The effect of heated tobacco products on metabolic syndrome: A cohort study.

Introduction: Evidence concerning the health effects of using heated tobacco products is needed. The aim of the present study is to investigate the effects of conventional cigarettes (CCs), electronic vaping cigarettes (EVCs), and heated tobacco products (HTPs) on the development of metabolic syndrome.

Methods: We conducted a cohort study in South Korea using data from the Korea Medical Institute. The study included 183870 people who visited the Korea Medical Institute, responded to a smoking status questionnaire in 2019, and were followed up in 2020 - ever and current use of CCs, EVCs, and HTPs. We defined the main outcome as incident metabolic syndrome among participants with at least two health checkups separated by a follow-up period of at least a year.

Results: The association of using HTPs with risk for metabolic syndrome was estimated after controlling for age, sex, exercise, drinking history, and smoking regular cigarettes and using EVCs, with the Cox proportional hazards model. The risk of incident metabolic syndrome was increased by 68% (HR=1.68; 95% CI: 1.25-2.26) for current HTP users compared to never users. Among HTP users who did not currently smoke conventional cigarettes, the risk was doubled (HR=2.17; 95% CI: 1.31-3.62) when their smoking duration was ≥3 years. The risk of metabolic syndrome increased by 33% (HR=1.33; CI: 1.18-1.49) among HTP users who used them more than 16 times a day. The use of HTP was found to increase the risk of developing metabolic syndrome, with a particularly elevated risk observed among those who used HTPs for more than three years. The risk was higher than that observed in conventional cigarette users.

Conclusions: Our findings indicate that HTP use poses comparable risks in relation to metabolic syndrome development.