Electronic cigarettes cause alteration in cardiac structure and function in diet-induced obese mice

PLoS One. 2020 Oct 1;15(10):e0239671. doi: 10.1371/journal.pone.0239671. eCollection 2020.


In spite of the widespread use of electronic cigarettes, also known as e-cigarettes, and the proposed adverse cardiac effects of nicotine, the detrimental effects of e-cigarettes on the heart are not well known. This study examines the detrimental effects of e-cigarettes with nicotine at doses that yield circulating nicotine and cotinine in the ranges similar to the levels found in habitual smokers, and a high fat diet (HFD) on cardiac structure and function in a commonly used model of diet-induced obesity (DIO). C57BL/6J mice on an HFD were exposed to e-cigarette in the presence (2.4% nicotine) or absence (0% nicotine) of nicotine and saline aerosol for 12 weeks. Echocardiographic data demonstrated a decrease in left ventricular (LV) fractional shortening, LV ejection fraction, and velocity of circumferential fiber shortening (VCF) in mice treated with e-cigarette (2.4% nicotine) compared to e-cigarette (0% nicotine) or saline exposed mice. Cardiomyocytes (CMs) of mice treated with e-cigarette (2.4% nicotine) exhibited LV abnormalities, including lipid accumulation (ventricular steatosis), myofibrillar derangement and destruction, and mitochondrial hypertrophy, as revealed by transmission electron microscopy. The detrimental effects of e-cigarettes (2.4% nicotine) on cardiac structure and function was accompanied by increased oxidative stress, plasma free fatty acid levels, CM apoptosis, and inactivation of AMP-activated protein kinase and activation of its downstream target, acetyl-CoA-carboxylase. Our results indicate profound adverse effects of e-cigarettes (2.4% nicotine) on the heart in obese mice and raise questions about the safety of the nicotine e-cigarettes use.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cotinine / blood
  • Diet, High-Fat / adverse effects*
  • Echocardiography
  • Electronic Nicotine Delivery Systems*
  • Fatty Acids, Nonesterified / blood
  • Heart / drug effects*
  • Heart / physiopathology
  • Heart Ventricles / drug effects
  • Heart Ventricles / pathology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Obese*
  • Microscopy, Electron, Transmission
  • Myocardium / pathology*
  • Myocardium / ultrastructure
  • Nicotine / adverse effects
  • Nicotine / blood
  • Oxidative Stress / drug effects
  • Smoking / adverse effects*
  • Ventricular Dysfunction, Left / chemically induced


  • Fatty Acids, Nonesterified
  • Nicotine
  • Cotinine