Research Paper
Tobacco and Electronic Cigarettes Adversely Impact ECG Indices of Ventricular Repolarization
Tobacco and Electronic Cigarettes Adversely Impact ECG Indices of Ventricular Repolarization: Implication for Sudden Death Risk
https://journals.physiology.org/doi/abs/10.1152/ajpheart.00738.2019
Abstract
Tobacco cigarette(TC) smoking is associated with increased sudden death risk, perhaps through adverse effects on ventricular repolarization(VP). The effect of electronic-cigarettes(ECs) on VP is unknown. Objective To test the hypothesis that TCs and ECs have similar adverse effects on electrocardiogram(ECG) indices of VP, and these effects are attributable to nicotine. Methods ECG recordings were obtained in 37 TC-smokers, 43 EC-users, and 65 non-users. Primary outcomes, Tpeak-to-Tend(Tp-e), Tp-e/QT, and Tp-e/QTc, were measured in TC-smokers pre/post straw-control and smoking one TC, and in EC-users and non-users pre/post straw control and using an EC with and without nicotine(different days). Results Mean values of the primary outcomes were not different among the 3 groups at baseline. In TC-smokers, all primary outcomes including the Tp-e(12.9±5.0%vs1.5±5%, p=0.017), Tp-e/QT (14.9±5.0%vs0.7±5.1%, p=0.004), and Tp-e/QTc(11.9±5.0%vs2.1±5.1%, p=0.036), were significantly increased pre/post smoking one TC compared to pre/post straw-control. In EC-users, the Tp-e/QT(6.3±1.9%, p=0.046) was increased only pre/post using an EC-with-nicotine, but not pre/post the other exposures. The changes relative to the changes after straw-control were greater after smoking the TC compared to using the EC with nicotine for Tp-e(11.4±4.4%vs1.1±2.5%, p<0.05) and Tp-e/QTc(9.8±4.4%vs-1.6±2.6%, p=0.05), but not Tp-e/QT(14.2 ± 4.5%vs4.2±2.6%, p=0.06) . Heart rate increased similarly after the TC and EC-with-nicotine. Conclusions Baseline ECG-indices of VP were not different among TC-smokers, EC-users and non-users. An adverse effect of acute TC smoking on ECG indices of VP was confirmed. In EC-users, an adverse effect of using an EC-with-nicotine, but not without nicotine, on ECG indices of VP was also observed.
Secondhand Smoke Exposure and Subsequent Academic Performance Among U.S. Youth
Introduction
Previous research shows the associations between secondhand smoke exposure and health consequences among youth, but less is known about its effect on academic performance. This study examines a dose–response relationship between secondhand smoke exposure and subsequent academic performance among U.S. youth.
https://www.ajpmonline.org/article/S0749-3797(20)30048-9/fulltext
Methods
Data were from a nationally representative sample of youth non–tobacco users (aged 12–16 years) in Wave 2 (2014–2015) who completed Wave 3 (2015–2016) of the Population Assessment of Tobacco and Health Study ( n=9,020). Past-7-day number of hours exposed to secondhand smoke at Wave 2 and academic performance at Wave 3 (1=Mostly As to 9=Mostly Fs) were assessed. Weighted multivariable linear regression models were used to examine the association between hours of self-reported secondhand smoke exposure at Wave 2 and academic performance at Wave 3 (1=Mostly Fs, 9=Mostly As), adjusting for covariates including sociodemographics, prior academic performance, internalizing and externalizing problems, and substance use problems. Analyses were conducted in 2019.
Results
More than 30% of U.S. youth non–tobacco users were exposed to secondhand smoke in the past 7 days. Compared with unexposed youth at Wave 2, those who were exposed for 1–9 hours had poorer academic performance at Wave 3 (adjusted regression coefficient= −0.11, 95% CI= −0.18, −0.04), and those who were exposed for ≥10 hours at Wave 2 had even poorer academic performance (adjusted regression coefficient = −0.31, 95% CI= −0.45, −0.18).
Conclusions
A dose–response relationship was observed between secondhand smoke exposure and academic performance among U.S. youth. Reducing youth secondhand smoke exposure may promote academic performance and subsequent educational attainment.