Conventional tobacco and electronic cigarettes differentially affect cardiovascular health in male and female mice

Although promoted as a safer alternative, the cardiovascular effects of electronic cigarettes (E-cigs) compared with tobacco cigarettes (T-cigs) are largely unknown. Thus, we evaluated aerosol exposures and the potential additive effects of a Western diet (WD) on cardiovascular health in multiple cohorts of hyperlipidemic (<i>Apoe^-/-</i>) male and female mice. The mice were fed either a normal diet (ND) or WD and exposed daily during their dark cycle to either air (control), E-cig, or T-cig aerosol for 12 wk. Results showed that plasma nicotine levels in the E-cig and T-cig exposed mice were similar to those of human users. In both sexes, body weight was increased by WD, whereas caloric intake was increased by T-cig on both diets in both sexes and by E-cig on ND only in male mice. T-cig-exposed males and females on WD had significantly greater atherosclerotic lesions than their ND counterparts, whereas the E-cig effect was only in males. In addition, on WD, T-cig-exposed females had greater lesions than T-cig-exposed males and E-cig-exposed females. Left ventricular (LV) functional indices were significantly decreased to a similar extent by E-cigs and T-cigs on both diets in both sexes. Structurally, T-cigs increased LV mass on both diets and sexes, whereas E-cigs increased LV mass only on WD in both sexes. Overall, the findings demonstrated that both electronic and tobacco cigarettes impose differential adverse effects on caloric consumption, atherosclerosis, and cardiovascular health in diet- and sex-dependent manners, suggesting that E-cig is not a safer alternative to T-cig.<b>NEW & NOTEWORTHY</b> Effects of electronic cigarettes (E-cigs) compared with tobacco cigarettes (T-cigs) in the Western population are largely undetermined. Here, we assessed chronic, intermittent exposures to either E-cigs or T-cigs on cardiovascular parameters in hyperlipidemic mice with similar nicotine levels. Our findings suggest that both E-cigs and T-cigs imposed adverse effects on cardiac function, heart chamber size, and atherosclerotic lesions in diet and sex-dependent manners, suggesting that electronic cigarettes are not a safer alternative to conventional cigarettes.