long-term duration of type 1 or type 2 DM were strong enough factors to develop arrhythmia, independently of glucose levels. Maybe it would be necessary to study patients with a 48-hour holter in order to find out this association.


C. Musso: None. N.S. Sforza: None. Y.J. Morosan Allo: None. R.G. Clemente: None. A. Pavesi: None. C.C. Folino: Other Relationship; Self; Boehringer Ingelheim Pharmaceuticals, Inc.

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