Cigarette and noncigarette smoke exposure increases sympathetic nerve activity and attenuates baroreflex suppression, though autonomic function may be restored after smoking cessation.
Does exposure to cigarette and noncigarette smoke adversely affect autonomic function?
This review highlights the mechanisms by which smoke exposure increases sympathetic nerve activity and suppresses baroreflex sensitivity, reinforcing the cardiovascular benefits of smoking cessation.
This review summarizes the detrimental effects of cigarette and noncigarette emission exposure on autonomic function, with particular emphasis on the mechanisms of acute and chronic modulation of the sympathetic nervous system. We propose that the nicotine and fine particulate matter in tobacco smoke lead to increased sympathetic nerve activity, which becomes persistent via a positive feedback loop between sympathetic nerve activity and reactive oxidative species. Furthermore, we propose that baroreflex suppression of sympathetic activation is attenuated in habitual smokers; that is, the baroreflex plays a permissive role, allowing sympathoexcitation to occur without restraint in the setting of increased pressor response. This model is also applicable to other nontobacco cigarette emission exposures (e.g., marijuana, waterpipes hookahs, electronic cigarettes, and even air pollution). Fortunately, emerging data suggest that baroreflex sensitivity and autonomic function may be restored after smoking cessation, providing further evidence in support of the health benefits of smoking cessation.
“When the sympathetic nervous system fires, like with MSNA, your blood pressure rises and then a series of things happen to buffer that increase, to try to attenuate it. We think that in smokers, that buffering — the baroreflex — is impaired.”
Middlekauff et al. (2014) conducted a review in Smoke exposure. Cigarette and noncigarette smoke exposure was evaluated on Autonomic function and sympathetic nerve activity. Cigarette and noncigarette smoke exposure increases sympathetic nerve activity and attenuates baroreflex suppression, though autonomic function may be restored after smoking cessation.