The effect of tobacco- and electronic cigarettes use on the olfactory function in humans

Abstract

Electronic cigarettes are a recent development in tobacco harm reduction. They are marketed as a “healthier alternative” to conventional cigarettes but their health impact is unknown. Therefore, the aim of this study was to investigate the odor perception of smokers and vapers (e-cigarette consumers) in comparison to non-smokers. For the study 181 study participants aged 18 to 46 years were selected and divided into three groups including the control group (n = 70 non-smokers; 40 women, 30 men), as well as two investigated groups consisted of smokers (n = 66; 32 women, 34 men) and vapers (n = 45; 18 women, 27 men). The individuals were evaluated by applying the “Sniffin‘ Sticks” odor threshold (T), discrimination (D), and identification (I) test. To express the overall results a composite threshold-discrimination-identification (TDI) score was calculated. The results of the threshold test showed a significant difference (p ≤ 0.05) between non-smokers and smokers, as well as smokers and vapers. The data of odor discrimination- and odor identification, as well as the TDI-score revealed a significant difference (p ≤ 0.05) between all three evaluated groups. Furthermore, according to the Pearson test, there was a significant correlation (p ≤ 0.05) between the “pack-years” and odor threshold and the TDI-score. However, the correlation between the “pack-years” and the results of the odor discrimination and identification was not statistically significant (p > 0.05). Besides, the duration of vaping (in years) and amount of consumed liquid (ml) did not correlate (p > 0.05) with the odor threshold, discrimination, identification as well as the TDI-score. Finally, it can be stated that the non-smoker group exhibited the best performance in the conducted olfactory tests, closely followed by the vapers. In contrast, the consumption of cigarettes had a negative impact on the olfactory perception of smokers.