Chronic Electronic Cigarette Users Exhibit Reduced Cardiorespiratory Fitness and Associated Increased Cardiovascular Disease Risk

Abstract

BACKGROUND: Electronic cigarettes (e-cigs) are popular tobacco products that are currently advertised as a safer alternative to traditional cigarettes. Preliminary data, primarily from animal studies, suggests that e-cigs are associated with an increased cardiovascular disease (CVD) risk. Cardiorespiratory fitness is a marker of cardiovascular (CV) health and a predictor of CV mortality, which is diminished in traditional tobacco users. However, the effect of chronic e-cigs usage on cardiorespiratory fitness and associated CVD risk in otherwise healthy individuals without established CVD or CVD risk factor, is currently unknown. PURPOSE: The purpose of this study was to investigate the impact of chronic e-cig use on cardiorespiratory fitness and CVD risk in healthy young adults. METHODS: Ten chronic e-cig users (ECU, 4 males and 6 females; age: 24±3 yr; e-cigs usage 3±1.5 yr.) and ten demographical matched, never users (NU, 4 males and 6 females; age: 22.7±2 yr.) participated in this study. Cardiorespiratory fitness was measured by peak oxygen consumption (VO2peak) via a respiratory gas exchange analyzer during a cardiopulmonary exercise test. CVD risk was calculated using Framingham’s 30-year CVD risk score accounting for 8 risk factors (age, sex, systolic blood pressure, total cholesterol, high-density lipoprotein, presence of diabetes mellitus, hypertension treatment, and smoking status). RESULTS: Chronic e-cig users exhibited significantly lower VO2peak (ECU vs. NU; 30.9±4.9 vs. 37.8±6.4 ml/kg/min; p=0.015) and percent predicted (ECU vs. NU; 85.9±16 vs. 105.4±14 % predicted; p=0.001) when compared to never users. Framingham’s 30-year CVD risk score was significantly higher in ECU than in NU (7.7± 4.8, vs. 2.7±0.8 %; p=0.017). Furthermore, an inverse association was identified between VO2peak and 30-year CVD risk ( r=-0.720; p= 0.030). CONCLUSIONS: For the first time, we have identified significantly reduced cardiorespiratory fitness, a marker of CV health and mortality risk, in chronic e-cig users when compared to never users. In addition, chronic e-cig users exhibit higher CVD risk scores. Results from our study imply a negative effect of chronic e-cig use on CV health in otherwise young, apparently healthy adults. Future studies are warranted to investigate the long-term effects of e-cig use on CV health. Supported in part by a Rapid Response Project NIDA/FDA (PRM). Supported in part by a Rapid Response Project NIDA/FDA (PRM). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.