LAUSR

During the COVID-19 era, the use of surgical face mask hampers the spread of COVID infection. The impact of smoking while wearing a surgical face mask on exhaled CO and vascular function in smokers has not been investigated. We studied 40 smokers of conventional cigarettes (ConCig), 40 exclusive heat-non-burn cigarettes (HNBC) users and 40 non-smokers with similar age and sex (p>0.05 [45.1±10.8 years, 34 (28.3%) male]. We measured exhaled CO (parts per million [ppm]), pulse wave velocity (PWV) and central systolic blood pressure (cSBP). A significant interaction was found between CO at baseline and at the end of an 8h period with and without wearing a mask and the use of tobacco products vs no-smoking (F=46.58, p for interaction<0.001). Exhaled CO was higher in ConCig smokers compared to HNBC and nonsmokers throughout the study (p<0.05). Compared to baseline, the percent increase of CO was greater after smoking ConCig with than without wearing a mask for 8h (141.79% [95% confidence interval (CI): 116.16–167.42] vs 56.99% [95% CI: 44.80–69.18], p<0.001). Similarly, the percent increase of CO was greater after smoking HNBC with than without wearing a mask for 8h (103.84% [95% CI: 70.50–137.18] vs 30.76% [95% CI: 15.61–45.92], p<0.001). Among non-smokers, the use of mask did not alter exhaled CO (p>0.05). In both ConCig and HNBC users, all vascular markers were increased at the end of each one of two study assessments, compared to baseline (p<0.05). In non-smokers, the use of a mask had a neutral effect on vascular markers (p>0.05). Compared to baseline, the percent increase of PWV was greater after smoking ConCig with than without wearing a mask for 8h (16.54% [95% CI: 9.13–23.95] vs 4.36% [95% CI: 1.41–7.31], p=0.001). Compared to baseline, the percent increase of PWV was greater after smoking HNBC with than without wearing a mask for 8h (9.71% [95% CI: 4.57–14.84] vs 2.73% [95% CI: 0.12–5.35], p=0.003). Ssmoking of any tobacco product (conventional tobacco or HNBC) during a prolonged use of a surgical face mask may further compromise vascular function. Thus, quitting both conventional and HNBC cigarettes is imperative for a better health in the COVID-19 pandemic. Type of funding sources: None.