title: High consumption of smokeless tobacco ("snus") predicts increased risk of type 2 diabetes in a 10-year prospective study of middle-aged Swedish men.
abstract: OBJECTIVE
  Cigarette smoking increases the risk of type 2 diabetes (T2D). In Sweden and the US, people shift from smoking cigarettes to smokeless tobacco, i.e. oral moist snuff, "snus", to attain harm-reduction. There are limited and conflicting data as to whether snus increases the risk of T2D. The present study investigated if snus use predicts the risk of T2D incidence.
  
  
  METHODS
  This is a prospective population-based study where middle-aged Swedish men (n=2,383), without previously diagnosed T2D, were investigated with oral glucose tolerance test (OGTT) at baseline in 1992-94 and at follow-up 10 years later. Odds ratios (ORs) for newly diagnosed T2D at follow-up were assessed among those using snus, or cigarettes, at both baseline and follow-up, adjusted for major confounders.
  
  
  RESULTS
  The OR for T2D was not significantly increased in the whole group of snus users. However, the risk of diabetes increased with increasing weekly snus consumption; ORs (CIs) for >four boxes of snus/week were 2.1 (CI 0.9-4.9), and for >five boxes/week 3.3 (CI 1.4-8.1). For comparison, men smoking at baseline and still smoking at follow-up had an increased risk of diabetes compared with never smokers, OR 1.5 (CI 0.8-3.0), most evident for those smoking >15 cigarettes per day, OR 2.4 (CI 1.0-5.8). Tobacco use was associated with estimations of low insulin response (OGTT), but not low insulin sensitivity (HOMA).
  
  
  CONCLUSIONS
  High consumption of snus, like smoking, predicts risk of developing T2D. This should be considered when seeking harm-reduction by changing from use of cigarettes to snus. T2D risk from tobacco use may be mediated by effects on beta-cell function.
authors.affiliation: Department of Molecular Medicine and Surgery, Endocrine and Diabetes Unit, Karolinska Institutet, Stockholm, Sweden. claes-goran.ostenson@ki.se
authors.forename: Claes-Göran
authors.initials: CG
authors.lastname: Östenson
authors.forename: Agneta
authors.initials: A
authors.lastname: Hilding
authors.forename: Valdemar
authors.initials: V
authors.lastname: Grill
authors.forename: Suad
authors.initials: S
authors.lastname: Efendic
mesh_terms: D000328:Adult; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D005500:Follow-Up Studies; D005951:Glucose Tolerance Test; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011446:Prospective Studies; D018570:Risk Assessment; D013548:Sweden / Q000453:epidemiology; D014030:Tobacco, Smokeless / Q000009:adverse effects*