Elevation of QT dispersion after obesity drug sibutramine.
BACKGROUND
QT dispersion (QTd) is an arrhythmia parameter that can be used to assess homogeneity of cardiac repolarization. An antiobesity drug sibutramine is linked with several cardiovascular adverse events, including arrhythmias. Previous studies showed that sibutramine may prolong the QT interval and may be associated with cardiac arrest.


OBJECTIVE
The aim of this study was to evaluate the effect of sibutramine on QTd.


METHODS
The study group consisted of 65 consecutive patients with obesity. All patients were to receive 15 mg of sibutramine once a day in addition to standard care for lifestyle change. Twelve-lead ECG was performed before the onset of the medication and after 16 weeks of treatment. QTd was calculated.


RESULTS
Three individuals were withdrawn from the study because of the adverse effects of sibutramine. Sixty-two patients with obesity were recruited into the study. All patients were women (62, 100%). Body weight (106.3 ± 15.0 kg vs. 101.6 ± 16.9 kg, P < 0.001) and low-density lipoprotein cholesterol (128.4 ± 29.7 mg/dl vs. 111.6 ± 24.6 mg/dl, P < 0.001) levels were significantly decreased whereas QTd (46.1 ± 22.6 ms vs. 53.7 ± 16.7 ms, P = 0.026) was significantly increased after 16 weeks of sibutramine treatment. The increase in QTd was not correlated with the decrease in body weight. There was no correlation between QTd and any conditions such as diabetes or hypertension.


CONCLUSIONS
This study has shown an elevation in QTd, which may lead to cardiac arrhythmias, after sibutramine treatment. Molecular mechanisms may play role in increasing QTd. Further randomized studies are needed to clarify cardiac adverse events of the sibutramine.
Yalcin
Ahmet A
AA
Department of Cardiology, Kecioren Teaching and Research Hospital, Kecioren, Ankara, Turkey.
Yavuz
Bunyamin
B
Ertugrul
Derun T
DT
Algul
Beyza
B
Yilmaz
Hamiyet
H
Deveci
Onur S
OS
Kucukazman
Metin
M
Ata
Naim
N
Demirel
Gokhan
G
Dal
Kursat
K
Tutal
Emre
E
D000328:Adult; D019440:Anti-Obesity Agents / Q000009:adverse effects*; D001145:Arrhythmias, Cardiac / Q000139:chemically induced* / Q000503:physiopathology; D031204:Caloric Restriction; D003131:Combined Modality Therapy; D003503:Cyclobutanes / Q000009:adverse effects*; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000187:drug effects* / Q000503:physiopathology; D006801:Humans; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy / Q000188:drug therapy* / Q000503:physiopathology; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014421:Turkey
D019440:Anti-Obesity Agents; D003503:Cyclobutanes; C058254:sibutramine