Background: Evidence suggests an association of oral moist tobacco (snus) with higher risk of asthma, asthma-symptoms, and chronic bronchitis among never smokers. However, there is no knowledge of whether time at snus initiation plays a role for respiratory outcomes.

Objective: To investigate associations of snus use starting in puberty (?15 years of age) and after, with asthma and asthma-like symptoms.

Methods: Questionnaire data on tobacco habits and respiratory outcomes were obtained in Norway, Sweden, Denmark, Iceland, and Estonia from 9002 responders [median age 29 years (15-72); 58% females] from the Respiratory Health In Northern Europe, Spain and Australia (RHINESSA) study in 2013-16. Time at snus initiation was classified as never (reference), ?15, or >15 years of age. Multilevel logistic regression models adjusted for age and smoking, and stratified by sex were used to analyze associations of time at snus initiation and 1) asthma-like symptoms (?3 vs. <3), and 2) asthma medication use and/or asthma attacks in the last 12 months (yes vs. no).

Results: Snus use was reported by 20.4% of the participants of whom 21.7% had started in puberty. Women using snus in puberty had a higher OR for asthma-like symptoms (OR 2.54; 95%CI 1.37-4.70) and for asthma medication/attacks (OR 1.70; 95%CI 0.87-3.31) compared to never users. No significant effect could be identified for early onset snus use in males (OR 1.15; 95%CI 0.74-1.79) or late initiation in either of the sexes.

Conclusions: Many snus users in Northern Europe start consumption at an early age. Our results indicate that use of snus starting in puberty could increase the risk of respiratory symptoms in women.