Smokeless tobacco (snus) is associated with an increased risk of type 2 diabetes: results from five pooled cohorts.
Smoking and nicotine exposure increase insulin resistance and the risk of type 2 diabetes. Swedish smokeless tobacco (snus) is high in nicotine, and its use is prevalent in Scandinavian countries, but few studies have investigated snus use in relation to diabetes risk.



To explore the association between snus use and risk of type 2 diabetes using pooled data from five cohorts.



Analyses were based on prospective studies conducted between 1990 and 2013 including 54 531 never-smoking men and 2441 incident cases of type 2 diabetes identified through screening, self-reporting and hospital and prescription registries. Hazard ratios (HRs) and 95% confidence intervals (CIs) were assessed and adjusted for age, body mass index, educational level, alcohol consumption and physical activity.



Compared to never users, the HR of type 2 diabetes was 1.15 (95% CI: 1.00-1.32) in current users of snus. In individuals consuming 5-6 boxes per week, the HR was 1.42 (95% CI: 1.07-1.87); in those consuming ≥7 boxes per week, the HR was 1.68 (95% CI: 1.17-2.41). Each additional box of snus consumed per week yielded an HR of 1.08 (95% CI: 1.01-1.16).



Our findings indicate that high consumption of snus is a risk factor for type 2 diabetes. The risk was similar to that in smokers, implying that smokers will not reduce their risk of type 2 diabetes by changing to snus use. The results also support the notion that nicotine increases the risk of type 2 diabetes.
Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
S
S
Carlsson
Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.|Center for Occupational and Environmental Medicine, Stockholm County Council, Stockholm, Sweden.
T
T
Andersson
Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden.
M
M
Araghi
Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden.|Centre for Epidemiology and Community Medicine, Stockholm County Council, Stockholm, Sweden.
R
R
Galanti
Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden.|Centre for Epidemiology and Community Medicine, Stockholm County Council, Stockholm, Sweden.
A
A
Lager
Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden.|Centre for Epidemiology and Community Medicine, Stockholm County Council, Stockholm, Sweden.
M
M
Lundberg
Department of Clinical Sciences, Lund University, Skåne University Hospital, Malmö, Sweden.
P
P
Nilsson
Epidemiology and Global Health, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
M
M
Norberg
Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
N L
NL
Pedersen
Department of Medicine, Karolinska Institutet, Stockholm, Sweden.
Y
Y
Trolle-Lagerros
Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden.|Centre for Epidemiology and Community Medicine, Stockholm County Council, Stockholm, Sweden.
C
C
Magnusson
D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D014030:Tobacco, Smokeless / Q000706:statistics & numerical data*
meta-analysis; public health; tobacco; type 2 diabetes