title: Cerebral oxygenation and sympathetic responses to smoking in young and middle-aged smokers.
abstract: This study examined the effects of acute tobacco smoking on cerebral oxygenation and autonomic function in 28 male, habitual smokers of shorter young smokers (YSM) or longer middle-aged smokers (MSM) smoking history. Following baseline testing, participants undertook a smoking protocol involving the consumption of two cigarettes within 15 min. Measures of cerebral oxygenation and autonomic function were collected before, during, and 0 min, 30 min, 1 h, and 4 h post-smoking. Tissue saturation index (TSI) for MSM was greater than YSM during cigarette consumption ( p < 0.05). Moreover, MSM observed significant within-group changes for TSI during and post-cigarette consumption ( p < 0.05). Further, MSM observed an increase in low frequency (LF) band from 30 min to 1 h post-consumption, followed by a decline, whereas elevations above MSM were observed in YSM at 4 h ( p < 0.05). Both MSM and YSM showed a decrease in high-frequency (HF) band post-cigarette, while increased LF/HF ratio post-consumption was observed in YSM. A decline in the standard deviation of RR intervals, post-cigarette consumption was evident in MSM ( p < 0.05). Moreover, the root mean square of RR interval in both groups similarly decreased following cigarette consumption ( p < 0.05). Acute smoking affects heart rate variability, suggestive of vagal withdrawal, and maybe indicate an effect of smoking history. Additionally, prolonged smoking history alters cerebral microcirculatory responses to acute tobacco exposure in MSM.
authors.affiliation: 1 School of Exercise Science, Sport and Health, Charles Sturt University, Bathurst, NSW, Australia.
authors.forename: T E
authors.initials: TE
authors.lastname: Kastelein
authors.affiliation: 2 Sport and Exercise Discipline Group, UTS: Health, University of Technology Sydney (UTS), Moore Park, NSW, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Duffield
authors.affiliation: 2 Sport and Exercise Discipline Group, UTS: Health, University of Technology Sydney (UTS), Moore Park, NSW, Australia.|3 New South Wales Institute of Sport, Sydney Olympic Park, NSW, Australia.
authors.forename: S
authors.initials: S
authors.lastname: Crowcroft
authors.affiliation: 1 School of Exercise Science, Sport and Health, Charles Sturt University, Bathurst, NSW, Australia.
authors.forename: F E
authors.initials: FE
authors.lastname: Marino
mesh_terms: D000328:Adult; D001794:Blood Pressure; D001921:Brain / Q000378:metabolism*; D015331:Cohort Studies; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism*; D019265:Spectroscopy, Near-Infrared; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: Tobacco; autonomic function; near-infrared spectroscopy