Effect of uncomplicated obesity on QT interval in young men

Abstract

INTROduCTION QT prolongation and obesity are associated with ventricular arrhythmia and sudden cardiac death. The relationship between uncomplicated obesity and QT inter val prolongation is not clear.ObjECTIvEs The aim of the study was to investigate the effects of uncomplicated obesity on QT inter val in young men.PATIENTs ANd mEThOds A total of 122 men, including 59 obese patients and 63 controls, were recruited into the study. Patients with hypertension, diabetes mellitus, and ischemic heart disease were ineligible. Body mass index (BMI) of all patients was calculated. QT inter val was measured from the precordial lead - V 5 , and corrected QT (QT C ) was calculated using the Bazett's formula. REsuLTsMean age, BMI, and waist circumference (WC) of obese patients and controls were as follows: 22.0 ±3.0 years, 36.2 ±2.2 kg/m², and 114 ±8.1 cm; 22.6 ±2.9 years, 24.7 ±2.5 kg/m², and 81.6 ±7.5 cm, respectively. There was a statistically significant difference between the obese and control groups with regard to BMI and WC (P <0.001). Furthermore, statistically significant differences were observed between the 2 groups in terms of QT C (407.9 ±17.1 ms vs. 397.7 ±14.0 ms, respectively, P <0.001), systolic (126.9 ±8.2 mmHg vs. 114.2 ±11.1 mmHg, respectively, P <0.001) and diastolic blood pressure (78.3 ±4.5 mmHg vs. 66.9 ±10 mmHg, respectively, P <0.001). There was a positive correlation between QT C inter val and both WC (r = 0.357, P <0.001) and BMI (r = 0.424, P <0.001). There was no association between QT C and blood pressure.CONCLusIONs Uncomplicated obesity in young men is associated with QT inter val prolongation. Weight gain may inversely affect cardiac repolarization in uncomplicated obesity. KEy wORdscorrected QT, prolonged QT inter val, uncomplicated obesity parative ultra-centrifuge. Clin Chem. 1972; 18: 449-502. 13 Matthews DR, Hosker JP, Rudenski AS, et al. Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man. Diabeto logia. 1985; 28: 412-419. 14 Bazzet HC. An analysis of the time-relations of electrocardiograms. Heart. 1920; 7: 353-370. 15 Kohno I, Takusagawa M, Yin D, et al. QT dispersion in dipper- and nondipper-type hypertension. Am J Hypertens. 1998; 11: 280-285. 16 Perkiömäki JS, Huikuri HV, Koistinen JM, et al. Heart rate variability and dispersion of QT inter val in patients with vulnerability to ventricular tachycardia and ventricular fibrillation after previous myocardial infarction. J Am Coll Cardiol. 1997; 30: 1331-1338. 17 Schwartz PJ, Moss AJ, Vincent GM, Crampton RS. Diagnostic criteria for the long QT syndrome. An update. Circulation. 1993; 88: 782-784. 18 Sagie A, Larson MG, Goldberg RJ, et al. An improved method for adjusting the QT inter val for heart rate (the Framingham Heart Study). Am J Cardiol. 1992; 70: 797-801. 19 Witchel HJ, Hancox JC. Familial and acquired long qt syndrome and the cardiac rapid delayed rectifier potassium current. Clin Exp Pharmacol Physiol. 2000; 27: 753-766. 20 Vincent GM, Timothy...

Effect of obesity and weight loss on ventricular repolarization: a systematic review and meta‐analysis

“…The clinical significance of QTc and QT or QTc dispersion prolongation associated with obesity is uncertain. QTc and QT or QTc dispersion values, when prolonged in the studies included in this meta‐analysis, were generally modestly so . QTc values > 500 msec and QT or QTc dispersion values > 80 msec were rare .…”

“…Most of the studies in this meta‐analysis consisted predominantly or entirely of women . In the only study consisting entirely of men, mean QTc was significantly longer in 59 obese subjects than in 63 non‐obese controls . Park et al .…”

“…Multiple studies assessing the relation between obesity and ventricular repolarization have reported prolongation of QTc and QT or QTc dispersion with increasing body mass index. Some studies have reported a decrease in these variables with purposeful weight loss . We present herein the results of a meta‐analysis of controlled studies assessing QTc and/or QT or QTc dispersion in normal weight persons and obese ± overweight subjects and of studies investigating the effects of weight loss on these variables in obese ± overweight subjects.…”

Relation of Left Ventricular Mass to QTc in Normotensive Severely Obese Patients

“…Although the mechanism of sudden cardiac death in this population is unknown, ventricular tachyarrhythmias are suspected to play a role (27,28). For this reason ventricular repolarization has been the subject of investigative interest in severely obese subjects as well as in those with less severe obesity (6,7,8,9,10,11,12,13,29,30,31,32).…”

“…Known causes of QTc prolongation include the congenital long QT syndromes, the Brugada syndrome, electrolyte disturbances (hypokalemia, hypomagnesemia, hypocalcemia), selected drugs (e.g., certain anti‐arrhythmic drugs, phenothiazines, tricyclic antidepressants, erythromycin in combination with certain antihistamines, pentamidine, and certain anti‐malarials), liquid protein and starvation diets, hypothyroidism, central nervous system lesions, severe bradycardia, mitral valve prolapse, acute myocardial infarction, and possibly obstructive sleep apnea (3,4,5). Multiple studies of obese subjects have reported prolongation of QTc and/or increased QT or QTc dispersion, suggesting an association between obesity and delayed ventricular repolarization (5,6,7,8,9,10,11,12,13). Patient populations in these studies were heterogeneous.…”