Acute inhalation of cigarette smoke augments hypoxic chemosensitivity in humans

Abstract

Hypoxic and hypercapnic ventilatory responses were measured after two levels of acute inhalation of cigarette smoke, minimum-level nicotine smoke (smoke 1) and nicotine-containing smoke (smoke 2), in 10 normal men. Chemosensitivity to hypoxia and hypercapnia was assessed both in terms of slope factors for ventilation-alveolar PO2 curve (A) and ventilation-alveolar PCO2 line (S) and of absolute levels of minute ventilation (VE) at hypoxia or hypercapnia. Ventilatory response to hypoxia and absolute level of VE at hypoxia significantly increased from 23.5 +/- 22.6 (SD) to 38.6 +/- 31.3 l . min-1 . Torr and from 10.6 +/- 2.5 to 12.6 +/- 3.5 l . min-1, respectively, during inhalation of cigarette smoke 2 (P less than 0.05). Inhalation of cigarette smoke 2 tended to increase the ventilatory response to hypercapnia, and the absolute level of VE at hypercapnia rose from 1.42 +/- 0.75 to 1.65 +/- 0.58 l . min-1 . Torr-1 and from 23.7 +/- 4.9 to 25.5 +/- 5.9 l . min-1, respectively, but these changes did not attain significant levels. Cigarette smoke 2 inhalation induced an increase in heart rate from 64.7 +/- 5.7 to 66.4 +/- 6.3 beats . min-1 (P less than 0.05) during room air breathing, whereas resting ventilation and specific airway conductance did not change significantly. On the other hand, acute inhalation of cigarette smoke 1 changed none of these variables. These results indicate that hypoxic chemosensitivity is augmented after cigarette smoke and that nicotine is presumed to act on peripheral chemoreceptors.

Cigarette Smoking Behavior and Respiratory Alterations During Sleep in a Healthy Population

“…3,8-10 Among all the risk factors evaluated, habitual snoring has been shown in this and other studies [11][12][13] to correlate best with apneic activity during sleep. 3 While it is possible that tobacco-induced inflammatory changes in the upper airway could predispose to upper airway obstruction and disordered breathing during sleep, the observation that tobacco increases sensitivity of chemoreceptors to hypoxia 4,5 suggests that smoking could also protect against central apneas. 8,14 Snoring reflects a partial upper airway obstruction whereas during apnea the obstruction in the pharynx is usually total.…”

“…These include a significant decrease in tidal volume and minute ventilation (hypopnea), respiratory pauses (apneas), and periodic breathing. [3][4][5] The objective of this study was to evaluate the influence of cigarette smoking behavior on the respiratory alterations occurring during sleep in a healthy population. 2 However, the existence of a relationship between cigarette smoking behavior and apneic activity during sleep is disputed.…”

Attenuation of hypercapnic carbon dioxide chemosensitivity after postinfarction exercise training: possible contribution to the improvement in exercise hyperventilation

“…The CO 2 chemosensitivity values in healthy subjects were somewhat lower than previously reported by other studies but were similar to the value reported by Yamamoto and colleagues. 37 Chemosensitivity is known to be lower in the elderly than in the younger subjects 38 and chemosensitivity varies considerably between individual subjects, which may have affected our results.…”

Neonatal Hypoxia Ischaemia: Mechanisms, Models, and Therapeutic Challenges

“…Several studies have documented altered levels of neurotransmitters (Hedner et al, 1980; Kaneko et al, 1985; Yamamoto et al, 1985; Yamamoto and Kato, 1986; Hadjiconstantinou et al, 1990; Seidler and Slotkin, 1990; Dell’Anna et al, 1993; Tanaka et al, 1995; Anju et al, 2010a,b; Anju and Paulose, 2011, 2013). However, there is little consensus over the direction or magnitude of changes (Decker M.J. et al, 2003; Decker et al, 2005).…”