[Background] To investigate long-term health effects of heated tobacco products (HTPs) use, changes of cardiovascular risks and respiratory function over 5 years were compared between exclusive users of HTPs (switcher) and those with those quitting smoking (quitter).

[Subjects and Methods] Male employees of a company, who gave informed consent, were enrolled (201 switchers vs 216 quitters). The data of demographics, blood pressure (BP), pulmonary function, cholesterol levels and inflammation markers, were derived from their annual health chechup data, and changes over 5 years were determined in each group, and then compared between switchers and quitters.

[Results] Baseline age, smoking history, and periods after switching or quitting of switchers and quitters were 41.2±10.7 vs 41.4±9.3 years old (p=0.81), 18.4±13.5 vs 20.2±13.2 packyear, 57±10 vs 63±7 months (p<0.01), respectively. White blood cell count (WBC) decreased, and HDL-cholesterol increased significantly during 5 years in both groups. BP and peak flow (PEF) increased in switchers (both, p<0.01), whilst they did not in quitters. Crude annual decline of FEV1.0 in switchers and quitters were -20.0±46.0 vs -37.5±57.5 ml/year, respectively, but did not achieve any statistical significance after multivariable adjustment.

[Conclusion] Improvement in WBC and HDL-cholesterol levels reflected restored systemic inflammation and that in FEV1.0 reflected local inflammation, suggesting that inflammatory responses are the same between switchers and quitters. However, the increase in BP and PEF  were observed in switchers, possibly due to activation of sympathetic nervous sytem by nicotine