Associations between snus use and concentrations of CRP, 25(OH)D and testosterone: a population-based study

Previous research suggests that the use of snus, a smokeless tobacco product, is associated with increased all-cause and cardiovascular mortality, but the underlying mechanisms are unknown. We aimed to evaluate the associations of snus use with biomarkers of cardiometabolic importance: high-sensitivity C-reactive protein (hs-CRP), 25-hydroxyvitamin D (25(OH)D) and calculated free testosterone (cfT). We performed cross-sectional analyses within the population-based Northern Sweden MONICA-study. The study sample consisted of 6 158 never-smoking men and women (of whom 21 and 3.3% were current snus users, respectively), examined between 1990 and 2014. Harmonized analyses on biomarkers were conducted 2016 to 2018. We evaluated the relationships between snus use and biomarker concentrations using linear and logistic regression. Snus use, compared to never-use, was associated with lower hs-CRP (exp(βln) 0.88, 95% CI 0.81; 0.96) and 25(OH)D-concentrations (β - 1.01, 95% CI -1.70; -0.33) in mixed-sex analyses. Among men, snus use was also associated with higher cfT-concentrations (exp(βln) 1.04, 95% CI 1.01; 1.07). Former snus users had no significant differences in biomarker concentrations. Snus users have lower concentrations of 25(OH)D and hs-CRP, irrespective of sex, while male users have higher cfT-concentrations. These findings may in part contribute to the previously observed increased mortality among snus users.