Author + information
- Burak Hünük1,
- Özgür Çağaç2,
- Okan Erdoğan2,
- Alper Kepez2,
- Bülent Mutlu2,
- Muzaffer Değertekin3 and
- Çetin Erol4
It is well known that the prolongation of QT interval is associated with cardiovascular mortality and morbidity. The effects of age and gender on QT/rate corrected QT interval (QTc) have previously been investigated. However, metabolic factors on QT interval is not well established. Our aim was to investigate the effects of body mass index (BMI), metabolic syndrome (MS), diabetes mellitus (DM), glomerular filtration rate (GFR), hypertension (HT) and mean arterial pressure (MAP) on QTc.
ECGs were obtained from the HAPPY (Heart Failure Prevalence and Predictors in Turkey) study which included randomly selected 4650 subjects ≥35 years with laboratory and clinical data from Turkey. After the exclusion of subjects with missing ECG or data, ECG abnormalities effecting QTc, anti arrhythmic use or established coronary artery disease; 2984 subjects ([mean±SD]age, 50±11, [range]35-80 years) were enrolled in the study (female n [overall%]:1723 [58,6%]). MS was defined according to the revised third National Cholesterol Education Program Adult Treatment Panel. GFRs were calculated by Cockroft-Gault formula and grouped into high (≥60 ml/min) and low (<60 ml/min).
QTc was significantly longer in MS (meanQTc±SEM; 406,6±0,5 vs 404,9±0,4 p=0,005), HT (406,5±0,5 vs 405,0±0,4, p=0,014), low GFR (409±1,2 vs 405,6±0,3, p=0,007) and high BMI group (407,1±0,6 vs 405±0,4, p=0,002). There was a significant negative correlation with GFR and QTc (r:-0,047, p=0,007). Multivariate regression model for QTc is shown in table-1.
After adjusting for MAP and GFR; age and BMI revealed as independent predictors of QTc in adult Turkish population. This finding might be attributed to a probable sub-clinical cardiac hypertrophy or chamber enlargement in high BMI.
|r||p||β||p||Confidence Interval (95%)|
|Age (years)||0,096||< 0,001||0,073||0,001||( 0,050-0,178)|
|BMI (kg/m2)||0,066||< 0,001||0,067||0,001||( 0,1-0,4)|
|GFR (ml/min)||-0,047||0,007||0,008||0,697||( -0,035-0,053)|
|MAP (mmHg)||0,079||0,001||0,041||0,058||( -0,002-0,106)|
Multiple regression analysis of variables predictive of QTc