Sex difference in QTc prolongation in chronic institutionalized patients with schizophrenia on long-term treatment with typical and atypical antipsychotics
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The rate-corrected electrocardiographic QT (QTc) interval may significantly increase in patients with schizophrenia taking antipsychotics. The objective of this naturalistic study was to assess the prevalence of prolonged QTc interval in a large population of inpatients with chronic schizophrenia and to explore QTc relationship with demographic variables and prescribed treatments.
Materials and methods
Electrocardiograms were obtained from age- and sex-matched 456 controls and 1,006 inpatients with schizophrenia (male/female = 689/317) taking antipsychotics. QTc prolongation was defined as a mean value of two standard deviations above the controls. The adjusted relative risk was calculated using logistic regression analysis.
QTc prolongation was present in 45 (4.5%) of 1,006 patients overall. Fewer men (3.2%, 22 of 689) than women (7.3%, 23 of 317) displayed QTc prolongation (p < 0.004). Moreover, QTc intervals were shorter in male (391 ± 31 ms) than female subjects (400 ± 37 ms) (p < 0.001). Clozapine was found to produce a longer QTc intervals compared to risperidone and typical antipsychotics. Furthermore, multiple regression analysis showed that significant predictors for QTc prolongation were comorbid cardiovascular disease, antipsychotic types, sex, and age (all p < 0.01).
Our present findings suggest that there are sex differences in the prevalence of QTc prolongation and QTc lengthening in schizophrenia. Antipsychotic types are risk factors for QTc prolongation, and risks are substantially higher for clozapine.
KeywordsSchizophrenia Antipsychotics QT prolongation Electrocardiography
This study was funded by the Stanley Medical Research Institute (03T-459 and 05T-726) and the United States National Institute of Health (K05-DA0454, P50-DA18827, and U01-MH79639).
- Bazett HC (1920) An analysis of the time-relations of electrocardiograms. Heart 7:353–370Google Scholar
- Khan SP, Dahlvani S, Vieweg WVR (1998) Electrocardiographic QT interval in a geropsychiatric inpatient population: a preliminary study. Med Psychiatr 1:71–74Google Scholar
- Ramos-Ríos R, Arrojo-Romero M, Paz-Silva E, Carballal-Calvo F, Bouzón-Barreiro JL, Seoane-Prado J, Codesido-Barcala R, Crespí-Armenteros A, Fernández-Pérez R, López-Moríñigo JD, Tortajada-Bonaselt I, Diaz FJ, de Leon J (2010) QTc interval in a sample of long-term schizophrenia inpatients. Schizophr Res 116(1):35–43PubMedCrossRefGoogle Scholar
- Stramba-Badiale M, Spagnolo D, Bosi G, Schwartz PJ (1992) Are gender differences in QTc present at birth? MISNES investigators. Multicenter Italian study on neonatal electrocardiography and sudden infant death syndrome. Am J Cardiol 75(17):1277–1278Google Scholar
- van Noord C, Dörr M, Sturkenboom MC, Straus SM, Reffelmann T, Felix SB, Hofman A, Kors JA, Haring R, de Jong FH, Nauck M, Uitterlinden AG, Wallaschofski H, Witteman JC, Völzke H, Stricker BH (2010) The association of serum testosterone levels and ventricular repolarization. Eur J Epidemiol 25(1):21–28PubMedCrossRefGoogle Scholar