Effects of Electronic vs. Tobacco Cigarettes on Cardiovascular Health in Male and Female Mice

Abstract

Objective: Smoking electronic cigarettes (E-cig) has been promoted as a safer alternative to conventional tobacco cigarettes (CIG) and thus become popular, especially among younger generations. However, one mode of smoking nicotine containing products vs. another on the effects on health and gender are largely unknown. Hypothesis: Both E-cig and CIG have adverse effects on body weight as well as cardiovascular health. Methods: To closely mimic the Western population, we investigated the effects of two insults (diet and/or nicotine exposure) in mice. Nine-week old male and female Apoe−/− mice (C57BL/6 background) were placed on normal chow or high-fat diet (Western diet, WD) and/or exposed to air, E-cig, or CIG for 12 weeks. The E-cig and Cig exposures used a chronic-intermittent puff protocol for 10 hours a day, seven days a week during their active (dark) circadian cycle. Changes in body weight, cardiac structure, function, and atherosclerotic lesions were assessed and compared. Results: In males, body weight was significantly reduced by CIG exposure with both the normal diet or WD, while in females, only on WD. This suggests that CIG exposure had gender-dependent effects on the body weight. E-cig exposure, however, did not affect the body weight in both males and females on either diet compared with the controls. Echocardiographic analysis showed that left ventricular mass was increased while ejection fraction was reduced by both e-cigarette and CIG-exposure. These data suggest that both modes of nicotine delivery had gender-independent adverse effects on cardiac structure and function. En face analysis of the aorta in both genders showed that two insults (CIG and WD) are necessary to induce significantly greater lesions. There were no significant increases in lesions with E-Cigs. This suggests that CIG exposure had insult-dependent but gender-independent effects on atherosclerotic lesion development. Summary: These findings suggest that both electronic cigarettes and conventional tobacco cigarettes impose adverse effects on the body weight and cardiovascular health in modes of nicotine- and gender-dependent manners. Funding: Department of Defense CDMRP Grant PR 190942 (TCF) and DODCDMRP Grant PR190942-P1 (KPR). This is the full abstract presented at the American Physiology Summit 2024 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.