Preliminary study on the effect of first- and second-hand smoke of heat-not-burn tobacco products on urinary nicotine and cotinine levels and cardiovascular system

Heart rate variability (HRV) of 10 participants was assessed to evaluate the impact of exposure to first- and second-hand smoke from heat-not-burn (HnB) products and conventional cigarettes on cardiovascular health and the autonomic nervous system. The nicotine and cotinine concentrations in the urine of smokers and non-smokers exposed to this smoke were also measured. Nicotine levels in the urine of smokers exposed to HnB products and conventional cigarettes averaged 71.76 and 229.36 ng/ml, respectively. Short-term analyses of HRV in both time- and frequency-domain were performed. There were no significant differences in HRV indicators between both groups at baseline. However, decreases in SDNN, rMSSD, TINN, and pNN50 (%) were observed in smokers exposed to both first- and second-hand smoke from HnB products and conventional cigarettes. No significant trends were noted in non-smokers. The frequency-domain analysis revealed a decrease in low frequency components among smokers.