Xerostomia among users of electronic nicotine delivery systems in a multinational web-based cross-sectional study

The use of electronic nicotine delivery systems (ENDS) has increased globally. Evidence of the association between xerostomia and ENDS remains limited. We evaluated the association between nicotine product use and xerostomia severity in a multinational sample from the Middle East and North Africa (MENA) region. In this cross-sectional study, adults aged 18-40 years from 18 MENA countries were recruited via convenience sampling through social media platforms between December 2023 and March 2024. Xerostomia symptoms were assessed using the xerostomia Inventory (XI). Directed acyclic graphs guided confounder selection. Regression models examined the association between nicotine product use and xerostomia symptom scores. Among 11,451 participants (6975 [60.9%] non-users, 1913 [16.7%] exclusive ENDS users, 1778 [15.5%] exclusive combustible tobacco users, and 785 [6.9%] dual users), all current-use categories were associated with higher XI scores than non-use after adjustment for age, sex, and exercise frequency: exclusive ENDS users (standardised β = 0.385; p < 0.001), exclusive combustible tobacco users (β = 0.201; p < 0.001), and dual users (β = 0.324; p < 0.001). Current use of any nicotine product was associated with higher xerostomia scores than non-use, with the strongest associations observed among exclusive ENDS users and dual users.