Cardiovascular, carcinogenic and reproductive effects of nicotine exposure: A narrative review of the scientific literature

Abstract

The emergence of new tobacco heating products and electronic nicotine delivery systems (ENDS) is changing the way humans are exposed to nicotine. The purpose of this narrative review is to provide a broad overview of published scientific literature with respect to the effects of nicotine on three key health-related areas: 1) cardiovascular risk, 2) carcinogenesis and 3) reproductive outcomes. These areas are known to be particularly vulnerable to the effects of cigarette smoke, and in addition, nicotine has been hypothesized to play a role in disease pathogenesis. Acute toxicity will also be discussed. The literature to February 2019 suggests that there is no increased cardiovascular risk of nicotine exposure in consumers who have no underlying cardiovascular pathology. There is scientific consensus that nicotine is not a direct or complete carcinogen, however, it remains to be established whether it plays some role in human cancer propagation and metastasis. These cancer progression pathways have been proposed in models in vitro and in transgenic rodent lines in vivo but have not been demonstrated in cases of human cancer. Further studies are needed to determine whether nicotine is linked to decreased fertility in humans. The results from animal studies indicate that nicotine has the potential to act across many mechanisms during fetal development. More studies are needed to address questions regarding nicotine exposure in humans, and this may lead to additional guidance concerning new ENDS entering the market.

Differences in Hemodynamic Status in Users of Tobacco Cigarettes and E-Cigarettes

“…In addition, norepinephrine also binds to 2 adrenergic receptors on the surface of smooth muscle cells causing inhibition of adenylate activity. [25] Nicotine is a sympathomimetic drug that acts on nicotinic receptors located throughout the autonomic nervous system to increase sympathetic nervous and catecholamine release. Thus, it is not surprising that acute exposure to cigarettes with nicotine can increase the sympathetic nervous system.…”

Nicotine and Inflammatory Disease in Humans: A Systematic Review

“…The acute effects of nicotine on vascular function have been extensively investigated, whereby the mechanisms predominantly manifest through stimulation of the sympa-thetic nervous system and activation of the hypophysis adrenal axis leading to increased plasma levels of adrenocorticotropic hormone (ACH), cortisol and adrenaline (39). The development of atherosclerosis, however, is a chronic process.…”

“…Mechanisms have been proposed via in vitro and in vivo animal studies involving particularly the activation of α7 nicotinic receptors. However, there is also conflicting evidence arising from these models (39). Longitudinal studies in human participants that consider smoking history will be necessary to assess the risk of atherosclerosis in relation to nicotine use and inflammation.…”

Daily Lifestyle and Inflammatory Skin Diseases

“…Smoking causes many physiological and pathological adverse effects on human health and increases mortality associated with health risks such as malignancies and cardiovascular events [ 78 ]. In addition to these risks, inflammatory skin diseases are closely related to smoking.…”