Health effects of Swedish snus – adverse impacts on asthma, respiratory symptoms and snoring?

Introduction: Snus is a very popular tobacco-alternative in Sweden with 18% of males and 4% of females being current snus users. Studies aiming to reveal the health effects of snus use have not reported unanimous observations although most indicate beneficial health effects compared to smoking. The main objective of this study was to examine health effects of snus use on asthma, respiratory symptoms and sleep related problems, a field that has not been investigated before. Methods and material: This cross-sectional study is based on observations from a postal questionnaire completed by 26,697 (59.3%) participants aged 16-75 living in Sweden. The questionnaire included questions regarding usage of snus, smoking history, asthma, asthma related symptoms, other respiratory symptoms, sleeping problems and chronic diseases. Multivariable logistic regression models were used to study independent association between various symptoms and different groups of tobacco use after adjusting for potential confounders; sex, age, body mass index, centre, educational level and physical activity. Results: Snus use was associated with having asthma (OR [95% CI] = 1.51 [1.28-1.77]) but being a smoker or dual user of snus and cigarettes was not. Current snus users who had never smoked had an increased risk of suffering from asthma, asthmatic symptoms, chronic bronchitis and chronic rhinosinusitis. This association was not present among ex-snus users. Snoring was independently related to both ex- and current use of snus among never smokers ((OR [95% CI] = 1.37 [1.12-1.68]) and (OR [95% CI] = 1.59 [1.34-1.89]), respectively). The risk of snoring increased when the examination was restricted to only those suffering from asthma (OR [95% CI] = 2.68 [1.58-4.55]). A higher risk of difficulty inducing sleep was seen among current snus users who had never smoked. Current snus use showed a negative association with difficulty maintaining sleep (OR [95% CI] = 0.72 [0.60-0.85]) whereas ex-snus users had an increased risk of the problem (OR [95% CI] = 1.20 [1.01-1.42]). Being an ex-snus user was also an independent risk factor for early morning awakenings. Conclusion: The fact that the risk of snoring was elevated both among ex- and current snus users suggests a partly irreversible effect from snus use on limited flow of air in the upper respiratory tract. Asthmatic patients seem to be even more sensitive to the possible effects of snus contributing to snoring. Snus might also lead to reversible effects resulting in inflammation and mucus secretion contributing to an elevated risk of asthma and respiratory symptoms among current snus users. Health care professionals should be aware of these possible health effects from snus use when treating patients dependent on snus and campaigns against snus use should be even more vigorous than before